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2017

3D Navigation Tool among MESSENGER's Final Delivery Products to the Planetary Data System - May 18, 2017
NASA’s MESSENGER mission to Mercury has released an updated ACT-QuickMap tool with new 3D navigation capabilities as illustrated by this “fly around” view of the Caloris impact basin. This update was among the new and improved products released by the agency’s Planetary Data System (PDS), an organization that archives and distributes all U.S. planetary mission data.

2016

First Global Topographic Model of Mercury among MESSENGER’s Latest Delivery to the Planetary Data System - May 6, 2016
The MESSENGER mission has released the first global digital elevation model (DEM) of Mercury, revealing in stunning detail the topography across the entire innermost planet and paving the way for scientists to characterize fully the planet’s geologic history.

MESSENGER Data May Reveal the Remains of Mercury's Oldest Crust - March 7, 2016
Mercury's surface is unusually dark, an observation that until recently had planetary scientists mystified. But in a new study published today in Nature Geoscience, a team of researchers provides evidence that the darkening agent is carbon, a finding that offers important clues to the nature of the planet's original crust.

2015

MESSENGER's Brett Denevi Awarded Top Scientist Honor from Maryland Academy - November 24, 2015
The Maryland Academy of Sciences presented MESSENGER Team Member Brett Denevi with their Outstanding Young Scientist award during a ceremony on November 18 at the Maryland Science Center in Baltimore.

Former MESSENGER Mission Manager Robert Farquhar Dies at Age 83 - October 23, 2015
Robert W. Farquhar, an early MESSENGER Mission Manager and a planetary trajectory pioneer who designed some of the most esoteric and complex spacecraft trajectories ever attempted, died on October 18, at the age of 83. A 50-year veteran of deep-space missions, Farquhar made pivotal contributions to the exploration of comets, asteroids, and the planets.

Planetary Data System Releases 14th Delivery of MESSENGER Data - October 9, 2015
Data collected during MESSENGER's 43rd through 49th months in orbit around Mercury were released to the public today by NASA's Planetary Data System (PDS), the network of nodes that archives and distributes data from NASA's planetary missions. With this release, all data acquired by the MESSENGER mission are now available online - data collected through eight full Mercury solar days of orbit about the innermost planet in our solar system.

MESSENGER Team Celebrates 11th Anniversary of Launch - August 3, 2015
Eleven years ago today -- at 2:15:56 am EDT -- NASA's MESSENGER spacecraft was launched aboard a Boeing Delta II rocket from Cape Canaveral Air Force Station in Florida, and after more than 6 1/2 years in transit it became the first spacecraft to orbit the innermost planet in our solar system.

MESSENGER Finds Evidence of Ancient Magnetic Field on Mercury - May 7, 2015
Mercury's magnetic field, generated by a dynamo process in its outer core, has been in place far longer than previously known, a paper by MESSENGER Participating Scientist Catherine Johnson reports.

NASA Completes MESSENGER Mission with Expected Impact on Mercury's Surface - April 30, 2015
Mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., confirmed today that NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft impacted the surface of Mercury, as predicted, at 3:26 p.m. EDT this afternoon (3:34 p.m. ground time).

Mercury Crater-Naming Contest Winners Announced - April 29, 2015
The MESSENGER Education and Public Outreach Team, coordinated through the Carnegie Institution for Science, announces the winning names from its competition to name five impact craters on Mercury: Carolan, Enheduanna, Karsh, Kulthum, and Rivera.

MESSENGER Executes Last Orbit-Correction Maneuver, Prepares for Impact - April 25, 2015
MESSENGER mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., conducted the last of six planned maneuvers on April 24 to raise the spacecraft's minimum altitude sufficiently to extend orbital operations and further delay the probe's inevitable impact onto Mercury's surface.

NASA Celebrates MESSENGER Mission Prior to Surface Impact of Mercury - April 16, 2015
NASA's highly successful MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft is coming to the end of its operations. Mission engineers predict that the probe -- out of fuel and under gravity's spell -- will impact Mercury on April 30 at more than 8,750 miles per hour (3.91 kilometers per second).

Nothing but Helium: Correction Maneuver Puts MESSENGER Right on Course - April 9, 2015
The MESSENGER team is pulling out all the stops to give the spacecraft life far beyond its original design. On April 8, mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., successfully conducted a contingency orbit-correction maneuver (OCM-15a), to supplement the April 6 burn (OCM-15) that concluded early when the last drops of hydrazine fuel were expended.

Latest Maneuver Illustrates Critical Role Telecommunications System Plays in Delaying MESSENGER's Mercury Impact - April 7, 2015
MESSENGER's orbit-correction maneuver on April 6 was a nail biter. It was the 15th such maneuver since the spacecraft entered orbit about Mercury in 2011, and the third in a series of increasingly risky "burns" designed to delay MESSENGER's inevitable impact onto Mercury's surface. Each maneuver illustrates the critical role that the spacecraft's radio frequency (RF) telecommunications system plays in its operation.

Planned Maneuver Further Extends MESSENGER Orbital Operations - April 3, 2015
MESSENGER mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., conducted a maneuver yesterday to raise the spacecraft's minimum altitude sufficiently to extend orbital operations and further delay the probe's inevitable impact onto Mercury's surface.

MESSENGER Completes 4,000th Orbit of Mercury - March 27, 2015
On March 25, the MESSENGER spacecraft completed its 4,000th orbit of Mercury, and the lowest point in its orbit continues to move closer to the planet than ever before.

MESSENGER's Endgame: Hover Campaign Promises Bird's-Eye View of Mercury's Surface - March 18, 2015
MESSENGER will not go gentle into that good night. The mission will end sometime this spring, when the spacecraft runs out of propellant and the force of solar gravity causes it to impact the surface of Mercury. But the team initiated a "hover" observation campaign designed to gather scientific data from the planet at ultra-low altitudes until the last possible moment. Engineers have devised a series of orbit-correction maneuvers (OCMs) over the next five weeks -- the first of which was carried out today -- designed to delay the inevitable impact a bit longer.

With the End in Sight, the MESSENGER Team Celebrates Fourth Orbital Anniversary - March 17, 2015
Today, the MESSENGER team celebrates the fourth anniversary of the spacecraft's Mercury orbit insertion. On the evening of March 17, 2011 (EDT), the spacecraft made history when it became the first to orbit the innermost planet. Over the last four years, its instruments have fully mapped Mercury's surface and yielded discoveries that have changed views on how the inner planets formed and evolved.

Scientists Discuss New Results from MESSENGER's Low-Altitude Campaign - March 16, 2015
The Woodlands, Texas -- NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission, now nearing the end of its fourth and final year of orbital operations at Mercury, is well into a low-altitude campaign that is returning images and measurements of the planet's surface and interior that are unprecedented in their resolution. MESSENGER scientists will discuss new findings from the low-altitude campaign and their implications for Mercury's geological evolution and the planet's geophysical and geochemical characteristics at a press briefing today at the 46th Lunar and Planetary Science Conference. Presentation materials and presenter biographies are available online.

New MESSENGER Maps of Mercury's Surface Chemistry Provide Clues to the Planet's History - March 13, 2015
Two new papers from members of the MESSENGER Science Team provide global-scale maps of Mercury's surface chemistry that reveal previously unrecognized geochemical terranes -- large regions that have compositions distinct from their surroundings. The presence of these large terranes has important implications for the history of the planet.

Latest MESSENGER Data Delivery Includes New Targeted Mosaics of Mercury - March 6, 2015
NASA's Planetary Data System (PDS) today released data collected from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission during its 37th through 42nd months in orbit about Mercury.

Maneuver Successfully Delays MESSENGER's Impact, Extends Orbital Operations - January 21, 2015
MESSENGER mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., successfully conducted a maneuver today designed to raise the spacecraft's minimum altitude sufficiently to extend orbital operations and delay the probe's inevitable impact onto Mercury's surface until early spring.

Last Chance: Mercury Crater-Naming Contest Ends January 15 - January 13, 2015
The MESSENGER Education and Public Outreach (EPO) Team is reminding interested parties that the competition to name five impact craters on Mercury closes on January 15, 2015. The contest, open to everyone except members of the mission's EPO team, was launched on December 15, 2014.

2014

Innovative use of Pressurant Extends MESSENGER's Mission, Enables Collection of New Data - December 24, 2014
The MESSENGER spacecraft will soon run literally on fumes. After more than 10 years traveling in space, nearly four of those orbiting Mercury, the spacecraft has expended most of its propellant and was on course to impact the planet's surface at the end of March 2015. But engineers on the team have devised a way to use the pressurization gas in the spacecraft's propulsion system to propel MESSENGER for as long as another month, allowing scientists to collect even more data about the planet closest to the Sun.

MESSENGER Team Launches "Name a Crater" Competition - December 16, 2014
The MESSENGER Education and Public Outreach Team is holding a competition to name five impact craters on Mercury. The contest, open to all Earth citizens except for members of the mission's EPO team, runs from December 15, 2014, to January 15, 2015.

Third of Four Planned Maneuvers Extends MESSENGER Orbital Operations - October 24, 2014
MESSENGER mission controllers at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., conducted the third of four maneuvers today to raise the spacecraft's minimum altitude sufficiently to extend orbital operations and delay the probe's inevitable impact onto Mercury's surface until early next spring.

MESSENGER Provides First Optical Images of Ice Near Mercury's North Pole - October 15, 2014
NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft has provided the first optical images of ice and other frozen volatile materials within permanently shadowed craters near Mercury's north pole.

MESSENGER's View of This Week's Lunar Eclipse - October 10, 2014
As millions of people observed the total lunar eclipse on October 8, MESSENGER was also watching. From its orbit about Mercury, the probe's camera captured several images of the Moon as it passed behind Earth and into the planet's shadow. From those images, the team created this movie, released today.

MESSENGER Systems Engineer Receives Inaugural Heinlein Award - October 7, 2014
Daniel O'Shaughnessy has been named the first recipient of the Heinlein Award for his development of solar sailing, a navigational technique that exploits the pressure of sunlight to control a spacecraft.

MESSENGER Principal Investigator to Receive National Medal of Science - October 3, 2014
MESSENGER Principal Investigator Sean Solomon will receive the nation's top scientific honor, the National Medal of Science. Solomon, the director of Columbia University's Lamont-Doherty Earth Observatory, will be awarded the medal at a White House ceremony later this year.

Second of Four Planned Maneuvers Extends MESSENGER Orbital Operations - September 12, 2014
MESSENGER mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., conducted the second of four maneuvers designed to raise the spacecraft's minimum altitude sufficiently to extend orbital operations and delay the probe's inevitable impact onto Mercury's surface until early next spring.

Twelfth Batch of MESSENGER Data Released; Water Ice Exploration Tool Unveiled - September 5, 2014
Data collected during MESSENGER's 31st through 36th month in orbit around Mercury were released to the public today by the Planetary Data System (PDS), an organization that archives and distributes NASA's planetary mission data. With this release, data are now available to the public through the sixth full Mercury solar day of MESSENGER orbital operations.

MESSENGER Team Celebrates 10th Anniversary of Launch - August 1, 2014
Ten years ago, on August 3, 2004, NASA's MESSENGER spacecraft blasted off from Cape Canaveral, Florida, for a risky mission that would take the small satellite dangerously close to Mercury's surface, paving the way for an ambitious study of the planet closest to the Sun. In celebration of the 10th anniversary of its launch, the MESSENGER team has released a movie acquired during an early stage of MESSENGER's low-altitude campaign.

MESSENGER Gets Closer to Mercury than Ever Before - July 28, 2014
On July 25, MESSENGER moved closer to Mercury than any spacecraft has before, dropping to an altitude at closest approach of only 100 kilometers (62 miles) above the planet's surface.

MESSENGER and STEREO Measurements Open New Window Into High-Energy Processes on the Sun - July 9, 2014
Understanding the Sun from afar isn't easy. How do you figure out what powers solar flares -- the intense bursts of radiation coming from the release of magnetic energy associated with sunspots -- when you must rely on observing only the light and particles that make their way to Earth's orbit? One answer: you get closer.

MESSENGER Modifies Orbit to Prepare for Low-Altitude Campaign - June 17, 2014
MESSENGER successfully completed the first orbit-correction maneuver of its Second Extended Mission this morning to raise its minimum altitude above Mercury from 113.9 kilometers (70.8 miles) to 155.1 kilometers (96.4 miles). This maneuver is the first of four designed to modify the spacecraft's orbit around Mercury so as to delay the spacecraft's inevitable impact onto Mercury's surface and allow scientists to continue to gather novel information about the innermost planet.

MESSENGER Completes Its 3,000th Orbit of Mercury, Sets Mark for Closest Approach - April 21, 2014
On April 20, MESSENGER completed its 3,000th orbit of Mercury and moved closer to the planet than any spacecraft has been before, dropping to an altitude of 199 kilometers (123.7 miles) above the planet's surface.

Team Celebrates Orbital Anniversary, Reports on New Findings at Planetary Conference - March 17, 2014
Today, the MESSENGER team celebrates the third anniversary of the probe's Mercury orbit insertion. On March 17, 2011 (Eastern Daylight Time), the spacecraft made history when it became the first probe to orbit the innermost planet. Over the last three years, MESSENGER instruments have fully mapped Mercury's surface and yielded discoveries that have changed views on how the inner planets formed and evolved.

Mercury's Contraction Much Greater Than Thought - March 16, 2014
New global imaging and topographic data from MESSENGER show that the innermost planet has contracted far more than previous estimates. The results are based on a global study of more than 5,900 geological landforms, such as curving cliff-like scarps and wrinkle ridges, that have resulted from the planet's contraction as Mercury cooled. The findings, published online today in Nature Geoscience, are key to understanding the planet's thermal, tectonic, and volcanic history, and the structure of its unusually large metallic core.

Eleventh MESSENGER Planetary Data System Release Is the Largest Yet - March 7, 2014
The Planetary Data System (PDS), which archives and distributes data from all of NASA's planetary missions, today released its eleventh batch of data collected by the MESSENGER mission. With this release, images and measurements are now available to the public for the fifth full Mercury solar day of MESSENGER orbital operations.

MESSENGER Team Receives Space Pioneer Award for Science and Engineering - March 5, 2014
The National Space Society has selected NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission as the 2014 recipient of the Space Pioneer Award in the Science and Engineering category. "With this award, NSS recognizes both the importance of the first dedicated probe to orbit Mercury and the significance of the scientific results already released," the organization said in announcing the award.

MESSENGER Surpasses 200,000 Orbital Images of Mercury - February 6, 2014
MESSENGER has now returned more than 200,000 images acquired from orbit about Mercury. The 1996 proposal for the mission promised a return of at least 1,000 images says Robert Gold, MESSENGER's Science Payload Manager. "We expected then that we would have some data compression that would probably raise the image total to somewhere near 2,000 images," says Gold, of the Johns Hopkins University Applied Physics Laboratory (APL), but scientists did not imagine then the degree to which MESSENGER would surpass that goal.

2013

MESSENGER Team Members Honored for Outstanding Accomplishments in Scientific Research and Education and Public Outreach - December 31, 2013
Three members of the MESSENGER team have been honored this month for their accomplishments in planetary research and education and public outreach. The three honorees are Catherine Johnson from the University of British Columbia (UBC) and the Planetary Science Institute, Ryan Dewey from the University of Colorado, and Brian Grigsby from Shasta High School in Redding, California.

Beatles Legend, Antiwar Author among Those Honored by Newly Named Mercury Craters - December 19, 2013
The International Astronomical Union (IAU) -- the arbiter of planetary and satellite nomenclature since its inception in 1919 -- recently approved a proposal from the MESSENGER Science Team to assign names to 10 impact craters on Mercury.

MESSENGER Celebrates 1,000 Earth Days in Orbit around Mercury - December 11, 2013
Later today, the MESSENGER spacecraft will have completed 1,000 Earth days of flight operations in orbit around Mercury. "This milestone is a testament to the outstanding work of those who designed, tested, and operated this spacecraft," says Jim McAdams of the Johns Hopkins University Applied Physics Laboratory (APL) and the lead engineer for MESSENGER's mission design team.

MESSENGER Team Presents Latest Mercury Findings at AGU Fall Meeting - December 9, 2013
Members of the MESSENGER team will present a broad range of findings from the spacecraft's orbital investigation of Mercury during the 2013 Fall Meeting of the American Geophysical Union (AGU), which takes place this week, December 9-13, in San Francisco. In 33 oral and poster presentations, team scientists will report on the analysis and interpretation of observations made by MESSENGER's instruments in the 2.5 years since the spacecraft entered orbit around Mercury in March 2011.

A Tale of Two Comets: MESSENGER Captures Images of Encke and ISON - November 25, 2013
On November 18, NASA's Mercury-orbiting MESSENGER spacecraft pointed its Mercury Dual Imaging System (MDIS) at 2P/Encke and captured this image of the comet as it sped within 2.3 million miles (3.7 million kilometers) of Mercury's surface. The next day, the probe captured this companion image of C/2012 S1 (ISON), as it cruised by Mercury at a distance of 22.5 million miles (36.2 million kilometers) on its way to its late-November closest approach to the Sun.

MESSENGER Detects Comets ISON and Encke, Prepares for Closer Encounters - November 14, 2013
NASA's Mercury-orbiting MESSENGER spacecraft has captured images of two comets -- 2P/Encke and C/2012 S1 (ISON) -- setting the stage for observations later this month when both comets will be substantially brighter and much closer to Mercury and the Sun.

1,000th Featured Image from MESSENGER Posted on the Project's Web Gallery - September 10, 2013
The MESSENGER project is celebrating the posting today of the 1,000th featured image from Mercury. The Mercury Dual Imaging System (MDIS) team has posted a new image to the MESSENGER website approximately once per business day since March 29, 2011, when the first image obtained from orbit about the innermost planet was made public.

Planetary Data System Releases MESSENGER Data from Fourth Mercury Solar Day - September 6, 2013
Data collected during MESSENGER's 19th through 24th month in orbit around Mercury were released to the public today by the Planetary Data System (PDS), an organization that archives and distributes all of NASA's planetary mission data. With this release, data are now available to the public through the fourth full Mercury solar day of MESSENGER orbital operations.

MESSENGER to Capture Images of Earth and Moon During Search for Satellites of Mercury - July 18, 2013
NASA's Mercury-orbiting MESSENGER spacecraft will capture images of Earth on July 19 and 20. The images will be taken at 7:49 a.m., 8:38 a.m. and 9:41 a.m. EDT on both days. Nearly half of the Earth, including all the Americas, Africa, and Europe, will be illuminated and facing MESSENGER, according to Hari Nair, the Johns Hopkins University Applied Physics Laboratory planetary scientist who designed and is implementing the campaign. The images on the second day will also include pictures of the Moon, where all six of the Apollo landing sites will be illuminated, 44 years to the day after Apollo 11 landed on the Moon's rocky surface.

International Astronomical Union Approves Ten New Names for Mercury Craters - June 21, 2013
The International Astronomical Union (IAU) -- the arbiter of planetary and satellite nomenclature since its inception in 1919 -- recently approved a proposal from the MESSENGER Science Team to assign names to 10 impact craters on Mercury. In keeping with the established naming theme for craters on Mercury, all of the newly designated features are named after famous deceased artists, musicians, or authors or other contributors to the humanities.

IAU Approves New Names for Ten Major Fault Scarps on Mercury - June 7, 2013
The International Astronomical Union (IAU) recently approved a proposal from the MESSENGER Science Team to assign names to 10 rupes, the long cliff-like escarpments that formed over major faults along which one large block of crust on Mercury was thrust up and over another. The IAU has been the arbiter of planetary and satellite nomenclature since its inception in 1919. In keeping with the established naming theme for rupes on Mercury, all of the newly designated features are named after ships of discovery.

MESSENGER Completes Its 2,000th Orbit of Mercury, Provides Data on Solar Magnetic Field - May 24, 2013
MESSENGER began its 2,000th orbit around Mercury earlier this week, on May 22. The spacecraft completed its primary mission on March 17, 2012, and its first extended mission on March 17, 2013. The team is awaiting word from NASA on a proposal for a second extended mission. In the meantime, instruments aboard the spacecraft continue to gather new data on Mercury and its environment.

Newly Named Mercury Craters Honor Hawaiian Guitarist, Beloved Young Adult Author - March 26, 2013
The International Astronomical Union (IAU) — the arbiter of planetary and satellite nomenclature since its inception in 1919 — recently approved a proposal from the MESSENGER Science Team to assign names to nine impact craters on Mercury. In keeping with the established naming theme for craters on Mercury, all of the newly designated features are named after famous deceased artists, musicians, or authors or other contributors to the humanities.

MESSENGER Completes Its First Extended Mission at Mercury - March 18, 2013
On March 17, 2013, MESSENGER successfully completed its year-long first extended mission in orbit about Mercury, building on the groundbreaking scientific results from its earlier primary mission. Today the team is poised to embark on a second extended mission that promises to provide new observations of Mercury's surface and interior at unprecedented spatial resolution and of the planet's dynamic magnetosphere and exosphere at high time resolution during the peak and declining phase of the current solar cycle.

Planetary Data System Releases MESSENGER Data from Third Mercury Solar Day - March 8, 2013
The Planetary Data System (PDS), which archives and distributes data from all of NASA's planetary missions, today released data collected during MESSENGER's thirteenth through eighteenth month in orbit around Mercury. With this release, images and measurements are now available to the public for the third full Mercury solar day of MESSENGER orbital operations.

MESSENGER's Discoveries Tapped as among Top Space Stories of 2012 - January 4, 2013
In 2012, the MESSENGER mission to Mercury completed its primary mission, embarked on an extended mission, saw its images and maps featured on a highly rated television show, sponsored the release of a dedicated app, and celebrated the 8th anniversary of its launch, all the while continuing to produce new findings about the planet closest to the Sun.

2012

Recently Named Mercury Craters Honor Blues Singer and Animation Pioneer - December 21, 2012
The International Astronomical Union (IAU) recently approved a proposal from the MESSENGER Science Team to assign names to nine impact craters on Mercury.

MESSENGER Finds New Evidence for Water Ice at Mercury's Poles - November 29, 2012
New observations by the MESSENGER spacecraft provide compelling support for the long-held hypothesis that Mercury harbors abundant water ice and other frozen volatile materials in its permanently shadowed polar craters.

NASA Hosts Nov. 29 News Conference about Mercury Polar Regions - November 26, 2012
WASHINGTON -- NASA will host a news conference at 2 p.m. EST on Thursday, Nov, 29, to reveal new observations from the first spacecraft to orbit the planet Mercury. The briefing will be held in the NASA Headquarters auditorium, located at 300 E St. SW in Washington.

MESSENGER Finds Unusual Groups of Ridges and Troughs on Mercury - November 15, 2012
MESSENGER has discovered assemblages of tectonic landforms unlike any previously found on Mercury or elsewhere in the Solar System. The findings are reported in a paper led by Smithsonian scientist Thomas Watters, "Extension and contraction within volcanically buried impact craters and basins on Mercury," published in the December issue of the journal Geology.

MESSENGER Mission Receives the IAA Laurels for Team Achievement Award - October 4, 2012
The International Academy of Astronautics (IAA) has awarded the 2012 Laurels for Team Achievement Award to the MESSENGER team. The award was presented September 30 at the opening ceremony of the 63rd International Astronautical Congress, which is being held this week in Naples.

MESSENGER's X-Ray Spectrometer Reveals Chemical Diversity on Mercury's Surface - September 21, 2012
New data from the X-Ray Spectrometer (XRS) on the MESSENGER spacecraft -- one of two instruments designed to measure the abundances of many key elements on Mercury -- show variations in the composition of surface material on Mercury that point to changes over time in the characteristics of volcanic eruptions on the solar system's innermost planet.

MESSENGER Data from Second Full Mercury Solar Day in Orbit Released by Planetary Data System - September 11, 2012
Late last week, the Planetary Data System (PDS) released data collected during MESSENGER's seventh through twelfth month in orbit around Mercury. PDS archives and distributes all of NASA's planetary mission data. With this release, images and measurements are now available to the public for the second full Mercury solar day of MESSENGER orbital operations.

MESSENGER Team Mourns the Loss of Neil Armstrong - August 27, 2012
The news of Neil Armstrong's death this weekend left many members of the MESSENGER team mourning his loss and reflecting on his legacy. Armstrong died on August 25, at the age of 82. He commanded the Apollo 11 spacecraft that landed on the Moon on July 20, 1969; and an estimated 600 million people witnessed, by television or radio, as he became the first man to set foot on its surface.

International Astronomical Union Approves Names for Nine Mercury Craters - August 9, 2012
The International Astronomical Union (IAU) recently approved a proposal from the MESSENGER Science Team to assign names to nine impact craters on Mercury. The IAU has been the arbiter of planetary and satellite nomenclature since its inception in 1919. In keeping with the established naming theme for craters on Mercury, all of the newly designated features are named after famous deceased artists, musicians, or authors or other contributors to the humanities.

MESSENGER Marks 8th Anniversary of Launch - August 3, 2012
The MESSENGER spacecraft launched eight years ago today — on August 3, 2004 — embarking on a six-and-a-half year journey to become the first spacecraft to orbit Mercury. The spacecraft's 4.9-billion mile (7.9-billion kilometer) cruise to history included 15 trips around the Sun, a flyby of Earth, two flybys of Venus, and three flybys of Mercury.

MESSENGER Completes Its 1,000th Orbit of Mercury - June 22, 2012
MESSENGER will complete its 1,000th orbit of the planet closest to the Sun at 11:22 p.m. EDT tonight. "Reaching this milestone is yet another testimony to the hard work and dedication of the full MESSENGER team that has designed, launched, and operated this highly successful spacecraft," says the mission trajectory lead Jim McAdams of the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.

MESSENGER Measures Waves at the Boundary of Mercury's Magnetosphere - May 22, 2012
MESSENGER scientists have concluded that waves driven by the Kelvin-Helmholtz (KH) instability play a key role in driving Mercury's magnetosphere. In a paper published recently in the Journal of Geophysical Research, the team reports on frequent detections of such waves at the outer edge of the innermost planet's magnetosphere.

MESSENGER Gains Deputy Principal Investigator - May 8, 2012
Vancouver, B.C. -- Larry Nittler, a staff scientist in the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, has been named deputy principal investigator of the MESSENGER mission. MESSENGER Principal Investigator Sean Solomon, of CIW, delivered the announcement this morning at the first plenary of the 26th meeting of the MESSENGER Science Team meeting in Vancouver, B.C.

MESSENGER's Cameras Capture 100,000th Image from Mercury Orbit - May 3, 2012
This week, MESSENGER's Mercury Dual Imaging System delivered the 100,000th image of Mercury since the spacecraft entered into orbit around the planet on March 18, 2011. The instrument — one of seven aboard the spacecraft — has globally mapped the planet in high-resolution monochrome images and in color images through eight of its color filters, uncovering a new view of Mercury and shedding light on the planet's geologic history.

Dr. Seuss, Alvin Ailey among the Names Selected for 23 Mercury Craters - April 26, 2012
The International Astronomical Union (IAU) recently approved a proposal from the MESSENGER Science Team to assign 23 new names to impact craters on Mercury. The IAU has been the arbiter of planetary and satellite nomenclature since its inception in 1919. In keeping with the established naming theme for craters on Mercury, all of the newly designated features are named after famous deceased artists, musicians, or authors.

MESSENGER Settles into Eight-Hour Orbit Around Mercury, Poised for New Discoveries - April 20, 2012
MESSENGER mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., conducted the second of two maneuvers required to reduce the spacecraft's orbital period about Mercury. The first maneuver, completed on Monday, shortened the orbital period from 11.6 to 9.1 hours and consumed the remaining oxidizer, one of two propellants that fuel the higher-efficiency large thruster. With today's maneuver, accomplished with the spacecraft's four medium-sized thrusters, MESSENGER is now in the 8-hour orbit from which it will operate for the next year.

MESSENGER Adjusts Orbit for a Closer Look at Mercury - April 16, 2012
The MESSENGER mission successfully completed the first of two maneuvers designed to reduce the spacecraft's orbital period about Mercury. This new trajectory will pave the way for more detailed measurements and targeted observations of the Sun's closest neighbor.

MESSENGER Images Debut on "The Big Bang Theory" - April 5, 2012
Tonight, images from MESSENGER's Mercury Dual Imaging System will make their debut on the CBS sitcom, "The Big Bang Theory." The award-winning comedy centers on five characters: roommates Sheldon Cooper and Leonard Hofstadter, two physicists who work at the California Institute of Technology; and Sheldon's and Leonard's equally geeky and socially awkward friends and co-workers, aerospace engineer Howard Wolowitz and astrophysicist Rajesh Koothrappali; and Penny, a blonde waitress and aspiring actress who lives across the hall.

MESSENGER App Now Available - March 23, 2012
The MESSENGER team has launched a free app that brings you inside NASA's history-making study of Mercury - the first images of the entire planet, along with the detailed data on Mercury's surface, geologic history, thin atmosphere, and active magnetosphere that MESSENGER sends back every day.

MESSENGER Provides New Look at Mercury's Landscape, Metallic Core, and Polar Shadows - March 21, 2012
MESSENGER completed its one-year primary mission on March 17. Since moving into orbit about Mercury a little over one year ago, the spacecraft has captured nearly 100,000 images and returned data that have revealed new information about the planet, including its topography, the structure of its core, and areas of permanent shadow at the poles that host the mysterious polar deposits.

MESSENGER Completes Primary Mission at Mercury, Settles in for Another Year - March 19, 2012
On March 17, 2012, MESSENGER successfully wrapped up a year-long campaign to perform the first complete reconnaissance of the geochemistry, geophysics, geologic history, atmosphere, magnetosphere, and plasma environment of the solar system's innermost planet. The following day, March 18, 2012, marked the official start of an extended phase designed to build upon those discoveries.

MESSENGER Team Delivers Data from First Full Mercury Solar Day to Planetary Data System - March 8, 2012
Data collected during MESSENGER's third through sixth month in orbit around Mercury were released to the public today by the Planetary Data System (PDS), an organization that archives and distributes all of NASA's planetary mission data. With this release, data are now available to the public for the first full Mercury solar day of MESSENGER orbital operations.

MESSENGER Modifies Orbit to Prepare for Extended Mission - March 2, 2012
MESSENGER successfully completed an orbit-correction maneuver this evening to lower its periapsis altitude - the lowest point of MESSENGER's orbit about Mercury relative to the planet's surface - from 405 to 200 kilometers (251 to 124 miles). This is the first of three planned maneuvers designed to modify the spacecraft's orbit around Mercury as science operations transition from MESSENGER's primary orbital mission to its extended mission.

Software Enables Efficient Planning of MESSENGER Observations - February 3, 2012
SciBox, a scientific planning software package, has proven critical to the success of the MESSENGER mission to Mercury. With completion of the design of all primary-mission observations -- including more than 70,000 images and millions of spectral observations -- the SciBox software tool has substantially increased, relative to original expectations, the scientific return from the first year of Mercury orbital observations. The spacecraft team is now adapting the system to develop the best plan for MESSENGER's extended mission, which begins next month.

2011

A Christmas Crater on Mercury - December 22, 2011
The crater at the center of Wednesday's MESSENGER image of the day is named Dickens, after Charles Dickens, the English novelist who lived from 1812 to 1870. Among Dickens' most famous works is A Christmas Carol, the story of miserly Ebenezer Scrooge and his tortured journey to a more humanitarian and generous nature.

MESSENGER Among Discover Magazine's Top 100 Stories of 2011 - December 16, 2011
Discover magazine has named the MESSENGER mission one of the top 100 stories of 2011. "The 100 stories here capture scientific curiosity in all its stages: provocative early results, long-sought confirmation, and many steps in the iterative process of testing theory against observation and vice versa," wrote Discover Editor-in-Chief Corey Powell in the Editor's Note for the January/February 2012 issue of the magazine.

MESSENGER Team Presents Latest Mercury Findings at AGU Fall Meeting - December 5, 2011
Members of the MESSENGER team will present a broad range of findings from the spacecraft's orbital investigation of Mercury during the 2011 Fall Meeting of the American Geophysical Union (AGU), which takes place this week, December 5-9, in San Francisco. In 63 oral and poster presentations spanning 13 technical sessions, team scientists will report on the analysis and interpretation of observations made by MESSENGER's instruments since the spacecraft entered orbit around Mercury in March 2011.

MESSENGER Recognized as "Best of What's New" by Popular Science - November 18, 2011
MESSENGER was named a winner in Popular Science magazine's 24th annual "Best of What's New" in the Aviation and Space category.

NASA Extends MESSENGER Mission - November 14, 2011
NASA has announced that it will extend the MESSENGER mission for an additional year of orbital operations at Mercury beyond the planned end of the primary mission on March 17, 2012. The MESSENGER probe became the first spacecraft to orbit the innermost planet on March 18, 2011.

MESSENGER Mission Design Lead Named American Institute of Aeronautics and Astronautics Associate Fellow - November 3, 2011
MESSENGER mission design lead engineer James McAdams has been named an Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA). To be selected for the grade of Associate Fellow an individual must be an AIAA Senior Member with at least 12 years professional experience and have been recommended by at least three AIAA members who are already Associate Fellows or Fellows.

Fourth Orbit Adjustment Stretches MESSENGER's Orbit around Mercury - October 24, 2011
The MESSENGER spacecraft successfully completed its fourth orbit-correction maneuver today to increase the period of the spacecraft's orbit around the innermost planet from 11 hours 46 minutes to a precise 12 hours.

MESSENGER Team Presents New Mercury Findings at Planetary Conference - October 5, 2011
Nantes, France—MESSENGER scientists will highlight the latest results on Mercury from MESSENGER observations obtained during the first six months (the first Mercury solar day) in orbit. These findings will be presented October 5 in 30 papers and posters as part of a special session of the joint meeting of the European Planetary Science Congress and the Division for Planetary Sciences of the American Astronomical Society in Nantes, Frances.

Orbital Observations of Mercury Reveal Flood Lavas, Hollows, and Unprecedented Surface Details - September 29, 2011
After only six months in orbit around Mercury, NASA's MESSENGER spacecraft is sending back information that has revolutionized the way scientists think about the innermost planet. Analyses of new data from the spacecraft show, among other things, new evidence that flood volcanism has been widespread on Mercury, the first close-up views of Mercury's "hollows," the first direct measurements of the chemical composition of Mercury's surface, and the first global inventory of plasma ions within Mercury's space environment.

MESSENGER Reveals New Details of Planet Mercury - September 27, 2011
NASA will host a media teleconference at 2 p.m. EDT on Thursday, September 29, to discuss new data and images from the first spacecraft to orbit Mercury. The new findings are reported in a series of seven papers published in a special section of Science magazine on September 30.

MESSENGER Team Delivers First Orbital Data to Planetary Data System - September 8, 2011
Data collected during MESSENGER's first two months in orbit around Mercury have been released to the public by the Planetary Data System (PDS), an organization that archives and distributes all of NASA's planetary mission data. Calibrated data from all seven of MESSENGER's science instruments, plus radio science data from the spacecraft telecommunications system, are included in this release.

MESSENGER Navigates Second Hot Season, Executes Third Orbit-Correction Maneuver - September 7, 2011
Today the MESSENGER spacecraft emerged unscathed from the second of four "hot seasons" expected to occur during its one-year primary mission in orbit around Mercury. Hours later, mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., successfully executed a maneuver to adjust the spacecraft's trajectory.

MESSENGER Co-Investigator Elected Fellow of the Geological Society of America - August 15, 2011
MESSENGER Co-Investigator Louise Prockter has been elected a fellow of the Geological Society of America (GSA). Established in 1888, the GSA — comprised of about 25,000 members — seeks to foster the quest for understanding the Earth, planets, and life; catalyze new scientific ways of thinking about natural systems; and support the application of geoscience knowledge and insight to human needs, aspirations, and Earth stewardship.

MESSENGER Marks Seventh Anniversary of Launch - August 3, 2011
Seven years ago, on August 3, 2004, MESSENGER left Earth aboard a three-stage Boeing Delta II rocket to begin a journey that would take it more than 15 laps through the solar system, through six planetary flybys, and ultimately into orbit around Mercury. The spacecraft has travelled 5.247 billion miles (8.445 billion kilometers) relative to the Sun, and the team is one-third of the way through the one-year science campaign to understand the innermost planet.

MESSENGER Makes Another Successful Orbit Adjustment - July 27, 2011
The MESSENGER spacecraft continued to fine-tune its orbit around Mercury yesterday afternoon when mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., successfully executed the second orbit-correction maneuver of the mission.

American Institute of Aeronautics and Astronautics Honors MESSENGER Team Leaders - July 5, 2011
The Mid-Atlantic Section of the American Institute of Aeronautics and Astronautics (AIAA) has named MESSENGER team members Peter Bedini and Eric Finnegan as Engineering Manager of the Year and Engineer of the Year, respectively, for 2011. Bedini and Finnegan, both of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., will be honored at an awards dinner later this month.

MESSENGER Science Team Member Receives NASA's Distinguished Public Service Medal - June 22, 2011
MESSENGER Co-Investigator Scott Murchie, of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., will be awarded the NASA Distinguished Public Service Medal, the highest honor that NASA bestows to an individual working outside the government. The award is granted only to individuals whose singular accomplishments contributed substantially to the NASA mission.

MESSENGER Data from Mercury Orbit Confirm Theories, Offer Surprises - June 16, 2011
After nearly three months in orbit about Mercury, MESSENGER's payload is providing a wealth of new information about the planet closest to the Sun, as well as a few surprises.

MESSENGER Adjusts Its Orbit around Mercury - June 15, 2011
The MESSENGER spacecraft successfully completed its first orbit-correction maneuver today to reset its periapsis altitude — the lowest point of MESSENGER's orbit about Mercury relative to the planet's surface — from 506 kilometers to approximately 200 kilometers.

MESSENGER Endures Its First Hot Season - June 13, 2011
Yesterday the MESSENGER spacecraft successfully completed the first of four "hot seasons" expected to occur during its one-year primary mission in orbit about Mercury. During these hot seasons, the Sun-facing side of the probe's sunshade can reach temperatures as high as 350°C.

NASA Releasing New Spacecraft Orbital Views of Mercury - June 10, 2011
NASA will host a news conference at 1 p.m. EDT on Thursday, June 16, 2011, to reveal new images and science findings from the first spacecraft to orbit Mercury. The event will be held in the NASA Headquarters auditorium located at 300 E St. SW, in Washington. NASA Television and the agency's website will broadcast the event.

100 Orbits and Counting - May 6, 2011
Later today, MESSENGER will begin its 100th orbit around Mercury. Since its insertion into orbit about the innermost planet on March 17, the spacecraft has executed nearly 2 million commands.

Measuring Mercury's Surface Composition - May 3, 2011
MESSENGER carries a Gamma-Ray Spectrometer (GRS) capable of measuring and characterizing gamma-ray emissions from the surface of Mercury. Gamma rays coming from Mercury carry information about the concentrations of elements present on its surface, and observations from the GRS are being used to determine the surface composition of the planet. Read more to see how these results will be applied to studying the formation and geologic history of Mercury.

Profiling Polar Craters with the Mercury Laser Altimeter - April 26, 2011
MESSENGER's Mercury Laser Altimeter (MLA) will measure the topography or surface relief of the northern hemisphere of Mercury. That data will be used to create topographic maps, which will help characterize the geologic history of the planet. One of the most important tasks for MLA is to measure the depths of craters that are near Mercury's north pole. In the latest "Science Highlights from Mercury's Orbit," MESSENGER's Geophysics discipline group explains why.

Mercury's Exosphere: A Brief Overview - April 19, 2011
One of the primary science goals of MESSENGER is to study Mercury's very thin atmosphere, or exosphere. Although observations of the exosphere from orbit have begun, these data must be carefully calibrated, and analysis is still underway. In the meantime, go online to Highlights-of-Mercury-Science.html for a primer on Mercury's exosphere: what it is, how we observe it, and why it is important.

MESSENGER Kicks Off Yearlong Campaign of Mercury Science - April 4, 2011
This afternoon, MESSENGER began its yearlong science campaign to understand the innermost planet. The spacecraft will fly around Mercury 700 times over the next 12 months, and its instruments will perform the first complete reconnaissance of the cratered planet's geochemistry, geophysics, geological history, atmosphere, magnetosphere, and plasma environment.

MESSENGER Sends Back First Image of Mercury from Orbit - March 29, 2011
MESSENGER has delivered its first image since entering orbit about Mercury on March 17. It was taken today at 5:20 am EDT by the Mercury Dual Imaging System as the spacecraft sailed high above Mercury's south pole, and provides a glimpse of portions of Mercury's surface not previously seen by spacecraft. The image was acquired as part of the orbital commissioning phase of the MESSENGER mission. Continuous global mapping of Mercury will begin on April 4.

NASA to Release MESSENGER's First Orbital Images Of Mercury - March 28, 2011
NASA will release the first orbital image of Mercury's surface, including previously unseen terrain, on Tuesday afternoon, March 29. Several other images will be available Wednesday, March 30, in conjunction with a media teleconference at 2 p.m. EDT to discuss these initial orbital images taken from the first spacecraft to orbit Mercury.

Spacecraft Data Confirm MESSENGER Orbit and Operation - March 21, 2011
Data from its first three days in orbit about Mercury have confirmed the initial assessment of the spacecraft team that MESSENGER is in its intended orbit and operating nominally.

MESSENGER Begins Historic Orbit around Mercury - March 17, 2011
At 9:10 p.m. EDT, engineers in the MESSENGER Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., received the anticipated radiometric signals confirming nominal burn shutdown and successful insertion of the MESSENGER probe into orbit around the planet Mercury.

MESSENGER On Autopilot for Orbit Insertion - March 16, 2011
MESSENGER is now on autopilot, faithfully executing a detailed set of instructions required to achieve its historic rendezvous with Mercury tomorrow night.

MESSENGER Primed for Mercury Orbit - March 15, 2011
After more than a dozen laps through the inner solar system and six planetary flybys, NASA's MESSENGER spacecraft will move into orbit around Mercury at around 9 p.m. EDT on March 17, 2011. The durable spacecraft — carrying seven science instruments and fortified against the blistering environs near the Sun — will be the first to orbit the innermost planet.

NASA Media Telecon Previews First Spacecraft to Orbit Mercury - March 10, 2011
NASA will host a media teleconference at 1 p.m. EDT on Tuesday, March 15, to discuss the first spacecraft to orbit Mercury.

Ten Days from Mercury Orbit Insertion - March 7, 2011
Ten days from now – on March 17 EDT – the MESSENGER spacecraft will execute a 15-minute maneuver that will place it into orbit about Mercury, making it the first craft ever to do so, and initiating a one-year science campaign to understand the innermost planet.

A Solar System Family Portrait, from the Inside Out - February 18, 2011
The MESSENGER spacecraft has captured the first portrait of our Solar System from the inside looking out. Comprised of 34 images, the mosaic provides a complement to the Solar System portrait — that one from the outside looking in — taken by Voyager 1 in 1990.

One Month Until Mercury Orbit Insertion - February 17, 2011
After more than a dozen laps through the inner solar system, NASA's MESSENGER spacecraft will move into orbit around Mercury on March 17, 2011. The durable spacecraft — carrying seven science instruments and fortified against the blistering environs near the Sun — will be the first to orbit the innermost planet.

2010

One Hundred Days until Mercury Orbit Insertion - December 7, 2010
One hundred days from now, MESSENGER will execute a 15-minute maneuver that will place the spacecraft into orbit about Mercury, making it the first craft ever to do so, and initiating a one-year science campaign to understand the innermost planet. It has already been 14 years since this mission was first proposed to NASA, more than 10 years since the project officially began, and over six years since the spacecraft was launched.

Smithsonian, SAE International Honor Papers Published by MESSENGER Team Members - October 27, 2010
The Smithsonian Institution and SAE International (formerly the Society for Automotive Engineers) have honored papers published by scientists on the MESSENGER team.

MESSENGER Team Completes Two-Week Orbital Flight Test - September 3, 2010
The MESSENGER team has just wrapped up a two-week flight test to ensure that the Mercury-bound spacecraft is ready for orbital operations. On March 18, 2011, MESSENGER will become the first spacecraft to enter into orbit about Mercury, embarking on a year-long mission to study in depth the planet closest to the Sun. The completion of this recent test provides a high-fidelity verification of the tools, processes, and procedures that are needed to conduct flight operations at Mercury.

Vulcanoid Search Continues as MESSENGER Reaches Orbital Perihelion - August 17, 2010
Today MESSENGER will pass within 0.308 astronomical units (AU) of the Sun (one AU is Earth's distance from the Sun, approximately 150 million kilometers or 93 million miles), providing MESSENGER scientists with another opportunity to search for vulcanoids. Named after the hypothetical planet Vulcan, whose existence was disproven in 1915, vulcanoids are asteroids that orbit the Sun inside the orbit of the planet Mercury.

AGU Selects MESSENGER Paper as Eos Research Spotlight - July 20, 2010
The American Geophysical Union has selected a research paper detailing observations of Mercury's magnetosphere during the probe's third flyby as a "Research Highlight" in today's issue of Eos, the AGU's weekly online and print newspaper.

MESSENGER Reveals New Information about Mercury's Exosphere, Volcanism, and Magnetic Substorms - July 15, 2010
Analysis of data from MESSENGER's third and final flyby of Mercury in September 2009 has revealed the first observations of emission from an ionized species in Mercury's exosphere, new information about magnetic substorms, and evidence of younger volcanism on the innermost planet than previously recognized. The results are reported in three papers published online on July 15 in the Science Express section of the website of Science magazine.

MESSENGER Thermal Engineer and Co-Investigator Receive Honors - May 21, 2010
Two members of the MESSENGER team have been honored by their peers. Carl Jack Ercol, the man largely responsible for ensuring that MESSENGER can withstand solar radiation up to 11 times greater than at Earth as it orbits the planet closest to the Sun, has received the 2008 SAE Arch T. Colwell Merit Award. Independently, MESSENGER Co-Investigator James W. Head, III, was awarded the Runcorn-Florensky Medal by the European Geosciences Union (EGU) at their General Assembly earlier this month.

MESSENGER Co-Investigator Receives NASA's Distinguished Service Medal - May 11, 2010
Jack Trombka, a MESSENGER Co-Investigator and member of the Science Team's Geochemistry Group, was recently awarded the NASA Distinguished Public Service Medal, NASA's highest honor. The award is granted only to individuals whose distinguished accomplishments contributed substantially to the NASA mission.

MESSENGER Team Rehearsing for Mercury Orbital Operations - April 13, 2010
It's not easy practicing for something no one has done before, but the MESSENGER team is giving it a go. Mission and science operators have wrapped up the third and fourth in a series of rehearsals for how the spacecraft will be operated once it is in orbit about Mercury.

One Year until Mercury Orbit Insertion - March 18, 2010
One year from today — starting at 12:45 a.m. UTC — MESSENGER will transition from orbiting the Sun to being the first spacecraft ever to orbit the planet Mercury.

Ten Craters on Mercury Receive New Names - March 16, 2010
The International Astronomical Union (IAU) recently approved a proposal from the MESSENGER Science Team to confer names on 10 impact craters on Mercury. The newly named craters were imaged during the mission's three flybys of Mercury in January and October 2008 and September 2009.

MESSENGER's Odometer Reading: Four Billion Miles! - February 27, 2010
Today the MESSENGER spacecraft crossed the four-billion-mile mark since its launch. The probe has completed about 81 percent of its journey toward its destination to be the first spacecraft to orbit the planet Mercury.

2009

MESSENGER Team Releases First Global Map of Mercury - December 15, 2009
NASA's MESSENGER mission team and cartographic experts from the U. S. Geological Survey have created a critical tool for planning the first orbital observations of the planet Mercury – a global mosaic of the planet that will help scientists pinpoint craters, faults, and other features for observation. The map was created from images taken during the MESSENGER spacecraft's three flybys of the planet and those of Mariner 10 in the 1970s. A presentation on the new global mosaic is being given today at the Fall Meeting of the American Geophysical Union in San Francisco.

Deep-Space Maneuver Positions MESSENGER for Mercury Orbit Insertion - November 24, 2009
The Mercury-bound MESSENGER spacecraft completed its fifth and final deep-space maneuver of the mission today, providing the expected velocity change needed to place the spacecraft on course to enter into orbit about Mercury in March 2011. A 3.3-minute firing of its bi-propellant engine provided nearly all of the probe's 177 meter per second (396 mile per hour) increase in its speed relative to the Sun.

Time Magazine Names MESSENGER One of the Best Inventions of 2009 - November 17, 2009
The MESSENGER spacecraft has been named one of Time magazine's best 50 inventions of 2009. The NASA probe, built by the Applied Physics Laboratory (APL) in Laurel, Md., came in at number 11.

MESSENGER SPACECRAFT REVEALS MORE HIDDEN TERRITORY ON MERCURY - November 3, 2009
WASHINGTON -- A NASA spacecraft's third and final flyby of the planet Mercury gives scientists, for the first time, an almost complete view of the planet's surface and provides new scientific findings about this relatively unknown planet.

MESSENGER Gains Critical Gravity Assist for Mercury Orbital Observations - September 30, 2009
MESSENGER successfully flew by Mercury yesterday, gaining a critical gravity assist that will enable it to enter orbit about Mercury in 2011 and capturing images of five percent of the planet never before seen. With more than 90 percent of the planet's surface already imaged, MESSENGER's science team had drafted an ambitious observation campaign designed to tease out additional details from features uncovered during the first two flybys. But an unexpected signal loss prior to closest approach hampered those plans.

MESSENGER Flyby of Mercury - September 29, 2009
Shortly before 5:55 p.m. EDT, MESSENGER skimmed 228 kilometers (141 miles) above the surface of Mercury in its third and final flyby of the planet. Radio signals received after the spacecraft emerged from behind the planet indicate that the spacecraft is operating nominally. Its instruments are now collecting images and other scientific measurements from the planet as it departs Mercury.

Closest Approach Tomorrow! - September 28, 2009
MESSENGER's engineering and operations teams convened at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., this morning to confirm the health and readiness of the spacecraft. "All spacecraft sub-systems and instruments reported nominal operations, indicating that MESSENGER was ready for its third encounter with Mercury," said MESSENGER Systems Engineer Eric Finnegan of APL.

MESSENGER on Mercury's Doorstep - September 26, 2009
MESSENGER is approximately two days from its third encounter with Mercury. This will be the team's last opportunity to practice at Mercury before orbit insertion, so many of the instrument command sequences have been assembled to be similar to how they will operate during the orbital phase of the mission, which begins in March 2011.

MESSENGER Prepares for Final Pass by Mercury - September 23, 2009
On September 29, 2009, the MESSENGER spacecraft will fly by Mercury for the third and final time, passing 141.7 miles above the planet's rocky surface for a final gravity assist that will enable it to enter orbit about Mercury in 2011. With more than 90 percent of the planet's surface already imaged, the team will turn its instruments during this flyby to specific features to uncover more information about the planet closest to the Sun.

Experience MESSENGER's Third Mercury Flyby Virtually - September 22, 2009
See Mercury through the "eyes" of MESSENGER's imagers with the Mercury Flyby Visualization Tool, now available here. This updated Web feature offers a unique opportunity to see simulated views of Mercury from MESSENGER's perspective, during approach, flyby, and departure, or in real-time (as the observations actually occur).

NASA TO PREVIEW MISSION'S THIRD FLIGHT PAST MERCURY - September 21, 2009
WASHINGTON -- NASA will host a media teleconference at 1 p.m. EDT on Wednesday, Sept. 23, to preview MESSENGER's third and final flyby of Mercury.

MESSENGER Team Prepares for Third Flyby, Rehearses for Orbital Operations - September 16, 2009
In less than two weeks, on September 29, MESSENGER will fly by Mercury for the third and final time, a maneuver key to placing the probe on a trajectory that will enable its March 2011 insertion into orbit about Mercury. Even as the team readies for this critical event, a parallel effort has long been underway to prepare MESSENGER for the main event.

Upcoming Mercury Encounter Presents New Opportunities for Magnetometer - August 20, 2009
On September 29, the MESSENGER spacecraft will pass by Mercury for the third time, flying 141.7 miles above the planet's rocky surface for a final gravity assist that will enable it to enter orbit about Mercury in 2011. This encounter will also provide new observational opportunities for MESSENGER's Magnetometer, designed to determine the structure and origin of Mercury's intrinsic magnetic field.

MESSENGER Mission Passes Five-Year Mark - August 3, 2009
It's been five years since MESSENGER was launched atop a Delta II rocket on August 3, 2004, and they have been busy years. It has been a long journey, says MESSENGER Mission Operations Manager Andy Calloway, "not just in distance travelled – just over 3.5 billion miles so far – but also in terms of significant milestones and accomplishments."

Sixteen Craters on Mercury Have New Names - July 15, 2009
The International Astronomical Union (IAU) recently approved a proposal from the MESSENGER Science Team to confer names on 16 impact craters on Mercury. The newly named craters were imaged during the mission's first two flybys of Mercury in January and October last year.

Three New Co-Investigators Added to MESSENGER Team - June 26, 2009
Brian Anderson, Louise Prockter, and Thomas Zurbuchen have been appointed MESSENGER Co-Investigators by NASA Science Mission Directorate Associate Administrator Edward Weiler.

MESSENGER Co-Investigator Peale Elected to National Academy of Sciences - May 5, 2009
MESSENGER Co-Investigator Stanton J. Peale, a professor emeritus renowned for his work in planetary science and astrophysics at University of California, Santa Barbara, was among the 72 new members elected to the National Academy of Sciences. The election was held April 28 during the business session of the 146th annual meeting of the Academy. Those elected bring the total number of active members to 2,150, now including four members of the MESSENGER Science Team.

MESSENGER Reveals Mercury as a Dynamic Planet - April 30, 2009
Analyses of data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft's second flyby of Mercury in October 2008 show that the planet's atmosphere, magnetosphere, and geological past are all characterized by much greater levels of activity than scientists first suspected.

MESSENGER Team to Receive National Space Club Award - April 17, 2009
The National Space Club will award the MESSENGER team its Nelson P. Jackson Aerospace Award this evening at the 52nd annual Dr. Robert H. Goddard Memorial Dinner in Washington, D.C. The award, named in honor of the National Space Club's founder and past president, is presented annually to recognize exceptional teamwork between government and industry in the missile, aircraft, and space fields.

MESSENGER Team Remembers Dr. Mario H. Acuña - March 20, 2009
Mario H. Acuña, a senior astrophysicist at NASA Goddard Space Flight Center and Co-Investigator on the MESSENGER mission, died on March 5, 2009, after a long battle against multiple myeloma. During his four decades at NASA, he played a critical role in many NASA endeavors, serving as principal investigator or key developer of experiments flown on more than 30 missions to every planet in the solar system, as well as the Sun.

MESSENGER Continues Hunt for Ever-Elusive Vulcanoids - February 9, 2009
MESSENGER reaches its orbital perihelion today and passes within 0.31 astronomical units (AU) of the Sun (one AU is nearly 150 million kilometers or 93 million miles). The mission's imaging team is taking advantage of the probe's proximity to the fiery sphere to continue their search for vulcanoids – small, rocky asteroids that have been postulated to circle the Sun in stable orbits inside the orbit of Mercury.

2008

MESSENGER Approaches Three Billion Miles, Enters Fourth Solar Conjunction - December 23, 2008
On December 26, the MESSENGER spacecraft will have traveled three billion miles since its launch, marking somewhat more than 60 percent of the probe's journey toward its destination to be inserted into orbit about Mercury.

MESSENGER Team to Present New Mercury Science Results at AGU Fall Meeting - December 12, 2008
Members of the MESSENGER science team will present a range of new findings from the spacecraft's studies of the planet Mercury during the American Geophysical Union (AGU) Fall Meeting next week in San Francisco.

MESSENGER Completes Two-Part Maneuver; Poised for Third Mercury Encounter - December 8, 2008
MESSENGER completed the second part of a two-part deep-space maneuver today, providing the remaining 10% velocity change needed to place the probe on course to fly by Mercury for the third time in September 2009.

Deep-Space Maneuver Positions MESSENGER for Third Mercury Encounter - December 4, 2008
The Mercury-bound spacecraft MESSENGER completed the first part of a two-part deep-space maneuver today, providing the expected 90% of the velocity change needed to place the spacecraft on course to fly by Mercury for the third time in September 2009. A 4.5-minute firing of its bi-propellant engine increased the probe's speed relative to the Sun by 219 meters per second (489 miles per hour) to a speed of about 30.994 kilometers per second (69,333 miles per hour).

Second Group of Mercury Craters Named - November 26, 2008
The International Astronomical Union (IAU) recently approved a proposal from the MESSENGER Science Team to name 15 craters on Mercury. All of the newly named craters were imaged during the mission's first flyby of the solar system's innermost planet in January 2008.

MESSENGER Reveals More "Hidden" Territory on Mercury - October 29, 2008
Gliding over the battered surface of Mercury for the second time this year, NASA's MESSENGER spacecraft has revealed even more previously unseen real estate on the innermost planet, sending home hundreds of photos and measurements of its surface, atmosphere, and magnetic field.

MESSENGER Gains Speed - October 15, 2008
Shortly after 4 a.m. this morning, MESSENGER reached its greatest speed relative to the Sun. The spacecraft, nearly 70% closer to the Sun than Earth, was traveling nearly 140,880 miles per hour (62.979 kilometers per second) relative to the Sun. At this speed MESSENGER would traverse the distance from Earth to Earth's Moon in only 1.7 hours!

MESSENGER Sets Record for Accuracy of Planetary Flyby - October 8, 2008
By using solar sailing – rotating the spacecraft and tilting its solar panels to use the very small pressure from sunlight to alter the spacecraft's trajectory – MESSENGER navigators have achieved a new record for the smallest miss distance between the intended and actual closest approach distance during a flyby of a planet other than Earth.

MESSENGER Reveals Mercury as Never Seen Before - October 7, 2008
When Mariner 10 flew past Mercury three times in 1974 and 1975, the probe imaged less than half the planet. In January, during MESSENGER's first flyby, its cameras returned images of about 20 percent of the planet's surface missed by Mariner 10. Yesterday, at 4:40 am EDT, MESSENGER successfully completed its second flyby of Mercury, and its cameras captured more than 1,200 high-resolution and color images of the planet – unveiling another 30 percent of Mercury's surface that had never before been seen by spacecraft.

MESSENGER Flyby of Mercury - October 6, 2008
At a little after 4:40 a.m. EDT, MESSENGER skimmed 200 kilometers (124 miles) above the surface of Mercury in the second of three flybys of the planet. Initial indications from the radio signals indicate that the spacecraft continues to operate nominally. The spacecraft is now collecting images and other scientific measurements from the planet as it departs Mercury from the illuminated side, filling in the details of much of Mercury's surface not previously viewed by spacecraft.

MESSENGER Instruments Take Aim - October 5, 2008
MESSENGER's engineering and operations teams convened at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., this afternoon to confirm the health and readiness of the spacecraft. "All spacecraft sub-systems and instruments reported nominal operations indicating that MESSENGER is ready for its second encounter with Mercury," said MESSENGER Systems Engineer Eric Finnegan of APL.

Closing in on Mercury - October 4, 2008
MESSENGER's mission design and navigation teams met today at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., to discuss the spacecraft's current trajectory to determine if a last-minute trajectory-correction maneuver would be needed.

MESSENGER Beams Back First Approach Images of Mercury - October 3, 2008
MESSENGER mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., have received the first optical navigation images from the spacecraft. "We will be taking seven additional sets over the next three days as the spacecraft approaches the planet," said APL's Eric Finnegan, the Mission Systems Engineer.

MESSENGER Returns to Mercury - October 1, 2008
On October 6, for the second time in less than a year, NASA's MESSENGER spacecraft will swoop just 200 kilometers (125 miles) above the cratered surface of Mercury, snapping hundreds of pictures and collecting a variety of other data from the planet as it gains a critical gravity assist that keeps the probe on track to become the first spacecraft ever to orbit the innermost planet beginning in March 2011.

MLA Ready to Range to Mercury's Surface - September 29, 2008
One week from today, the MESSENGER spacecraft will fly by Mercury for the second time this year. As part of the final preparations for this encounter, the Mercury Laser Altimeter (MLA) has been powered on after having been off since shortly after the first flyby at the beginning of the year. The entire MESSENGER science payload is now powered and configured to collect data during next week's encounter.

MESSENGER's Gamma-Ray Spectrometer Gears up for Mercury Flyby - September 22, 2008
Two weeks from today, the MESSENGER spacecraft will fly by Mercury for the second time. As part of the final preparations for this encounter, the Gamma-Ray Spectrometer (GRS) was placed in an "anneal mode" to prepare its detector for optimal performance during the flyby.

MESSENGER Finalizes Plans for Its Second Look at Mercury - September 12, 2008
It is now only slightly more than three weeks before the MESSENGER spacecraft flies by Mercury for the second time. At 4:40 a.m. ET on October 6, the craft will speed by the planet, passing within 125 miles (200 kilometers) and gaining a gravity assist that will tighten its orbit and keep it on its course to pass the planet one last time next year before becoming the first spacecraft ever to orbit Mercury, beginning in 2011.

MESSENGER Sails on Sun's Fire for Second Flyby of Mercury - September 5, 2008
On September 4, the MESSENGER team announced that it would not need to implement a scheduled maneuver to adjust the probe's trajectory. This is the fourth time this year that such a maneuver has been called off. The reason? A recently implemented navigational technique that makes use of solar-radiation pressure (SRP) to guide the probe has been extremely successful at maintaining MESSENGER on a trajectory that will carry it over the cratered surface of Mercury for a second time on October 6.

Sharing the Wealth: MESSENGER Team Delivers Mercury Flyby 1 Data to Planetary Data System - August 4, 2008
Data from MESSENGER's first flyby of Mercury have been released to the public by the Planetary Data System (PDS), an organization that archives and distributes all of NASA's planetary mission data.

MESSENGER Settles Old Debates and Makes New Discoveries at Mercury - July 3, 2008
Scientists have argued about the origins of Mercury's smooth plains and the source of its magnetic field for over 30 years. Now, analyses of data from the January 2008 flyby of the planet by the MESSENGER spacecraft have shown that volcanoes were involved in plains formation and suggest that its magnetic field is actively produced in the planet's core and is not a frozen relic. Scientists additionally took their first look at the chemical composition the planet's surface material. The tiny craft probed the composition of Mercury's thin atmosphere, sampled charged particles (ions) near the planet, and demonstrated new links between both sets of observations and materials on Mercury's surface. The results are reported in a series of 11 papers published in a special section of the July 4 issue of Science magazine.

NASA to Reveal New Discoveries from Mercury - July 2, 2008
NASA will host a media teleconference Thursday, July 3, at 2 p.m. EDT, to discuss analysis of data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft's flyby of Mercury earlier this year.

The Mastermind behind MESSENGER's Trajectory Honored for Efforts - May 30, 2008
Jim McAdams, the MESSENGER mission design lead engineer, was named the 2008 Engineer of the Year by the Baltimore Section, American Institute of Aeronautics and Astronautics (AIAA). Each spring, this chapter of AIAA honors those in the aerospace community who have made significant contributions during the previous year.

Mercury Features Receive New Names - April 28, 2008
The International Astronomical Union (IAU) has approved new names for features on Mercury and agreed on a new theme for fossae on the planet. These newly christened features were discovered from images taken by the MESSENGER spacecraft during its first flyby of Mercury in January.

Critical Deep-Space Maneuver Targets MESSENGER for Its Second Mercury Encounter - March 19, 2008
The MESSENGER spacecraft delivered a critical deep-space maneuver today – 64 million miles (103 million kilometers) from Earth – successfully firing its large bi-propellant engine to change the probe's trajectory and target it for its second flyby of Mercury on October 6, 2008. This was the first trajectory-correction maneuver (TCM) to test the continuous slow rotation of the spacecraft throughout the burn, essential for the March 18, 2011, Mercury orbit-insertion (MOI) maneuver.

MESSENGER Scientists to Discuss Findings From Mercury Flyby - March 7, 2008
During its January flyby of Mercury, the MESSENGER spacecraft observed swaths of the innermost planet never before seen up close. Members of the MESSENGER mission team will present findings from that historic encounter and discuss Mercury science during the 39th Lunar and Planetary Science Conference March 10-14 at the South Shore Harbour Resort and Conference Center in League City, Texas.

Making a Mosaic - March 5, 2008
During MESSENGER's flyby of Mercury on January 14, 2008, the Mercury Dual Imaging System (MDIS) acquired images to create eight different mosaics. Shown here is an image context sheet with small thumbnail versions of the MDIS Narrow Angle Camera (NAC) images that were captured as the spacecraft approached the planet and used to create a high-resolution mosaic of Mercury.

Craters in Caloris - February 27, 2008
As MESSENGER sped by Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) captured this image, which includes the edge of the planet against the blackness of space. Much of the foreground shows a portion of Caloris basin, one of the largest impact basins in the solar system.

Craters with Dark Halos on Mercury - February 21, 2008
As MESSENGER flew by Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) captured this view. Two of the larger craters in this image appear to have darkened crater rims and partial "halos" of dark material immediately surrounding the craters. Both craters appear to have nearly complete rims and interior terraced walls, suggesting that they formed more recently than the other nearby shallower craters of similar size.

One Month Ago . . . - February 14, 2008
MESSENGER's Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) captured this image during the flyby one month ago. The Sun is illuminating this region at a low angle, accentuating the modest ridges and other low topography on these nearly flat plains. Low ridges trend from the top-center of the image to the left edge (white arrows). The ghostly remains of craters are visible, filled to their rims by what may have been volcanic lavas (red arrows).

MESSENGER Team Begins Planning for Second Mercury Encounter - February 6, 2008
Little more than three weeks after MESSENGER's first historic flyby of Mercury, the team this week began mapping out its trajectory and observation plans for the probe's second pass of the planet this fall. On October 6, 2008, at 4:39 a.m. EST, the spacecraft will once again fly 200 kilometers (124 miles) above the surface of the planet.

Surprises Stream back from Mercury's MESSENGER - January 30, 2008
After a journey of more than 2.2 billion miles and three and a half years, NASA's MESSENGER spacecraft made its first flyby of Mercury just after 2 PM Eastern Standard Time on January 14, 2008. All seven scientific instruments worked flawlessly, producing a stream of surprises that is amazing and delighting the science team. The 1,213 mages conclusively show that the planet is a lot less like the Moon than many previously thought, with features unique to this innermost world. The puzzling magnetosphere appears to be very different from what Mariner 10 discovered and first sampled almost 34 years ago.

MESSENGER's Departing Shots - January 29, 2008
After MESSENGER completed its successful flyby of Mercury, the Narrow Angle Camera (NAC), part of the Mercury Dual Imaging System (MDIS), took images of the receding planet. Beginning on January 14, 2008, about 100 minutes after MESSENGER's closest pass by the surface of Mercury, until January 15, 2008, about 19 hours later, the NAC acquired one image every four minutes. In all, 288 images were snapped during this sequence; shown here are just 12 of those departing shots.

A Closer Look at the Previously Unseen Side of Mercury - January 28, 2008
Two weeks ago, on January 14, 2008, MESSENGER became the first spacecraft to see the side of Mercury shown in this image. The first image transmitted back to Earth following the flyby of Mercury, and then released to the web within hours, shows the historic first look at the previously unseen side. This image, taken by the Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS), shows a closer view of much of that territory.

Mercury's Long Cliffs - January 27, 2008
This frame, taken by the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS), shows a region of Mercury's surface previously unseen by spacecraft and a large scarp crossing vertically through the scene, on the far right of the image. This scarp is the northern continuation of the one seen in the NAC image released on January 16.

MESSENGER Looks to the North - January 26, 2008
As MESSENGER sped by Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) captured this shot looking toward Mercury's north pole.

MESSENGER's Different Views - January 25, 2008
During MESSENGER's flyby of Mercury on January 14, 2008, part of the planned sequence of observations included taking images of the same portion of Mercury's surface from five different viewing angles. The first view from this sequence was taken just after MESSENGER made its closest approach to Mercury, from a low viewing angle; an image of the first view was released on January 19. The image released here, acquired with the Wide Angle Camera (WAC) on the Mercury Dual Imaging System (MDIS), was snapped 13 minutes after MESSENGER's closest approach with Mercury.

Counting Mercury's Craters - January 24, 2008
MESSENGER team members have been identifying and measuring the impact craters on portions of Mercury that had not been previously seen by spacecraft. By counting craters on different areas of the planet's surface, a relative geologic history of the planet can be constructed, indicating which surfaces formed first and which formed later. In this image, 763 craters have been identified and measured (shown in green) along with 189 hills (shown in yellow).

MESSENGER Dances by Matisse - January 23, 2008
As MESSENGER approached Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) snapped this image of the crater Matisse.

Mercury in Color! - January 22, 2008
This visible-infrared image shows an incoming view of Mercury, about 80 minutes before MESSENGER's closest pass of the planet on January 14, 2008, from a distance of about 27,000 kilometers (17,000 miles).

Looking Toward the South Pole of Mercury - January 21, 2008
Today the MESSENGER team released this image , which shows a side of Mercury not previously seen by a spacecraft, with a view looking toward the planet's south pole.

Latest MESSENGER Images Show Fascinating Views of Mercury's Surface - January 20, 2008
As it departed Mercury on January 14, 2008, MESSENGER's Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS) acquired this view of Mercury's surface illuminated obliquely from the right by the Sun, and this frame, which records a complex history of geological evolution.

New Images Reveal Views after Closest Approach, First Mercury Laser Altimeter Results - January 19, 2008
Today the MESSENGER team released two new images. One, taken nine minutes after the spacecraft passed 200 kilometers (124 miles) above the surface of Mercury, shows the planet's surface as seen from a low viewing angle, looking over the surface and off the limb of the planet on the right side of the image. The second figure shows the distance, or range, from the spacecraft to the surface of Mercury as measured by Mercury Laser Altimeter during the flyby of Mercury.

MESSENGER's Mercury Flyby Science Data Now Safely on Earth - January 18, 2008
A day after its successful flyby of Mercury, the MESSENGER spacecraft turned toward Earth on Tuesday and began downloading the 500 megabytes of data that had been stored on the solid-state recorder during the encounter. All of those data, including 1,213 images from the Mercury Dual Imaging System (MDIS) cameras, have now been received by the Science Operations Center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.

New Images Shed Light on Mercury's Geological History, Surface Textures - January 17, 2008
Shortly following MESSENGER's closest approach to Mercury on January 14, 2008, the spacecraft's Narrow Angle Camera (NAC) on the Mercury Dual Imaging System (MDIS) instrument acquired this image as part of a mosaic that covers much of the sunlit portion of the hemisphere not viewed by Mariner 10. It provides insight into the relative timing of processes that have acted on Mercury's surface in the past. This image is one of those mosaic frames and was acquired on January 14, 2008, 18:10 UTC, when the spacecraft was about 18,000 kilometers (11,000 miles) from the surface of Mercury, about 55 minutes before MESSENGER's closest approach to the planet. It shows a variety of surface textures.

Two New Images from MESSENGER's First Flyby of Mercury - January 16, 2008
Just 21 minutes after MESSENGER's closest approach to Mercury on January 14, 2008, the Narrow Angle Camera (NAC) took this picture showing a variety of intriguing surface features, including craters as small as about 300 meters (about 300 yards) across. This image, taken 37 minutes after MESSENGER's closest approach to the planet, shows a previously unseen crater with distinctive bright rays of ejected material extending radially outward from the crater's center.

MESSENGER Reveals Mercury in New Detail - January 16, 2008
As MESSENGER approached Mercury on January 14, 2008, the spacecraft's Narrow-Angle Camera on the Mercury Dual Imaging System (MDIS) instrument captured this view of the planet's rugged, cratered landscape illuminated obliquely by the Sun.

MESSENGER's First Look at Mercury's Previously Unseen Side - January 15, 2008
When Mariner 10 flew past Mercury three times in 1974 and 1975, the same hemisphere was in sunlight during each encounter. As a consequence, Mariner 10 was able to image less than half the planet. Planetary scientists have wondered for more than 30 years about what spacecraft images might reveal about the hemisphere of Mercury that Mariner 10 never viewed.

Mercury Flyby Observations Are on the Way! - January 15, 2008
At 16:30 UTC (11:30 a.m. EST) today, MESSENGER flight controllers at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., received the first telemetry from the spacecraft following the probe's closest approach to Mercury yesterday. All spacecraft subsystems and instruments are operating normally, and telemetry data indicate that the command sequence during the flyby executed as expected.

MESSENGER Flyby of Mercury - January 14, 2008
Today, at 19:04:39 UTC (2:04:39 pm EST), MESSENGER will fly 200 kilometers (124 miles) above Mercury's surface. As the spacecraft continues to speed toward the planet, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, acquired this crescent view of Mercury.

Today MESSENGER Flies by Mercury! - January 14, 2008
Today, at 19:04:39 UTC (2:04:39 pm EST), MESSENGER will fly 200 kilometers (124 miles) above Mercury's surface. As the spacecraft continues to speed toward the planet, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, acquired this crescent view of Mercury.

MESSENGER Instruments Take Aim - January 13, 2008
MESSENGER's engineering and operations teams convened at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., early this morning to confirm the health and readiness of the spacecraft.

The Calm before Close Approach - January 12, 2008
If you look at our "Where Is MESSENGER?" page, which displays the spacecraft's trajectory status, you'll see we're right on Mercury's doorstep. MESSENGER's mission design and navigation teams at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., met yesterday to discuss the spacecraft's current trajectory to determine if a last-minute trajectory-correction maneuver would be needed.

Three Days to Mercury! - January 11, 2008
The countdown to the first flyby of Mercury by the MESSENGER spacecraft has begun. Sunday morning, MESSENGER will start recording the evidence of this historic event. At 8 a.m. EST on January 13 – 30 hours before the closest approach to Mercury – the spacecraft will turn its main antennas away from Earth and automatically begin executing the 5,000 on-board stored commands.

MESSENGER Set for Historic Mercury Flyby - January 10, 2008
NASA will return to Mercury for the first time in almost 33 years on January 14, 2008, when the MESSENGER spacecraft makes its first flyby of the Sun's closest neighbor, capturing images of large portions of the planet never before seen.

MESSENGER Team Receives First Optical Navigation Images - January 9, 2008
MESSENGER mission operators at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., have received the first eight optical navigation images from the spacecraft.

Six Days from Mercury and Counting! - January 8, 2008
The MESSENGER spacecraft continues to approach Mercury and will be less than 3 million kilometers (1.9 million miles) away from the planet at the end of today. In just six days – on January 14, 2008, at 2:04 p.m. EST – the probe will pass a mere 200 kilometers (124 miles) above Mercury's surface. Extensive scientific observations are planned during this historic flyby, the first spacecraft flyby of Mercury in more than 30 years.

MESSENGER Only One Week from Mercury - January 7, 2008
MESSENGER's mid-December trajectory correction maneuver (TCM-19) went so well that the mission design and navigation teams have decided that a TCM scheduled for January 10 will not be needed.

2007

MESSENGER ZEROS IN ON MERCURY (December 19, 2007)
MESSENGER’s nineteenth trajectory-correction maneuver (TCM-19) completed on December 19 lasted 110 seconds and adjusted the spacecraft's velocity by 1.1 meters per second (3.6 feet per second). The movement targeted the spacecraft close to the intended aim point 200 km (124 miles) above the night-side surface of Mercury for the probe's first flyby of that planet on January 14, 2008. [Read More]

MESSENGER Completes Fifty Percent of Cruise Phase (December 3, 2007)
On Friday, November 30, the MESSENGER team resumed daily contact with its Mercury-bound spacecraft. Engineers had suspended their contact schedule on November 13 as the Sun-Earth-Probe angle passed below 1° — entering a period known as solar conjunction, when the spacecraft’s trajectory moved it to the opposite side of the Sun from Earth and out of radio contact with NASA’s Deep Space Network for several weeks. [Read More]

MESSENGER Completes Fifty Percent of Cruise Phase (November 19, 2007)
On November 25, MESSENGER will have reached the halfway point in its 6.6-year cruise phase, as measured by travel time. In late January 2008 – shortly after its first flyby of Mercury – the probe’s cruise speed (relative to the Sun) will reach its highest since launch: 62.5 kilometers per second (or 140,000 miles per hour). [Read More]

NASA Selects 23 Participating Scientists for MESSENGER Mission to Mercury (November 16, 2007)
NASA has selected 23 scientists for participation in the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Mission. MESSENGER is on course to fly within 200 kilometers of Mercury on January 14, 2008 — the first probe to pass by the planet in nearly 33 years — and these Participating Scientists, along with the mission’s existing team of engineers and scientists, will play critical roles in examining the images and data gathered during before, during, and immediately following that flyby. [Read More]

Sun Cuts into MESSENGER's Dance around the Solar System (October 30, 2007)
MESSENGER entered solar conjunction on October 26, when the spacecraft’s trajectory moved it behind the Sun and out of clear view from Earth for several weeks. The team has just a limited time left before the Sun’s interference with the probe’s radio transmission severely limits communication with mission operations at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. [Read More]

Critical Deep-Space Maneuver Targets MESSENGER for Its First Mercury Encounter (October 17, 2007)
The MESSENGER spacecraft delivered a critical deep-space maneuver on Wednesday - 155 million miles (250 million kilometers) from Earth - successfully firing its large bi-propellant engine to change the probe's trajectory and target it for its first flyby of Mercury on January 14, 2008. [Read More]

MESSENGER Team Wraps Up Radio Science Test (September 27, 2007)
MESSENGER's Radio Science (RS) team recently completed a month-long orbit simulation test to measure Doppler performance using the probe's low-gain radio frequency (RF) antennas. [Read More]

MESSENGER Approaches Two Billion Miles! (September 12, 2007)
On September 13, MESSENGER will reach the two billion-mile mark, placing the spacecraft about two-fifths of the way toward its destination to orbit Mercury. [Read More]

MESSENGER TO FEEL THE HEAT DURING FIRST "HOT" PERIAPSIS (August 31, 2007)
Tomorrow, the MESSENGER probe will come within 0.33 AU of the Sun-49.67 million kilometers (or 30.86 million miles). "This is the closest we've approached the Sun during the mission so far," notes MESSENGER's Deputy Project Scientist Brian Anderson of the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. [Read More]

Happy Anniversary, MESSENGER! (August 3, 2007)
Today marks the third anniversary of MESSENGER's launch. Since its August 3, 2004, liftoff from Cape Canaveral Air Force Station, Fla., the probe has traveled nearly 1.9 billion miles on its circuitous journey from Earth to Mercury. [Read More]

SEE MESSENGER's "FAREWELL TO VENUS" VIDEO (July 23, 2007)
During its second and final close encounter with Venus on June 5, MESSENGER's wide angle camera captured a sequence of 50 images showing the planet disappearing in the distance. [Read More]

CATCH MERCURY BEFORE DAWN ON JULY 20 (July 18, 2007)
Mercury reaches its greatest western elongation Friday, and hosts of the Earth & Sky radio program will discuss this prime viewing opportunity on their show tomorrow, July 19. [Read More]

MESSENGER Team Releases First Images From Venus 2 Flyby (June 14, 2007)
The first images from MESSENGER's second flyby of Venus are in! The Mercury-bound probe flew within 338 kilometers (210 miles) of Venus on June 5, obtaining a gravity assist that shrank the radius of the probe's orbit around the Sun, pulling it closer to Mercury. But the encounter also allowed the MESSENGER team to give its two cameras, known as the Mercury Dual Imaging System (MDIS), a thorough workout. [Read More]

MESSENGER Makes Its Debut in the Smithsonian Museum (June 7, 2007)
As part of the Venus 2 flyby activities this week, a 1:5 scale model of the MESSENGER spacecraft built by carpenters at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., was hung in the Mercury exhibit in the Exploring the Planets Gallery of the Smithsonian's National Air and Space Museum (NASM) in Washington, D.C. [Read More]

MESSENGER Completes Second Flyby of Venus, Makes Its Way toward First Flyby of Mercury in 33 Years (June 5, 2007)
INASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft swung by Venus for the second time early this evening for a gravity assist that shrank the radius of its orbit around the Sun, pulling it closer to Mercury. At nearly 15,000 miles per hour, this change in MESSENGER's velocity is the largest of the mission. [Read More]

Watch Venus And Mercury This Week (And Imagine Messenger Flying By Venus) (June 1, 2007)
In the coming evenings, sky watchers can acquaint themselves with the MESSENGER spacecraft mission to Mercury. Late afternoon on Tuesday, June 5, 2007, MESSENGER will fly within about 210 miles (340 kilometers) of the surface of the planet Venus, and get a gravity kick toward its ultimate destination, the sun-baked planet Mercury. [Read More]

NASA TO PREVIEW MERCURY MISSION'S FLIGHT PAST VENUS (May 30, 2007)
WASHINGTON - NASA will host a media teleconference at 2 p.m. EDT on Monday, June 4, to preview the June 5 flyby of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft through the Venus system. The probe, the first space mission designed to orbit the planet closest to the Sun, will use Venus's gravity once again to guide it closer to Mercury's orbit. [Read More]

MESSENGER ZEROS IN ON VENUS (May 25, 2007)
The MESSENGER trajectory correction maneuver (TCM-16) completed on May 25 lasted 36 seconds and adjusted the spacecraft's velocity by 0.212 meters per second (0.696 feet per second). The movement targeted the spacecraft close to the intended aim point 337 kilometers (209 miles) above the surface of Venus for the probe's June 5 flyby of that planet. [Read More]

MESSENGER PI DISCUSSES SIGNIFICANCE OF NEWS THAT MERCURY HAS MOLTEN CORE (May 2, 2007)
MESSENGER Team Member Stan Peale was among the researchers to recently announce the discovery of strong evidence that the planet Mercury has a molten core. The finding explains a more than three-decade old planetary mystery that began with the flight of the Mariner 10 spacecraft. MESSENGER Principal Investigator Sean Solomon talks about the significance of this discovery at a Science magazine podcast, available online at http://podcasts.aaas.org/science_podcast/SciencePodcast_070504.mp3. Dr. Solomon's summary of the team's work and its importance, written as a "Perspectives" piece in the May 4, 2007, issue of Science, is available online at http://www.sciencemag.org/cgi/content/full/316/5825/702. [Read More]

MESSENGER LINES UP FOR SECOND PASS AT VENUS (May 2, 2007)
The MESSENGER trajectory correction maneuver (TCM-15) completed on April 25 lasted 140 seconds and adjusted the spacecraft's velocity by 0.568 meters per second (1.86 feet per second). One more course correction will be performed before the probe's second Venus flyby on June 5 to ensure precise targeting of the gravity assist. [Read More]

MESSENGER COMPLETES FORTY PERCENT OF CRUISE PHASE (April 2, 2007)
On March 28, MESSENGER completed 40% of its five-year cruise phase, as measured by travel time. The probe has completed one-third of its flight distance on its trip to Mercury, and its average cruise speed will continue to increase as it homes in on its ultimate target: Mercury, the closest planet to the Sun. MESSENGER's average speed will top out at a spacecraft record of close to 63 kilometers per second (141,000 miles per hour) in mid-October 2008. [Read More]

MESSENGER GEARING UP TO UNDERSTAND MERCURY'S MAGNETOSPHERE (March 19, 2007)
Among the primary questions driving NASA's MESSENGER mission to Mercury are the nature and dynamics of the planet's small, Earth-like magnetosphere and its interaction with the solar wind and Mercury's tenuous atmosphere. [Read More]

PRIMING INSTRUMENTS TO MAP MERCURY'S CRUST (February 20, 2007)
Understanding if ice exists on the surface of Mercury, and if so what types, will mark an important component of the investigations by the MESSENGER spacecraft about the origin and evolution of the solar system's inner planets. [Read More]

2006

MESSENGER LINES UP FOR ITS SECOND VENUS FLYBY (December 2, 2006)
MESSENGER's Trajectory Correction Maneuver 13 (TCM-13), its first since its maiden pass at Venus in October, was successfully executed December 2 and will help keep the spacecraft on track for its second flyby of Venus on June 5, 2007. This maneuver changed MESSENGER's velocity by 25.6 meters per second (84.1 feet per second) in a direction oriented 41.7° from the spacecraft-to-Sun direction. [Read More]

A MESSENGER SCIENCE TEAM MEMBER GETS A PREVIEW OF DISCOVERIES TO COME (November 10, 2006)
Clark R. Chapman, of the Southwest Research Institute, Boulder, Colo., had the good fortune to be in Tucson, Ariz., on November 8, when Mercury made its way across the face of the Sun in the first Mercury transit in more than three years. Chapman and his wife visited famed comet discoverer David Levy at his home in the desert near Tucson. Also attending the backyard viewing was Eli Maor, author of the book "Venus in Transit," (about the even rarer transits of Venus) and his wife.[Read More]

Upcoming Mercury/Sun Transit Whets the Appetite for MESSENGER Discoveries (November 6, 2006)
On Wednesday, November 8, the planet Mercury will make a rare trek across the face of the Sun, beginning at 2:12 p.m. EST and lasting for nearly five hours. The transit will be captured via a live Webcast featuring panel discussions with scientists, including Deborah Domingue, MESSENGER's deputy project scientist. [Read More]

MESSENGER Completes Venus Flyby (October 24, 2006)
NASA's Mercury-bound MESSENGER spacecraft came within 2,990 kilometers (1,860 miles) of the surface of Venus early this morning during its second planetary encounter. The spacecraft used the tug of the planet's gravity to change its trajectory significantly, shrinking the radius of its orbit around the Sun and bringing it closer to Mercury. [Read More]

MESSENGER Tweaks Its Route to Mercury (September 15, 2006)
The MESSENGER trajectory correction maneuver 11 (TCM 11) on September 12 lasted just under four minutes and adjusted the spacecraft's velocity by about 1.68 meters per second (5.5 feet per second). The short-duration maneuver kept MESSENGER on track for next month's Venus flyby. [Read More]

Happy Anniversary, MESSENGER! (August 3, 2006)
Today marks the second anniversary of MESSENGER's launch. "It's still more than four and a half years to Mercury Orbit Insertion in March 2011, and there are many milestones between now and then," says Dr. Sean C. Solomon, of the Carnegie Institution of Washington, who leads the mission as principal investigator. "But it's worth pausing for a few moments today to appreciate how far we've come." [Read More]

MESSENGER Flips Sunshade Toward the Sun (June 21, 2006)
On June 21, the MESSENGER spacecraft performed its final "flip" maneuver for the mission. The 16-minute maneuver, designed to keep MESSENGER operating at safe temperatures as it moves closer to the Sun, wrapped up at 9:34 a.m. EDT, with successful reacquisition of signal from MESSENGER's front-side antenna. [Read More]

MESSENGER Passes the Billion-Mile Mark! (March 24, 2006)
On March 23 MESSENGER reached the one-billion mile mark, placing the spacecraft about one-fifth of the way toward its destination to orbit Mercury. On that same day, in the early morning hours (UTC), the spacecraft's distance from the Sun was about the same as the Earth's distance to the Sun. [Read More]

MESSENGER Lines Up for Venus Flyby (February 22, 2006)
MESSENGER trajectory correction maneuver 10 (TCM 10) lasted just over two minutes and adjusted its velocity by about 1.4 meters per second (4.6 feet per second). The short-duration maneuver placed the spacecraft on track for its next major mission event: the first Venus flyby on October 24, 2006. [Read More]

2005

MESSENGER Engine Burn Puts Spacecraft on Track for Venus (December 12, 2005)
At 6:30 a.m. (EST) today NASA's Mercury-bound MESSENGER spacecraft successfully fired its large bipropellant thruster for the first time since launch, completing the first of several critical deep space maneuvers that will help the spacecraft reach Mercury orbit. [Read More]

MESSENGER Team Prepares for December Maneuver (November 11, 2005)
After successfully uploading new software to the MESSENGER spacecraft, mission controllers at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, are setting their sights on the December Deep Space Maneuver (DSM-1), when the craft's large bipropellant thruster will be fired for the first time in space on December 12. [Read More]

Movie Headlines MESSENGER Earth Flyby Gallery (August 26, 2005)
The pictures from MESSENGER's Aug. 2 flyby of Earth are in - and spectacular. The collection includes "natural" color and infrared views of North and South America; a peek at the Galapagos Islands through a break in the clouds; and a movie of the rotating Earth, taken as MESSENGER sped away from its home planet. [Read More]

MESSENGER Completes Successful Earth Swingby (August 2, 2005)
NASA's MESSENGER spacecraft, headed toward the first study of Mercury from orbit, swung by its home planet today for a gravity assist that propelled it deeper into the inner solar system. [Read More]

MESSENGER Lines Up for Earth Swingby (July 21, 2005)
MESSENGER's fifth trajectory correction maneuver lasted just 23 seconds and adjusted its velocity by less than half-a-foot per second. But the fleeting maneuver went a long way in keeping the spacecraft on track for the upcoming gravity-assist flyby of Earth. [Read More]

MESSENGER Executes Successful Flyby Test (July 5, 2005)
The MESSENGER team successfully tested the spacecraft and instrument commands planned for next month's flyby of Earth - a key step in preparing the final sequences for this critical maneuver. [Read More]

MESSENGER Sets Course for Earth Flyby (June 23, 2005)
A short maneuver kept MESSENGER on track for its Aug. 2 flyby of Earth - the major gravity assist that starts the next leg of the spacecraft's journey toward Mercury. [Read More]

MESSENGER Peeks at Earth (May 31, 2005)
The MESSENGER spacecraft - less than three months from the Earth flyby that will slingshot it toward the inner solar system - successfully tested its main camera by snapping distant approach shots of Earth and the Moon. [Read More]

MESSENGER Antenna Gains from Teamwork (April 27, 2005)
What happens when teams of varying expertise put their heads together to develop and test a unique, mission critical system? You can make deep space communications history -- like MESSENGER did when it launched with electronically-steered phased array antennas that will allow scientists to send back twice as much data about Mercury than originally envisioned. [Read More]

An Energetic Checkout (April 18, 2005)
The MESSENGER team continues to check out the spacecraft's science payload - including a full commissioning of the Energetic Particle and Plasma Spectrometer (EPPS) instrument - and prepare for additional instrument operations in the weeks ahead. [Read More]

MESSENGER Deploys Magnetometer, Flips Sunshade Toward Sun (March 8, 2005)
MESSENGER is now cruising with its sunshade facing the Sun and its Magnetometer boom extended, after a pair of long-planned and successful operations. [Read More]

Planning for the Flip (March 1, 2005)
Preparations and testing continue for the scheduled March 8 spacecraft "flip," which will point MESSENGER's sunshade toward the Sun. Shortly after the flip, MESSENGER will deploy the boom for the Magnetometer instrument. [Read More]

Staring at a Supernova (February 14, 2005)
MESSENGER's X-Ray Spectrometer underwent calibrations last week, spending five days "looking" at one of the stronger x-ray sources in the sky, the supernova remnant Cassiopeia A. The test gave the team its best look yet at the instrument's detectors. [Read More]

Heading Back (February 7, 2005)
Last week the MESSENGER spacecraft reached "local max" -- its farthest distance from home before starting back toward Earth for the gravity-assist flyby on Aug. 2. [Read More]

Planning Ahead (January 31, 2005)
MESSENGER is in good health and its systems are operating normally. Last week the Mission Operations team at the Johns Hopkins University Applied Physics Laboratory continued working on software upgrades for MESSENGER's flight and ground systems and planning for upcoming flight activities. [Read More]

Camera Check (January 17, 2005) Last week, MESSENGER's science, engineering and mission operations teams successfully conducted the second absolute radiometric calibration for the Mercury Dual Imaging System. [Read More]

Looking Ahead (January 10, 2005)
The MESSENGER spacecraft and science teams are looking ahead to several key events in 2005. [Read More]

2004

Power Play (December 20, 2004)
Mission operators conducted a peak power test, which determines exactly how much power MESSENGER's solar arrays can produce at a given time and position. Spacecraft team members use this information to make sure the arrays are in good condition and to plan instrument operations, among other activities. [Read More]

Star Gazing (December 13, 2004)
MESSENGER conducts a star search to make sure its Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument is functioning as designed. [Read More]

Onboard Computing (December 06, 2004)
The MESSENGER operations team has switched from commanding the spacecraft in real time to using command sequences stored in its onboard computer. [Read More]

Three for Three (November 18, 2004)
MESSENGER completed its third trajectory correction maneuver since launch - and its last of 2004 - trimming its speed and tweaking its course toward the Earth flyby next August. [Read More]

Maneuver Keeps MESSENGER on Track (September 24, 2004)
MESSENGER marked its 52nd day of flight operations with a burst from its thrusters, completing a maneuver today that kept it on course for next summer's Earth flyby. [Read More]

Blazing Thrusters (August 24, 2004)
MESSENGER's Mission Operations team successfully completes mission's first trajectory correction maneuver. [Read More]

Checkout Time (August 10, 2004)
With a successful launch behind them and a long cruise ahead, MESSENGER mission operators are checking out the systems on the Mercury-bound spacecraft. [Read More]

We Have Liftoff! (August 3, 2004)
MESSENGER is away! The spacecraft was launched from Launch Pad 17B at Cape Canaveral Air Force Station, Fla., at 2:15:56 a.m. EDT aboard a three-stage Boeing Delta II rocket. [Read More]

Launch Reset for August 3 (August 2, 2004)
MESSENGER's launch has been rescheduled for August 3 at 2:15:22 am EDT, due to weather concerns.

Going, Going, Gone! (July 27, 2004)
Our Webcam captured MESSENGER's final moments at the Astrotech Space Operations facility, where the team processed and tested the Mercury-bound spacecraft before sending it to the launch pad. [Read More]

MESSENGER on the Launch Pad (July 21, 2004)
Riding atop its spacecraft transporter, MESSENGER arrived at Pad 17-B on Cape Canaveral Air Force Station early this morning and was lifted atop the Boeing Delta II rocket. [Read More]

Next Stop: The Launch Pad (July 19, 2004)
MESSENGER is now firmly attached to the third stage of its Delta II launch vehicle. Next, the team will prepare the spacecraft for the slow drive to the launch pad. [Read More]

NASA Sending a MESSENGER to Mercury (July 15, 2004)
NASA's first trip to Mercury in 30 years - and the closest look ever at the innermost planet - starts August 2 with the predawn launch of the MESSENGER spacecraft from Cape Canaveral Air Force Station, Fla. [Read More]

Fill ‘er Up! (July 9, 2004)
Even spacecraft have to stop at the pump before a long journey! Last week the engineering team loaded propellant onto the spacecraft – this is the fuel and oxidizer MESSENGER needs for its thrusters. [Read More]

Upon Reflection... (July 2, 2004)
The drive to launch continues! MESSENGER's custom-developed, mirrored solar panels - which will provide all the spacecraft's power during its long voyage to and orbit around Mercury - are among the last major components to be attached before the spacecraft is moved to the Delta II launch vehicle. [Read More]

MESSENGER Launch Set for August 2 (June 29, 2004)
With the successful launch of the Air Force Delta/GPS mission last week, MESSENGER's launch has been rescheduled and is now targeted to occur Aug. 2. While the previous launch date of July 30 may have been achievable, the additional margin now being built into the schedule will provide greater confidence in meeting this new launch date. [Read More]

Vaughn Named Engineer of Year (June 29, 2004)
MESSENGER team member Robin Vaughan has been named Engineer of the Year by the Baltimore chapter of the American Institute of Aeronautics and Astronautics (AIAA). The award cites her work as MESSENGER's lead guidance and control engineer. [Read More]

Closing Out (June 22, 2004)
Adjusting thermal insulation blankets, adding thermal mass and applying Teflon tape are on the list of closeout activities as the MESSENGER team readies the spacecraft for launch. [Read More]

On Again (June 11, 2004)
MESSENGER's flight battery returns to the spacecraft, as the pace of launch preparations picks up at the Astrotech operations facility near Kennedy Space Center. [Read More]

Awaiting the Big Push (June 3, 2004)
With MESSENGER in the late testing stages, launch preparations will soon begin. A few days before MESSENGER is mated to the upper stage of the Delta II launch vehicle, the team will fill the spacecraft's propellant and pressurant tanks. [Read More]

Taking Commands (May 21, 2004)
While MESSENGER sits quietly in a clean room, there's a flurry of activity back in the Mission Operations Center, where the MESSENGER team is testing and finalizing software for the spacecraft and ground-support systems. [Read More]

Monthly Cleaning (May 7, 2004)
Despite strict measures to keep dust out of MESSENGER's assembly and testing areas, the team occasionally needs to roll up its sleeves, plug in the black lights and clean the spacecraft by hand.[Read More]

MESSENGER Team Member Wins Presidential Award (May 5, 2004)
Thomas Zurbuchen, an associate professor at the University of Michigan who helped develop MESSENGER's Fast Imaging Plasma Spectrometer and will lead a major effort to analyze and interpret the data from that sensor, has received a Presidential Early Career for Scientists and Engineers award for his work on a solar wind study. [Read More]

Clear Connection (April 29, 2004)
The team successfully tests MESSENGER's radio system links through the Deep Space Network. [Read More]

Undercover Operations (April 23, 2004)
Watch the Webcam these days and things might look a bit slow around MESSENGER, but the spacecraft's insides are hard at work! Most of the activity is taking place in the MESSENGER Mission Operations Center, where the team is running autonomy tests and mission simulations. [Read More]

Communications from the Cape (April 15, 2004)
Launch preparations continue at the Astrotech Space Operations facilities near Kennedy Space Center, where the MESSENGER team is testing the spacecraft's communications and autonomy systems. [Read More]

The Layered Look (April 9, 2004)
When it comes to fending off the excess heat at Mercury -- but staying warm when operating closer to Earth -- MESSENGER takes a multilayered approach. [Read More]

On and Off (April 2, 2004)
With pre-launch preparations under way, MESSENGER's move to a summer launch schedule required some flexibility from the spacecraft team in Florida. [Read More]

MESSENGER Launch Rescheduled (March 24, 2004)
MESSENGER’s new 15-day launch period extends from July 30-August 13, 2004. After a swingby of Earth and multiple passes of Venus and Mercury, the spacecraft is set to begin orbiting Mercury in March 2011. [Read More]

MESSENGER's Lifeline (March 18, 2004)
MESSENGER's antennas will provide the critical link back home during the spacecraft's mission to Mercury. Get a close up look at these key devices in this week's annotated Webcam image. [Read More]

Another Big Move! (March 12, 2004)
The team is now processing MESSENGER for launch near Kennedy Space Center in Florida - but the Webcam took one last look at spacecraft in Maryland before the successful move from NASA Goddard Space Flight Center. [Read More]

MESSENGER Arrives (March 10, 2004)
MESSENGER has arrived in Florida after being shipped from NASA's Goddard Space Flight Center. The spacecraft arrived at the Astrotech Space Operations processing facilities near Kennedy Space Center, where it was offloaded and taken into a high bay clean room. [Read More]

MESSENGER Ships to the Cape (March 9, 2004)
The MESSENGER spacecraft left home in Maryland today for Kennedy Space Center/Cape Canaveral, Florida, site of its scheduled May launch to Mercury. [Read More]

Out of the Oven (March 5, 2004)
MESSENGER is now well done! The spacecraft is out of the thermal vacuum chamber at NASA Goddard Space Flight Center after a series of rigorous environmental tests. See where it's "camping out" now in this week's Webcam image. [Read More]

Home Stretch (February 23, 2004)
Assembly of the MESSENGER spacecraft started early in 2003 when the integrated structure and propulsion system was delivered to the Applied Physics Laboratory. Since then the spacecraft has come together before our eyes, thanks to the live MESSENGER Webcam, weekly images and a collection of time-lapse movies. [Read More]

The Camera Takes Aim (February 11, 2004)
MESSENGER's onboard camera  steps in for the Webcam this week,  providing an image from a recent alignment check at Goddard Space Flight Center. Careful alignment of each instrument is crucial for planning future science observations, but especially for the camera, which operators will also use for navigation during MESSENGER's flight. [Read More]

MESSENGER's Heartbeat (February 6, 2004)
With MESSENGER sealed in a thermal vacuum  test chamber, the team "watches" the spacecraft through specialized test devices. See what engineers use to check MESSENGER's vital signs in this week's annotated Webcam image. [Read More]

MESSENGER Roast (January 30, 2004)
Over the past few days MESSENGER's ceramic-fabric sunshade has roasted in a test chamber, proving its ability to weather the extreme environment at Mercury. Check out the work in week's annotated Webcam image. [Read More]

MESSENGER Uncovered (January 22, 2004)
The sunshade comes off and temperature sensors go on, as the team prepares MESSENGER for a month in a simulated space environment. Check out the work in week's annotated Webcam image. [Read More]

Spin Cycle (January 15, 2004)
Making sure their spacecraft will fly straight after launch, engineers take MESSENGER for a spin in the latest Webcam image. [Read More]

MESSENGER Gets an Earful (January 7, 2004)
With the help of some powerful speakers and a rumbling roar, the MESSENGER team tests the spacecraft for a loud and rough rocket ride in our latest. Check out the latest Webcam image for details. [Read More]

2003

Keeping MESSENGER Cool (December 30, 2003)
How does a Mercury orbiter keep its cool? MESSENGER's ceramic-fabric sunshade, recently installed on the spacecraft, has a lot to do with it. Check out the latest Webcam image for details. [Read More]

MESSENGER Prepped for Prelaunch Tests (December 19, 2003)
MESSENGER heads to NASA's Goddard Space Flight Center for the next round of space-environment tests. [Read More]

MESSENGER on the Move! (December 19, 2003)
Check out the work that led up to the big move in the latest in this week's annotated Webcam image. [Read More]

Meeting a Powerful Challenge (December 12, 2003)
Wrapping up a successful weekend, the MESSENGER team installed and tested the custom-developed solar panels that will provide power to the spacecraft during the journey to and orbit around Mercury. Check out the activity in this week's annotated Webcam image. [Read More]

In the Swing (December 5, 2003)
This week's annotated Webcam image shows the "balancing" act the team conducted to measure the magnetic field coming from MESSENGER - and gather information critical to making sure the spacecraft gets an accurate reading of Mercury's magnetic field from orbit. [Read More]

Taking Charge (November 26, 2003)
Through the next several months of operational and environmental testing, MESSENGER's spare flight battery will provide power to the spacecraft's systems and instruments. Watch the team install the battery in this week's annotated Webcam image. [Read More]

Test Fire (November 19, 2003)
MESSENGER's propulsion system was a "thrust" of the spacecraft's latest functional tests. See how it made the grade in this week's annotated Webcam image. [Read More]

Up or Down? (November 13, 2003)
Are MESSENGER's subsystems speaking the same language? This week's annotated Webcam image shows how the spacecraft team checks this vital operation. [Read More]

Cosmic Collisions (November 6, 2003)
MESSENGER's Neutron Spectrometer will help scientists unravel Mercury's early history by providing compositional information about the planet's crust. See how the team tested this critical device in this week's annotated Webcam image. [Read More]

Square and Plumb (October 31, 2003)
Just like a house needs straight walls and correct angles, it is critical that MESSENGER's components are carefully aligned during assembly. Read about the spacecraft's recent alignment check in this week's annotated Webcam image. [Read More]

Simulating Space (October 24, 2003)
How do you copy the magnetic field around Mercury - and make sure MESSENGER will be able to measure it? Read about one way the MESSENGER team simulates the space environment in this week's annotated Webcam image. [Read More]

Status Report: MESSENGER Aims for May Launch Date (October 21, 2003)
Gaining additional time to integrate and test its spacecraft, the MESSENGER team is working toward a launch in May 2004. [Read More]

MESSENGER Phones Home (October 16, 2003)
To make sure it can send data back from space - and receive commands from the operations team on Earth - MESSENGER's communications system spent last week "talking" through simulated Deep Space Network antennas. See this week's annotated Webcam image for more on these critical tests. [Read More]

An Instrumental Milestone (October 7, 2003)
On October 3, the Gamma-Ray Spectrometer Pre-Amp Box was re-installed on MESSENGER - marking the first time all seven science instruments were completely installed on the spacecraft! Read about it in this week's annotated Webcam image. [Read More]

Portable Sun (October 3, 2003)
To make sure its protective sunshade faces the right direction, MESSENGER will have to keep its electronic eyes on the Sun at all times. See how the team tested MESSENGER's Sun Sensors in this week's annotated Webcam. [Read More]

A High-Tech Rain Coat (September 24, 2003)
Spacecraft designers usually have to worry about solar storms, micrometeorites and extreme temperatures. Last week the MESSENGER team prepared to protect the spacecraft from an entirely different sort of storm - Hurricane Isabel. [Read More]

Scanning the Stars (September 17, 2003)
Like the ancient mariners, the MESSENGER spacecraft will keep track of its position by checking the location of stars and the Sun. Check out this week's annotated Webcam image for details. [Read More]

MESSENGER Weighs In (September 4, 2003)
Controlling a spacecraft’s weight is a challenge for any design and assembly team. Check this week’s annotated Webcam image to see how MESSENGER recently tipped the scales. [Read More]

MESSENGER's Eyes (August 28, 2003)
The MESSENGER assembly team met another milestone with final installation of the Mercury Dual Imaging System, known as MDIS. Check out this week's annotated Webcam image for details. [Read More]

A Clean Purge (August 19, 2003)
MESSENGER's scientific instruments are bathed in a steady flow of extremely pure nitrogen - known as a "purge" - which keeps dust and moisture away from these sensitive components. Read about it in this week's [Read More]

Spacecraft in a Suitcase (August 14, 2003)
It looks more like a suitcase than a satellite, but the spacecraft simulator allows engineers to test equipment before they connect it to the actual MESSENGER. See this week's annotated Webcam image [Read More]

A Powerful Move Forward (August 11, 2003)
MESSENGER's propulsion system is now in place and has passed critical tests as work moves forward on spacecraft assembly. See this week's annotated Webcam image [Read More]

Eyeing the Field (August 1, 2003)
The tool designed to answer key questions about Mercury's magnetic field -- the MESSENGER Magnetometer instrument -- is coming together on the spacecraft. See this week's annotated Webcam image [Read More]

Schedule Drivers (July 25, 2003)
Check out this week's annotated image to see how the MESSENGER team is preparing to install the Mercury Laser Altimeter instrument on the spacecraft. [Read More]

MESSENGER's Laser in Line for Installation (July 18, 2003)
Check out this week's annotated image to see how the MESSENGER team is preparing to install the Mercury Laser Altimeter instrument on the spacecraft. [Read More]

A Powerful Drive (July 10, 2003)
What drives MESSENGER's solar panels? Find out in this week's annotated Webcam image.MESSENGER Webcam image. [Read More]

Heating Up (June 27, 2003)
Why put heaters on a spacecraft bound for the Sun's closest planetary neighbor? Find out in this week's annotated MESSENGER Webcam image. [Read More]

MESSENGER Puts on a MASCS (June 5, 2003)
With several bolts and a few adjustments, MESSENGER team members at the Johns Hopkins Applied Physics Laboratory (APL) reached a milestone last weekend when they installed the first science instrument on NASA's Mercury-bound spacecraft. Read the story, check out this week's annotated image or watch this time-lapse movie of that day's work! [Read More]

Keeping Clean in the Cleanroom (May 28, 2003)
The MESSENGER team takes regular steps to clean and protect the spacecraft's sensitive components. Check out this week's annotated MESSENGER image for an explanation. [Read More]

Testing Time (May 20, 2003)
They might only be temporary, but engineering models play a critical role in testing a spacecraft. Check out this week's annotated MESSENGER image for an explanation. [Read More]

The 2003 Mercury Transit (May 7, 2003)
On May 7, skywatchers worldwide peered through telescopes and watched on the Web as Mercury crossed the face of the Sun - a rare event known as a "transit."

MESSENGER Assembly Under Way (March 12, 2003)
Start the countdown clock at one year: the effort to assemble and test the MESSENGER spacecraft, set to embark next March on an historic voyage to the innermost planet, is under way. [Read More]

MESSENGER's Propulsion System Is a Go (January 31, 2003)
The propulsion system designed to carry MESSENGER through a six-year, nearly 4-billion mile trip to and around Mercury is complete, marking a major step in the mission's development. [Read More]

2002 & older

MESSENGER Cleared to Build Spacecraft (March 29, 2002)
MESSENGER took a big step toward its scheduled March 2004 launch recently when the project received approval to start building the spacecraft and scientific instruments. [Read More]

NASA Gives Official Nod to First Mercury Orbiter (June 7, 2001)
NASA has given MESSENGER the go-ahead to move into full-scale mission development — setting up the first trip to the sun’s closest neighbor in more than a generation. [Read More] [NASA release]