QUICKTIME

MLA Measurements
The Mercury Laser Altimeter (MLA) is shown ranging to Mercury’s surface from orbit. In this animation, yellow flashes represent near-infrared laser pulses that can reflect off terrain in shadow as well as in sunlight. Using about as much power as a flashlight, the MLA instrument can range eight times a second to targets at distances as far as that from Washington, D.C., to Ottawa, Canada (~800 km), St. Louis, Missouri, or Orlando, Florida (~1200 km). The laser pulse returns from the surface in less than one hundredth of a second. This time interval can be measured to a precision equivalent to a hand’s breadth uncertainly in distance. Measurements are assembled from individual profiles to produce a terrain model such as the one shown here.
Credit: Scientific Visualization Studio, NASA Goddard Space Flight Center.

MLA in Operation
Schematic illustration of the operation of MESSENGER’s Mercury Laser Altimeter (MLA). (140 MB or 28 MB) MLA ranges to Mercury whenever the spacecraft is within 1,800 km of the surface. Eight times per second, MLA’s laser emits a short (5 ns) pulse, which propagates along the laser transmitter’s line of sight to the surface, where a fraction of the pulse energy is reflected from the surface and propagates back to MLA’s four receiver telescopes. The time of flight of the laser pulse provides the distance to the portion of the surface from which signal was reflected. Knowledge of the spacecraft’s position then allows recovery of the elevation of the reflection point.

GRNS in Operation
Schematic illustration of the operation of MESSENGER's Gamma-ray and Neutron Spectrometer (GRNS). (12.8 MB or 3.4 MB) Galactic cosmic rays interact with the surface of Mercury to a depth of tens of centimeters, producing high-energy (“fast”) neutrons. These neutrons further interact with surface material, resulting in the emission of gamma-rays with energies characteristic of the emitting elements and low-energy (“slow”) neutrons. Naturally occurring radioactive elements such as potassium (K), thorium (Th), and uranium (U) also emit gamma-rays. Detection of the gamma-rays and neutrons by GRNS allows determination of the chemical composition of the surface.

XRS in Operation
Schematic illustration of the operation of MESSENGER's X-ray Spectrometer (XRS). (5.8 MB or 2.4 MB) When X-rays emitted from the Sun’s corona strike the planet, they can induce X-ray fluorescence from atoms at the surface. Detection of these fluorescent X-rays by the XRS allows determination of the surface chemical composition.

Launch to Orbit
View MESSENGER’s journey (40 MB or 1.7 MB) from launch on August 3, 2004, through Earth, Venus, and Mercury flybys, to Mercury arrival on March 18, 2011. Check out the relative motions of Earth, Venus, Mercury and the MESSENGER spacecraft trajectory, nearly 16 spacecraft orbits around the Sun, and the orbits of Earth, Venus and Mercury in the plane of Earth’s orbit. Use the timeline at the bottom to track the spacecraft’s progress from launch to Mercury orbit insertion.

View the same journey but from a different perspective, with Earth's orbital motion frozen (75.5 MB or 6.6 MB). In this animation, while the spacecraft is in the "solar conjunction" region (shown as a yellow-shaded region in the upper left), interference from the Sun can reduce or prevent communication with the spacecraft.

Launch
View Earth from MESSENGER (13.2 MB or 5.8 MB) or see the spacecraft’s path from high above Asia (5.6 MB or 1.6 MB) beginning at launch on August 3, 2004. The view from MESSENGER features night lights of Florida and a close-up view of southern Africa.

Earth Flyby
Ride along with MESSENGER (17.9 MB or 6.0 MB) or watch from high above northern Asia (8.7 MB or 3.8 MB) as the spacecraft flies by Earth on August 2, 2005. The view from above northern Asia depicts the spacecraft flying above, not through, Earth’s shadow.

Venus Flyby 1
Soar over Venus’ cloud deck on October 24, 2006. Two views show the encounter from MESSENGER’s perspective (8.0 MB or 4.2 MB) or from above Venus’ north pole (7.2 MB or 3.9 MB).

Venus Flyby 1 - additional views
The MESSENGER flyby trajectory and Venus Express orbit around Venus (7.6 MB) have tick marks every 30 minutes and a line-of-sight link (no communication is possible) between each spacecraft. The marker for MESSENGER changes color during eclipse, when Venus blocks sunlight from reaching the spacecraft. Venus Express orbit data courtesy of Trevor Morley of the European Space Agency. View the surface features of Venus that MESSENGER will fly over (45.1 MB). The red line with time ticks every two minutes shows the surface directly below the spacecraft. Thick clouds above Venus and limited spacecraft activity during the flyby will prevent the spacecraft's instruments from observing the planet's surface. Topographic maps courtesy of Ralph Aeschliman.

Venus Flyby 2
Follow MESSENGER’s second trip over Venus on June 5, 2007, choosing from MESSENGER’s view (7.6 MB or 4.9 MB) or from above Venus' north pole (6.7 MB or 3.7 MB).

As the MESSENGER spacecraft approaches the brightly illuminated Venus it will begin a carefully planned sequence of science observations that are designed to practice activities planned seven months later at the first flyby of Mercury. This animation shows the approximate spacecraft orientation with Venus in the background from one hour before closest approach to one hour after the 338 kilometer altitude closest approach. (8.4MB)

Venus Flyby 2 - additional views
The MESSENGER flyby trajectory and Venus Express orbit around Venus are shown in this animation (21.2 MB), with tick marks every 30 minutes and a line-of-sight path (through no communication is possible) between each spacecraft. Notice how the MESSENGER spacecraft model becomes dimmer and how the line-of-sight between MESSENGER and Venus Express disappears as the spacecraft passes through solar eclipse (the shadow of Venus). Preliminary planned movements of the MESSENGER spacecraft also appear in the animations. The animations show the best publicly available predicted position and orbit orientation (not the planned spacecraft orientation) of the Venus Express spacecraft.

View the surface features of Venus that MESSENGER will fly over (11.2 MB). The red line with time ticks every two minutes shows the surface directly below the spacecraft. Thick clouds above Venus and spacecraft pointing limits will prevent many of the spacecraft's science instruments from observing the surface of Venus. Topographic maps courtesy of Ralph Aeschliman.

Venus Flyby 2 Instrument Operations
This animation (6.2MB or 37.4MB) shows the planet Venus with its center fixed in the center of the field of view as MESSENGER flies by the planet obtaining a gravity assist. The maneuvers shown for the spacecraft correspond to the programmed pointing and data collection sequences implemented in the actual flyby. Large rectangular fields of view indicate imaging with the Wide Angle Camera of the Mercury Dual Imaging System (MDIS); smaller fields of view correspond to images made with the Narrow Angle Camera of the same instrument. Other remote-sensing instrument footprints are shown as well, noted with labels in the animation.

Mercury Flyby 1
On January 14, 2008, MESSENGER flies over the eastern side of Mercury’s never-before-imaged hemisphere. Mariner 10 images are projected onto the globe of Mercury in these animations. See the encounter from MESSENGER (9.28 MB or 4.70 MB) and over Mercury's north pole (3.00 MB or 1.82 MB).

Mercury Flyby 1 Instrument Operations
This animation (10.4 MB or 84.2 MB) shows the planet Mercury as MESSENGER flies by the planet for the first time during the mission. The maneuvers shown for the spacecraft correspond to the programmed pointing and data collection sequences planned for the flyby. Large rectangular fields of view indicate imaging with the Wide Angle Camera of the Mercury Dual Imaging System (MDIS); smaller fields of view correspond to images made with the Narrow Angle Camera of the same instrument. Other remote-sensing instrument footprints are shown as well with labels describing the measurements made.

The animation is compressed by about 90:1 (1 second of animation is about 90 seconds of real time). The animation begins at January 14, 2008, when MESSENGER is about 2 hours and 40 minutes before closest approach and about 57,000 km from the center of the planet. The animation ends on January 14, 2008, about 1 hour and 45 minutes after closest approach and about 38,000 km from the center of the planet.

Mercury Flyby 1 - Ground Track views
This animation (21.9 MB) shows the spacecraft's ground track on Mercury's surface with time ticks every two minutes and labeled latitude and longitude lines. The latitude, longitude, and altitude of MESSENGER are shown every 10 seconds within one hour of closest approach on January 14, 2008. The view of Mercury combines Mariner 10 spacecraft images and Arecibo radar images.

View the track below MESSENGER (15 MB) while viewing a projection of the entire surface of Mercury. A label shows the extent of Arecibo radar images. All other longitudes display Mariner 10 images of the surface. The "closest point" marker indicates the point on Mercury's surface below MESSENGER at closest approach. The animation covers the period within three hours of closest approach.

Mercury Flyby 2
On October 6, 2008, MESSENGER zips past the western end of Mercury’s “unseen” hemisphere. Images from MESSENGER's first flyby of Mercury, Mariner 10 images, and Arecibo radar images make up the globe of Mercury. Watch the encounter from MESSENGER (22.2 MB or 13.6 MB) and over Mercury's north pole (20.4 MB or 12.1 MB).

Mercury Flyby 2 Instrument Operations
This animation (17.8 MB or 98.3 MB) shows the instrument observations planned to execute during MESSENGER's second flyby of Mercury on October 6, 2008. (Large version without labels: 95 MB)

Mercury Flyby 2 - Ground Track views
This animation (28.3 MB) shows the spacecraft's ground track on Mercury's surface with time ticks every two minutes and labeled latitude and longitude lines. The latitude, longitude, and altitude of MESSENGER are shown every 10 seconds within one hour of closest approach on October 6, 2008. The view of Mercury combines Mariner 10 spacecraft images and surface feature names, MESSENGER Mercury flyby 1 images, and Arecibo radar images.

View the track below MESSENGER (126 MB) while viewing a projection of the entire surface of Mercury. A label shows the extent of poor-resolution Arecibo radar images. All other longitudes display Mariner 10 and MESSENGER Mercury flyby 1 images of the surface. The "closest point" marker indicates the point on Mercury's surface below MESSENGER at closest approach. The animation covers the period within three hours of closest approach.

Mercury Flyby 3
On September 29, 2009, MESSENGER again zips past the same hemisphere observed during its second flyby of Mercury. Mariner 10 images and MESSENGER images from the first two Mercury flybys make up the globe of Mercury. Watch the encounter from MESSENGER (5.78 MB or 2.59 MB) and over Mercury's north pole (2.23 MB or 1.26 MB).

Mercury Flyby 3 Instrument Operations for the Full Encounter
This animation (94.9 MB) shows the spacecraft maneuvers and instrument observations planned for MESSENGER's third flyby of Mercury on September 29, 2009. The animation covers a time from about two hours prior to closest approach to about two and a half hours after the spacecraft's nearest pass to the planet's surface. (Small version without labels: 31 MB)

Mercury Flyby 3 Targeted Observations
This animation (9 MB) shows a sped-up representation of the targeted dayside observations during MESSENGER's third Mercury flyby, compressing about 18 minutes and 40 seconds of observations into 38 seconds. The animation begins as MESSENGER's instrument deck boresight crosses the dawn terminator and the Mercury Laser Altimeter (MLA) takes its final ranging observations (shown as pink circles). As MLA turns off, the movie shows the footprints of the Visible and Infrared Spectrograph (VIRS) channel (shown in green) of the Mercury Atmospheric and Surface Composition Spectrometer (MASCS). For each targeted observation, the MESSEGNER boresight is set to track a single point on the surface for ~35 seconds, taking a series of full-color images with the Mercury Dual Imaging System (MDIS) wide-angle camera, shown as blue frames in the movie, and a full set of spectra with the VIRS and Ultraviolet and Visible Spectrometer (UVVS) channels of MASCS.

Mercury Flyby 3 Maneuvers for the Neutron Spectrometer
This animation (7.8 MB) shows maneuvers of the MESSENGER spacecraft during a portion of the third Mercury flyby. Several of the maneuvers are designed to improve the capability of MESSENGER’s Neutron Spectrometer (NS) to identify neutron-absorbing elements, most notably iron (Fe) and titanium (Ti), on Mercury’s surface. Thermal neutrons are measured with the Doppler filter effect, which uses the spacecraft velocity (5 km/s) and orientation to identify the slower (2.2 km/s) thermal neutrons. The graph at lower right shows predicted neutron counting rates for three different average surface compositions; blue, green, and red curves denote counting rates for low, medium, and high amounts of Fe and Ti, respectively. The Doppler filter effect reaches its peak neutron enhancement during the spacecraft rotation maneuver at 21:46 UTC. It is at this time that neutrons provide the strongest discriminator of Mercury’s surface composition, as seen by the separation among the three colored curves.

Mercury Flyby 3 - Ground Track views
This animation (26 MB) shows the spacecraft's ground track on Mercury's surface with time ticks every two minutes and labeled latitude and longitude lines. The latitude, longitude, and altitude of MESSENGER are shown every 10 seconds within one hour of closest approach on September 29, 2009. The view of Mercury combines Mariner 10 spacecraft images, MESSENGER Mercury flyby 1 and 2 images and surface feature names.

View the track below MESSENGER (4 MB) while viewing a projection of the entire surface of Mercury. The view of Mercury’s surface  includes images from Mariner 10 and MESSENGER’s Mercury flybys 1 and 2. The "closest point" marker indicates the point on Mercury's surface below MESSENGER at closest approach. The animation covers the period within two hours of closest approach.

Arrival at Mercury
During the first orbit of Mercury on March 18, 2011, MESSENGER sees Mercury’s cratered surface from an orbit that nearly follows the planet’s dawn-dusk line. View the orbit insertion maneuver and first orbit from just beyond MESSENGER (7.61 MB or 3.65 MB) and from high above Mercury's north pole (5.98 MB or 3.75 MB). The pale green part of the trajectory highlights MESSENGER’s path during the orbit insertion maneuver.

Mercury Orbit Insertion
This animation (36 MB) shows a model of the MESSENGER spacecraft above Mercury with a sunspot-speckled Sun in the center of each frame. During the 15-minute Mercury orbit insertion maneuver, various thruster plumes are visible as the spacecraft’s large thruster is pointed near the direction of motion – effectively slowing the spacecraft enough to place MESSENGER into a 12-hour orbit around Mercury. Note the updates every second indicating altitude, latitude beneath the spacecraft, velocity change (also called delta-V), propellant usage, and percentage completion of delta-V. This perspective depicts how the sunshade protects all but the solar arrays, which are tilted far from “face on” toward the Sun in order to prevent overheating.

Mercury Orbit Insertion - as it happened
This animation (87 MB) shows a model of the MESSENGER spacecraft above Mercury with the Sun in the center of each frame. During the 15-minute Mercury orbit insertion maneuver, various thruster plumes appear as they occurred with the spacecraft’s large thruster pointed near the direction of motion – effectively slowing the spacecraft enough to place MESSENGER into a 12-hour orbit around Mercury. Final data from the spacecraft and its orbit are the basis for one-second-resolution updates indicating altitude, latitude beneath the spacecraft, velocity change (also called delta-V), propellant usage, and percentage completion of delta-V. The small light gray spot at Mercury’s north pole represents the largest area of Mercury’s surface without spacecraft image coverage from either MESSENGER or Mariner 10 as of December 1, 2011. The locations of stars at magnitude 9 or brighter are also displayed as small white dots.

MOI with 1.5 orbit after insertion
Watch this animation (40.4 MB) to view the Mercury orbit insertion maneuver and the spacecraft's first orbit around the planet.

Extended Mission Transfer to 8-hour Orbit
MESSENGER completes two maneuvers in April 2012 in order to lower the time for each orbit of Mercury from 11.6 to 8.0 hours (215 MB).

MPEG

Solar Panel Deployment 1
Shortly after lifting off from Cape Canaveral Air Force Station, Florida, MESSENGER deploys the first of its two solar panels. (3.16 MB)

Solar Panel Deployment 2
MESSENGER deploys its second solar panel. (3.02 MB)

Science Instruments
A view of MESSENGER’s science instruments inside the launch vehicle adapter ring (2.74 MB).

Orbit Insertion
MESSENGER prepares to perform the Mercury orbit insertion burn (1.37 MB).

MESSENGER in Orbit
View of MESSENGER in orbit at Mercury (2.21 MB).

Extended Mission Transfer to 8-hour Orbit
MESSENGER completes two maneuvers in April 2012 in order to lower the time for each orbit of Mercury from 11.6 to 8.0 hours (30.1 MB).