MESSENGER: MErcury Surface, Space ENvironment, GEochemistry, and Ranging

A NASA Discovery mission to conduct the first orbital study of the innermost planet

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MESSENGER Telecon Multimedia Page

Presenter #1

Marilyn Lindstrom, MESSENGER program scientist
NASA Headquarters, Washington

Image 1.1—Mercury Orbit Insertion

MESSENGER prepares to perform the Mercury orbit insertion burn.
(Click the image above to view the animation.)

Presenter #2

Eric Finnegan, MESSENGER mission systems engineer
The Johns Hopkins University Applied Physics Laboratory, Laurel, MD

Image 2.1—MESSENGER's Demanding Trajectory This animation depicts the demanding trajectory of the MESSENGER spacecraft during the cruise phase of the mission, from launch on August 3, 2004, through Mercury Orbit Insertion (MOI) on March 18, 2011. Shown here is a view of the inner planets’ motions looking down from the Ecliptic North Pole, where the line between the Sun and the Earth is held fixed in space. During MESSENGER’s 6 year, 7 month journey, it will fly by three planets: once by Earth at an altitude of approximately 2,300 kilometers (1,429 miles); twice by Venus at an altitude of approximately 3,000 kilometers (1,864 miles) and 330 kilometers (205 miles) and then three times by Mercury at an altitude of approximately 200 kilometers (124 miles). In addition to these flyby opportunities—critical to slowing the velocity of the spacecraft—MESSENGER will execute five deep space maneuvers using the on-board bi-propellant propulsion system, firing the main engine to further aid in slowing the spacecraft on its approach for Mercury orbit capture. The cruise phase of the mission concludes with the largest maneuver sequence for the mission, placing the spacecraft in an elliptical orbit around Mercury, passing within 200 kilometers (124 miles) of the surface every 12 hours. Also during the cruise phase, the relative geometry between the spacecraft, the Earth and the Sun, referred to as the Sun-Earth-Probe (SEP) angle, align such that communications between the spacecraft and the Deep Space Network is precluded. These superior conjunctions are estimated to start and end when the SEP angle is less than 3 degrees. There are nine of these conjunctions during cruise operations, the longest of which will occur on October 25, 2007 and lasts for 48 days. (Click the image on the left to view the animation.)
Image 2.2—The MESSENGER Spacecraft

These sets of images present views of the MESSENGER spacecraft, in the deployed state; from the front and back (Left image) and from the bottom (Right image). The most recognizable feature of the spacecraft, the sun shade, is used to shield the spacecraft from solar radiation as the cruise trajectory and Mercury orbital operations place the spacecraft within 0.3AU of the sun. The locations for all seven instrument packages, including their individual instrument sensors are depicted. Note, the thermal blanket material that covers and insulates the spacecraft from cold space has been removed for clarity and viewing of the individual sensors.

Presenter #3

Sean Solomon, MESSENGER principal investigator
The Carnegie Institution of Washington, Washington

Image 3.1—MESSENGER Venus 2 Flyby MESSENGER Venus 2 Flyby		Image 3.2—Venus 2 Flyby As the MESSENGER spacecraft approaches the brightly illuminated Venus on June 5, 2007, 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 330 to 340 kilometer altitude closest approach. (click the image above to view the animation.)
Image 3.3—MESSENGER Venus 2 Flyby Observation Plan MESSENGER Venus 2 Flyby Observation Plan		Image 3.4—MESSENGER Venus 2 Flyby and Venus Express Orbit MESSENGER's Venus 2 flyby will occur when the European Space Agency's Venus Express mission continues to operate in orbit around Venus. The complementary viewing geometries and instrument sets for the two spacecraft will permit an unprecedented opportunity for two-platform observations of the Venus atmosphere, clouds, and interplanetary environment. A closely coordinated campaign of observations is planned of atmospheric dynamics, cloud structure, and atmospheric chemistry by the MDIS and MASCS instruments on MESSENGER and the Venus Monitoring Camera and VIRTIS instrument on Venus Express. Two-point measurements of the penetration of the interplanetary magnetic field into the Venus ionosphere, plasma boundaries, and tail will be made by MESSENGER's Magnetometer and EPPS instrument and by the Magnetometer and ASPERA instrument on Venus Express. (Click the image above to view the animation.)
Image 3.5—Mercury Flyby 1 As the MESSENGER spacecraft encounters the mostly darkened Mercury it will begin a detailed sequence of science observations that are designed to acquire close-up images and science measurements for the first time since the third Mariner 10 Mercury flyby nearly 33 years ago. This animation shows how Mercury will appear from the spacecraft’s perspective from one hour before the 200 kilometer altitude closest approach to one hour after closest approach. Shortly after closest approach the spacecraft will acquire color and monochrome images of part of the hemisphere of Mercury never viewed by the Mariner 10 spacecraft during its three Mercury flybys in 1974 and 1975. Three Mercury gravity-assist flybys are needed to change the spacecraft's trajectory enough to enable Mercury orbit insertion in March of 2011. (click the image above to view the animation.)

Presenter #4

Hakan Svedhem, Venus Express project scientist
European Space Agency, Noordwijk, The Netherlands

Image 4.1		Image 4.2
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