MESSENGER Lines Up for Venus Flyby
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 yesterday placed the spacecraft on track for its next major mission event: the first Venus flyby on October 24, 2006.
Having completed six successful small TCMs that utilized all 17 of the spacecraft’s thrusters, this latest maneuver was the first to rely on the four B-side thrusters. During this maneuver, the thrusters on the opposite side of the spacecraft reduced a build-up of angular momentum due to an unseen force that causes the spacecraft to rotate if left uncorrected. This maneuver was only the seventh actual TCM for MESSENGER; the spacecraft’s trajectory was so close to optimal after TCM 3 and TCM 6 that planned TCMs 4, 7 and 8 weren’t necessary.)
The maneuver started at 11 a.m. EST; mission controllers at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, verified the start of the maneuver within 11 minutes and 48 seconds, when the first signals indicating spacecraft thruster activity reached NASA’s Deep Space Network tracking station outside Goldstone, Calif.
At the start of the maneuver, the spacecraft was 132 million miles (212 million kilometers) from Earth and 83 million miles (133 million kilometers) from the Sun, speeding around the Sun at 68,163 miles (109,698 kilometers) per hour.
For graphics of MESSENGER’s orientation during the maneuver, visit the “Trajectory Correction Maneuvers” section at http://messenger.jhuapl.edu/the_mission/mission_design.html.
Earth Flyby Image Gallery Now Online
MESSENGER’s Mercury Dual Imaging System (MDIS) acquired spectacular images during the Earth flyby in August 2005, including a “film” of our home planet as it receded in the distance. Now, you can browse through the best of the MDIS flyby frames on the MESSENGER Web site!
Visit the MDIS Earth Flyby gallery at http://cps.earth.northwestern.edu/MESSENGER_20050802/.
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury, and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on Aug. 3, 2004, and after flybys of Earth, Venus and Mercury will start a yearlong study of its target planet in March 2011. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages the Discovery-class mission for NASA.