Maneuver Keeps MESSENGER on Track

MESSENGER marked its 52nd day of flight operations with a burst from its thrusters, completing a maneuver on Sept. 24 that kept it on course for next summer’s Earth flyby.

Carried out mostly by MESSENGER’s four medium (5-pound) hydrazine-fueled thrusters – with a little help from 8 of its 12 small (1-pound) thrusters – the 62-second burn corrected the last remaining trajectory errors from the spacecraft’s Aug. 3 launch. The short maneuver was a long-distance tap on the brakes, reducing MESSENGER’s velocity by about 10 miles an hour (4.6 meters per second) relative to the Sun. MESSENGER is now more than 11.5 million miles (18.5 million kilometers) from Earth, speeding through space at 62,319 miles (100,292 kilometers) per hour.

At that distance radio signals reach Earth in just over a minute – meaning the burn, which started at 2 p.m. EDT, was effectively over when mission operators at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, picked up MESSENGER’s signals through the NASA Deep Space Network tracking station near Madrid, Spain.

MESSENGER is currently flying with its sunshade away from the Sun, allowing it to keep its instruments and systems warm without using power for heaters. The spacecraft is in good health and operating normally; subsystem and instrument tests resume today when the operations team turns on MESSENGER’s instrument data processor (DPU-A) and checks its interfaces with the Magnetometer, X-Ray Spectrometer and Mercury Atmospheric and Surface Composition Spectrometer.

Visit the Mission Design <http://messenger.jhuapl.edu/the_mission/mission_design.html#tcm> section for graphics and more details on the trajectory correction maneuver. The next maneuver is planned for Nov. 18.