MESSENGER Status Report December 6, 2004

MESSENGER is in good health and operating normally. After the
successful trajectory correction maneuver on Nov. 18 – the last in a series of
three maneuvers planned for early mission operations – the operations
team switched from commanding the spacecraft in real time to using
command sequences stored in MESSENGER’s onboard computer. Also, as
scheduled, the team has reduced its tracking time (contact with
MESSENGER through NASA’s Deep Space Network) from six 8-hour sessions a
week to three.

Science and engineering team members are analyzing results from the
first Mercury Dual Imaging System (MDIS) instrument calibration test
since launch. On Nov. 29, the spacecraft was tilted 27 degrees so the
camera could image sunlight reflected off a target inside the payload
attachment fitting, which surrounds MDIS and three other instruments on
MESSENGER’s underside. Operators have since returned MESSENGER to its
pre-test orientation.

Stat Corner: MESSENGER is about 98.6 million miles (158.6 million
kilometers) from the Sun and 25.7 million miles (41.3 million
kilometers) from Earth. At that distance, the amount of time for a
signal to reach the spacecraft from Earth is 2 minutes, 17 seconds.
Since liftoff, MESSENGER’s onboard computers have executed 18,682
commands from mission operators.