MESSENGER Status Report: MESSENGER Executes Successful Flyby Test
July 5 ,2005

On June 28, the MESSENGER team successfully tested the spacecraft and instrument commands planned for the Aug. 2 flyby of Earth - the gravity assist that starts the next leg of the spacecraft's journey toward Mercury. The Earth flyby will send the spacecraft toward Venus. The first of two Venus flybys is planned for October 2006.

The test involved a 180-degree rotation to turn MESSENGER's sunshade toward the Sun; then five hours and 40 minutes of activities involving three instruments - the Magnetometer, the Mercury Atmospheric and Surface Composition Spectrometer, and the Mercury Dual Imaging System. Another 180-degree rotation returned the spacecraft back to the sunshade-away-from-Sun orientation.

On the basis of this rehearsal of spacecraft activities planned near the Earth flyby, mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, will make minor corrections to the final Earth flyby commands sent to the spacecraft. These corrections will maximize the quality of the science data collected for the flyby. In the coming weeks, the MESSENGER team will create the final Earth flyby command sequences, as well as perform additional simulations and reviews.


Several teachers from the MESSENGER Educator Fellows Program visited APL on June 30 to learn more about the mission's preparations for the Earth flyby. The program is a nationwide teacher training initiative whereby a cadre of 30 fellows - master science teachers at the elementary, middle and high school levels - will conduct educator workshops nationally, training up to 27,000 pre-K through grade 12 educators over the life of the mission.

These fellows are taught concept-based, inquiry-driven lessons developed by the MESSENGER education team. Forming the core of the MESSENGER Education Modules, these standards-based lessons address solar system science, planetary observations through history and the engineering associated with building and sending a spacecraft to another world. More information on these programs is available on the MESSENGER Education Web page.


Stat Corner: MESSENGER is about 90.8 million miles (146.1 million kilometers) from the Sun and 6.2 million miles (10 million kilometers) from Earth. At that distance, a signal from Earth reaches the spacecraft in 33.5 seconds. The spacecraft is moving around the Sun at 68,167 miles (109,704 kilometers) per hour. MESSENGER's onboard computers have executed 58,596 commands from mission operators since launch on Aug 3, 2004.