NASA'S MESSENGER Spacecraft Begins Historic Orbit Around Mercury

"This mission will continue to revolutionize our understanding of
Mercury during the coming year," said NASA Administrator Charles
Bolden, who was at MESSENGER mission control at the Johns Hopkins
University Applied Physics Laboratory in Laurel, Md., as engineers
received telemetry data confirming orbit insertion. "NASA science is
rewriting text books. MESSENGER is a great example of how our
scientists are innovating to push the envelope of human knowledge."

At 9:10 p.m. EDT, engineers Operations Center, received the
anticipated radiometric signals confirming nominal burn shutdown and
successful insertion of the MESSENGER probe into orbit around the
planet Mercury. NASA's MErcury Surface, Space ENvironment,
Geochemistry, and Ranging, or MESSENGER, rotated back to the Earth by
9:45 p.m. EDT, and started transmitting data. Upon review of the
data, the engineering and operations teams confirmed the burn
executed nominally with all subsystems reporting a clean burn and no
logged errors.

MESSENGER's main thruster fired for approximately 15 minutes at 8:45
p.m., slowing the spacecraft by 1,929 miles per hour and easing it
into the planned orbit about Mercury. The rendezvous took place about
96 million miles from Earth.

"Achieving Mercury orbit was by far the biggest milestone since
MESSENGER was launched more than six and a half years ago," said
Peter Bedini, MESSENGER project manager of the Applied Physics
Laboratory (APL). "This accomplishment is the fruit of a tremendous
amount of labor on the part of the navigation, guidance-and-control,
and mission operations teams, who shepherded the spacecraft through
its 4.9-billion-mile journey."

For the next several weeks, APL engineers will be focused on ensuring
the spacecraft's systems are all working well in Mercury's harsh
thermal environment. Starting on March 23, the instruments will be
turned on and checked out, and on April 4 the mission's primary
science phase will begin.

"Despite its proximity to Earth, the planet Mercury has for decades
been comparatively unexplored," said Sean Solomon, MESSENGER
principal investigator of the Carnegie Institution of Washington.
"For the first time in history, a scientific observatory is in orbit
about our solar system's innermost planet. Mercury's secrets, and the
implications they hold for the formation and evolution of Earth-like
planets, are about to be revealed."

APL designed and built the spacecraft. The lab manages and operates
the mission for NASA's Science Mission Directorate in Washington.

For more information about the mission, visit:

http://www.nasa.gov/messenger

Source: NASA

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