[meteorite-list] MESSENGER Celebrates 1, 000 Earth Days in Orbit around Mercury

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 11 Dec 2013 16:18:43 -0800 (PST)
Message-ID: <201312120018.rBC0IhRH007315_at_zagami.jpl.nasa.gov>

http://messenger.jhuapl.edu/news_room/details.php?id=248

MESSENGER Mission News
December 11, 2013

MESSENGER Celebrates 1,000 Earth Days in Orbit around Mercury

Later today, the MESSENGER spacecraft will have completed 1,000 Earth
days of flight operations in orbit around Mercury. "This milestone is a
testament to the outstanding work of those who designed, tested, and
operated this spacecraft," says Jim McAdams of the Johns Hopkins
University Applied Physics Laboratory (APL) and the lead engineer for
MESSENGER's mission design team.

"MESSENGER was designed to function for eight years following launch and
to withstand the harsh environmental conditions of the inner solar
system and solar heating up to 11 times greater than experienced by
spacecraft near Earth," McAdams says. "The probe not only has continued
to function, it has thrived, with very little loss of planned
observations for more than nine years and four months since launch."

"To date, the spacecraft has returned 198,166 images from orbit about
Mercury, far exceeding the mission's original plans," says APL's Rob
Gold, MESSENGER's Science Payload Manager. "In the original mission
concept we were planning to use half of the telemetry for images and the
rest for the other instruments, and that plan would have returned about
1,000 images of the surface of Mercury. That we are now approaching
200,000 images is the result of major technological improvements made
during construction of MESSENGER."

"Some of the improvements were in the hardware," he noted, "including
the development of an electrically steered phased-array antenna. Others
were in operational techniques, such as the use of the CCSDS
(Consultative Committee for Space Data Systems) File Delivery Protocol,"
a highly specialized protocol designed to overcome space operations
communications challenges.

The orbital phase of the MESSENGER mission, which was originally
designed to last one Earth year, is now nine months into a second
extended mission that is scheduled to conclude early in 2015. The lowest
point of MESSENGER's orbit is now 325 kilometers (201 miles) above
Mercury's surface. This minimum altitude will continue to decrease until
the first maneuver of the mission's low-altitude campaign in mid-June 2014.

"MESSENGER has not merely survived life in a tough neighborhood, it has
produced a string of major scientific discoveries that have transformed
our understanding of the innermost planet and how the inner solar system
was formed," adds MESSENGER Principal Investigator Sean Solomon of
Columbia University. "And we expect those discoveries to continue as
MESSENGER begins to pass progressively closer to Mercury's surface than
ever before."
------------------------------------------------------------------------
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 August 3, 2004, and
entered orbit about Mercury on March 17, 2011 (March 18, 2011 UTC), to
begin a yearlong study of its target planet. MESSENGER's first extended
mission began on March 18, 2012, and ended one year later. MESSENGER is
now in a second extended mission, which is scheduled to conclude in
March 2015. Dr. Sean C. Solomon, the Director of Columbia University's
Lamont-Doherty Earth Observatory, leads the mission as Principal
Investigator. The Johns Hopkins University Applied Physics Laboratory
built and operates the MESSENGER spacecraft and manages this Discovery-
class mission for NASA.
Received on Wed 11 Dec 2013 07:18:43 PM PST