Mars Odyssey
NASA’s Mars Odyssey orbiter sets a new record for longevity
with each passing day and has worked longer at the Red Planet
than any other spacecraft in human history.
It was launched on April 7, 2001 atop a Delta II rocket from
Cape Canaveral Air Force Station, Florida. After an
interplanetary journey of hundreds of millions of miles,
it arrived at Mars way back on Oct. 24, 2001 and
fired its main engine to brake the crafts speed and
allow it to be captured by Mars and enter a highly
elliptical orbit.
The previous Martian record holder was the Mars
Global Surveyor (MGS) orbiter which operated
in orbit from Sept. 11, 1997 to Nov. 2, 2006 until
contact was lost following a computer glitch.
A technique known as aerobraking was used over
the next three months to fly Odyssey through the upper
atmosphere of Mars and utilize drag to gradually lower
the crafts altitude and eventually enter its science mapping
orbit.
Odyssey has made numerous high impact scientific discoveries
along the way since science operations began in February
2002. Within a few months, Odyssey made the key discovery of
the entire mission when it found that the polar regions harbored
substantial caches of water ice within a meter of the dry surface
of Mars.
The detection of water – in the form of hydrogen — from orbit
using the crafts Gamma Ray Spectrometer led directly to the
proposal for the Phoenix mission which confirmed the discovery
in 2008. Phoenix landed directly on top of vast sheets of frozen
water ice in the northern polar region of Mars and scooped up
samples of ice for analysis by the landers science suite.
Odyssey also relayed most of the science data from Spirit,
Opportunity and Phoenix and is continuing that task for the new
rover Curiosity.
Mars Odyssey is equipped with three primary science
instruments;
• THEMIS (Thermal Emission Imaging System), for determining
the distribution of minerals, particularly those that can only
form in the presence of water;
•
GRS (Gamma Ray Spectrometer), for determining the
presence of 20 chemical elements on the surface of Mars,
including hydrogen in the shallow subsurface (which acts
as