ITHACA, N.Y. — A collective sigh of relief could be heard around the
corridors of Cornell University’s Space Sciences Building late
Tuesday night when the Mars Odyssey spacecraft went into orbit around
Mars. The main reason for the jubilation: The small robotic
spacecraft will be the key communications link for the Mars
Exploration Rover (MER) mission in 2003.

“Everything went perfectly, and this is fabulous news for the Rover
program,” says Cornell Professor of Astronomy Steven W. Squyres, who
has a leading role in both NASA’s Odyssey and Rover missions. He is
a member of the science team for the gamma ray spectrometer (GRS),
one of three instruments carried by the Odyssey. And he is principal
investigator, or leader, of the larger international team that is
developing the Athena science package to be carried by the two Rover
vehicles during their planned exploration of the red planet in 2004.

If the $300 million Odyssey mission had failed, the Rover program
could have been seriously hampered, perhaps even jeopardized. That
is because the two exploration vehicles would have had only the aging
Global Surveyor spacecraft, which went into Mars orbit in September
1997, to provide communications with Earth. Now the two Rovers will
be able to upload data — in such areas as the mineral and element
composition of rocks and soils — to a state-of-the art
communications package. The Odyssey relay antenna will then transmit
the data to Cornell’s Space Sciences Building.

Squyres has been associated with the gamma ray spectrometer
instrument package on board Odyssey since 1986, well before the Mars
Rover program was planned. However, the original landing of a single
Rover was planned for this year, to coincide with the Odyssey
mission, but was canceled by NASA. The $700 million MER mission was
announced by the space agency in August last year, with launches
planned for May and June, 2003, and landings on the planet for Jan. 4
and 5, 2004. Although the Odyssey’s GRS will play an important role
in determining the elements that make up the Martian surface,
measuring the abundance and distribution of about 20 primary
elements, Squyres does not expect the instrument to play a role in
picking the landing sites for the two Rovers. However, another
Odyssey instrument, THEMIS (thermal emission imaging system), is
expected to provide data on minerals in soils and rocks that will aid
understanding of the four potential landing sites chosen for the
Rovers at a recent meeting at the Jet Propulsion Laboratory (JPL) in
Pasadena, Calif. The sites were chosen on the basis of images from
Global Surveyor and are areas where there is the best evidence
possible that water was once present on the surface. Squyres
describes the four sites as “fabulous,” and says that the two final
sites will be selected within six months.

The planning for the two Rovers, each a 300-pound mobile laboratory,
is intense. Says Squyres, “The payload is going well. The schedule,
overall, is tight. But we are going to make it.”

A critical interpretation of the Odyssey GRS data also will be
carried out at Cornell by graduate student Amena Siddiqi who is
writing her doctoral thesis on the likely sources of ice on Mars. It
is known that ice exists in the Martian polar regions, but it is not
known if there is ice beneath the soil in other latitudes. The GRS
can actually see through the planet’s soil to deposits of ice below.
Siddiqi, a British citizen who is a native of Pakistan, will use
Odyssey data to develop maps that could show where the ice deposits
exist.

The Odyssey GRS team leader is William Boynton of the University of
Arizona. Both the Odyssey mission and the 2003 Rover projects are
managed by JPL.

Related World Wide Web sites: The following sites provide
additional information on this news release. Some might not be part
of the Cornell University community, and Cornell has no control over
their content or availability.

o Mars Odyssey: http://mars.jpl.nasa.gov/odyssey/

o Athena: http://athena.cornell.edu/