Mars Odyssey Mission Status November 30, 2001

Flight controllers for NASA’s 2001 Mars Odyssey
spacecraft report that Odyssey has reduced its orbit period to
just under 10 hours. The orbit period is the time it takes
the spacecraft to make one revolution around the planet.

During each aerobraking pass, when the spacecraft skims
the atmosphere to alter its orbit, Odyssey’s closest approach,
known as the periapsis, is just 103 kilometers (64 miles)
above the Martian surface. Its farthest point from the
planet, known as the apoapsis, is now 15,300 kilometers (9,500
miles).

“The Odyssey spacecraft is truly going to an unexplored
region as it passes through the northern martian atmosphere,
an area called the polar vortex,” said John Smith, an Odyssey
navigation team member who leads the aerobraking design at
JPL. “This experience has resulted in both a wealth of new
atmospheric information as well as puzzles to be solved in
daily aerobraking design activities.”

The spacecraft has completed 55 passes through the
martian upper atmosphere. Twelve maneuvers have been performed
thus far to control the spacecraft’s altitude in order to
achieve the proper orbit.

During aerobraking, the high-energy neutron detector is
the only science instrument taking data. It is turned off
briefly during each pass through the atmosphere.

The aerobraking phase is expected to finish in late
January 2002. At that point, Odyssey will be in its desired
circular orbit, and the science mapping mission will begin
sometime in early February.

JPL manages the 2001 Mars Odyssey mission for NASA’s
Office of Space Science, Washington, D.C. Principal
investigators at Arizona State University in Tempe, the
University of Arizona in Tucson, and NASA’s Johnson Space
Center, Houston, Texas, operate the science instruments.
Lockheed Martin Astronautics, Denver, Colo., is the prime
contractor for the project, and developed and built the
orbiter. Mission operations are conducted jointly from
Lockheed Martin and from JPL, a division of the California
Institute of Technology in Pasadena. NASA’s Langley Research
Center in Hampton, Va., is providing aerobraking support to
JPL’s navigation team during mission operations.