MEDIA RELATIONS OFFICE

JET PROPULSION LABORATORY

CALIFORNIA INSTITUTE OF TECHNOLOGY

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011

http://www.jpl.nasa.gov

Mars Polar Lander Mission Status

December 5, 1999

Mission controllers for NASA’s Mars Polar Lander have revised their
strategy as they continue trying to make contact with the spacecraft.

“We’re nearing the point where we’ve used up our final silver
bullets,” said the mission’s project manager, Richard Cook of JPL, after
Sunday night’s unsuccessful attempt to communicate with the spacecraft.

Engineers will try to contact the lander again on Tuesday, Dec. 7 at
12:20 a.m. Pacific Standard Time, by directing Mars Polar Lander to use its
UHF radio to communicate through a relay system onboard NASA’s
currently-orbiting Mars Global Surveyor. Most of the attempts to receive a
signal from the lander over the past few days have used its medium gain
antenna.

“Our probability of success will diminish significantly after this
next attempt,” Cook said, “but the team is still exploring all possibilities
for establishing comunications with the lander.”

Controllers are preparing a set of computer commands to have the
lander conduct a full sky search for Earth within the next couple of days.

Mars Polar Lander is part of a series of missions in a long- term
program of Mars exploration managed by JPL for NASA’s Office of Space
Science, Washington, D.C. JPL’s industrial partner is Lockheed Martin
Astronautics, Denver. JPL is a division of the California Institute of
Technology in Pasadena.

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