MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Mars Polar Lander Mission Status
December 4, 1999 11:15 p.m.
Mission controllers for NASA's Mars Polar Lander are
proceeding with their checklist in a continuing attempt to
communicate with the spacecraft.
On Sunday, Dec. 5 from 10:50 to 11:00 a.m. Pacific Standard
Time, they will try to hear the lander's signal by using NASA's
currently-orbiting Mars Global Surveyor spacecraft as a relay
system for the lander's UHF radio. Until this point, engineers
have tried to reach the lander via its medium gain antenna.
Controllers did not hear from the spacecraft during a
communications opportunity on Saturday, Dec. 4 at 8:30 p.m. PST.
They hoped to make contact during that window if, after landing,
the spacecraft had successfully pointed its antenna toward Earth,
then entered a safe, or standby mode.
"Now we can cross that scenario off the list," said Mars
Polar Lander project manager Richard Cook of JPL. "We're ready
to move on to the next possibility on Sunday morning, which we
hope will work if the spacecraft is not in safe mode, but has its
antenna pointed incorrectly. We're sprouting ideas as we go
along about how to contact the lander."
If contact is not established during that attempt,
additional attempts scheduled at this point will be made as
- Sunday, Dec. 5, from 10:10 to 11:10 p.m. using the
lander's medium gain antenna scan if it is in safe mode
but its antenna is not pointed correctly.
- Tuesday, Dec. 7, at 12:20 a.m. PST using Mars Global
Surveyor if Mars Polar Lander is in safe mode.
Analysis of the landing site reveals the spacecraft would
have touched down within 10 kilometers (6 miles) of the target
site on the Martian south pole, according to Dr. Sam Thurman at
JPL, the lander's flight operations manager. He said they see no
surface features that would obstruct the lander's view of Earth
and therefore hamper its communications capabilities.
Engineers for the Deep Space 2 microprobes are continuing
their attempts to communicate with the probes every two hours.
The microprobes, designed to impact Mars about 60 kilometers
(about 35 miles) north of the lander, will transmit data through
Mars Global Surveyor.
"The probes may have arrived in an area of high slopes,
rough terrain or sand dunes," said Deep Space 2 project manager
Mission engineers believe the probes have entered a phase
where they broadcast their data automatically for one minute out
of every five. "It's also possible that the probes' batteries
have not warmed sufficiently to power up the communications
system. We're checking into all possibilities."
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.