MARS ROVER'S SUDDEN SILENCE BAFFLES NASA
ENGINEERS
| Friday, January 23, 2004 NEWS 01A By Mike Lafferty |
Illustration: Photo Caption: Project manager Pete Theisinger said Spirit did respond to a signal from Earth. |
After nearly three weeks of great fortune, NASA engineers are trying to fathom why the Mars rover Spirit put itself to sleep and remained eerily silent yesterday.
The rover's radio works, but it is not communicating with its computer, said Pete Theisinger, the mission's project manager.
When controllers sent Spirit a signal yesterday to determine whether it would respond, it did -- a sign that probably indicates that the six-wheeled, golf-cart-size explorer is in operating condition.
"That would be good news, but it hasn't been confirmed,'' Theisinger said during a news briefing at the Jet Propulsion Laboratory in Pasadena, Calif.
Engineers are trying to duplicate the problem on Earth.
"We have to figure out why it has tripped itself into a safe mode,'' engineer Jaime Dyk said.
"Thermally, it's keeping itself warm. It's got power and it's just waiting for us to figure out why it crashed.''
The problem comes three days before Spirit's twin, Opportunity, is scheduled to land on the opposite side of the planet. The dual missions to examine Martian geology and search for water and signs of life cost $820 million.
Controllers planned to try to communicate with the rover through the Mars Global Explorer satellite last night, but said they would be surprised if it responded.
Glitches are not uncommon on deep-space probes. Periodic communications problems plagued the tiny Sojourner rover during the 1997 Mars Pathfinder mission.
Mars has been an especially tough planet for probes. NASA and other space agencies have littered the solar system with failed attempts.
In December, a Japanese orbiter missed the planet; the European Space Agency's explorer Beagle made it to Mars but has yet to call home.
In contrast, Spirit has worked beyond expectations since landing Jan. 3, treating the world to an almost daily spectacle of technological triumph. It has sent reams of photos since its landing, and just began roving last week.
But its three-month mission had barely begun.
It had just begun to examine a football-size rock scientists named Adirondack, and plans for today called for using its drill to examine the rock's interior.
But Spirit failed to transmit scientific data on Wednesday and yesterday.
"We have a very serious anomaly on the vehicle,'' Theisinger said.
Controllers and mission scientists, however, say they are confident the problem -- whatever it is -- can be fixed, especially if the rover is in otherwise good health.
"We are expecting recovery of the rover's status to normal. Nobody is saying the rover is gone,'' said Rongxing Li, an Ohio State University mapping expert working on the project's science team.
Li said the problem could be in the software.
"Nobody has conclusive results. It's all possibilities,'' he said. "If communication is good, they can try and reload the software. But there are lots of ifs.''
mlafferty@dispatch.com