[meteorite-list] Spirit's Hidden Secrets: Trapped Within the Rover, Unique Data Captured with Mars Express

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:09 2004
Message-ID: <200401270043.QAA09684_at_zagami.jpl.nasa.gov>

http://space.com/missionlaunches/spirit_express_040126.html

Spirit's Hidden Secrets: Trapped Within the Rover, Unique Data Captured with Mars Express
By Leonard David
space.com
26 January 2004

PASADENA, Calif. -- As it silently sits in Gusev Crater, NASA's Spirit Mars
rover is frozen in time. It holds in its memory files unique data that can
help unlock the secrets about Mars rocks and the planet's atmosphere,
including a rare combination analysis completed with the help of the
European Space Agency's Mars Express.

On Wednesday, January 21, Spirit was preparing to run its Rock Abrasion Tool
(RAT), a grinding device that removes dust and weathered rock, on the
exposed fresh rock "Adirondack" when the robot came to a screeching halt.
The leading theory is that the robot suffered a breakdown in software that
controls file management of its memory.

Right now, Ron Greeley, a Science Operations Working Group Chair for the
rover effort from Arizona State University in Tempe, and others in his group
are trying to figure out what data could be in memory, and of those data,
what's the prioritization.

"We've been looking at what are the things that we want to get back. There
are some things that are unique data [that] we'll never have a chance to get
again," Greeley said.

"We're working through what might be in memory, " said Greeley. "So if
there's any choice, we want this first, then this, then this - and work down
the list that way."

Mars Express and Spirit Data

Held tight in Spirit's memory software are choice science products. That
library of knowledge includes first looks at the Adirondack rock using the
Mössbauer Spectrometer and Alpha Particle X-ray Spectrometer, called the
APXS for short.

When Spirit is brought back to health, scientists want to move ahead and use
the RAT on Adirondack. But the pre-RAT spectrometer data is important for
before-and-after comparisons. So that data set is a very high priority,
Greeley said.

Both the Mössbauer Spectrometer and the APXS units have built-in memory. But
that information is relayed through Spirit's central brain control. These
instruments could be re-queried, but it would take many hours to regain the
same data that could be lost.

But Greeley also pointed out that a unique set of data onboard Spirit
involves the overhead pass of Europe's Mars Express. There was coordination
of Spirit looking up while Mars Express instruments looked down on the site.
Doing so would give scientists a one-of-a-kind profile in time of
atmospheric particles in the Gusev Crater region, he said.

"There's nothing absolutely critical," said Jim Bell, Payload Element Lead
for the MER Panoramic Camera (Pan Cam) from Cornell University. "If they
have to pull the plug - so be it - if we need to do that to move on. Maybe the
worst hit would be those measurements taken during the Mars Express over
flight. We were taking data the same time they were."

"We got back the little thumbnails [of data], but we didn't get back many of
the big full-frame images from that sequence. And that can't be repeated
until the next time that spacecraft flies over. But if that's the worst that
we lose some of that data, it's not going to affect mission success," Bell
said. "We don't want to lose any data of course."

Spirit in rehab

Things are progressing well here at JPL in trying to regain Spirit's
sensibility.

Troubleshooting is going on around-the-clock, said Jennifer Trosper, JPL's
MER Mission Manager. It could be two-to-three weeks of work before Spirit is
back in a driving state, she said today at an early morning press briefing.

>From its early flat-lined medical condition, Spirit is now in rehab, Trosper
said.

Too many memory files, too many tasks being fulfilled, and not enough
deleting of less-needed data appears to have conspired to upset Spirit.

"For this mission to be successful, a lot of things have to happen at the
same time," said Bell "There were 18 days in a row of this ballet of the
engineers, the scientists, the data management people, and the software
people -- all working together juggling everything," he added.

Bell said he doesn't think Spirit's situation was brought about by
overworked or tired personnel, or somebody hit the wrong button. "I don't
think that's the situation," he said.

Also locked within Spirit's memory are older Pan Cam shots when Spirit still
sat on its lander. There are some pieces of a horizon panorama too, and
pictures of the robot's arm deploying science instruments.

Deep space gremlins

Spirit has already delivered an amazing legacy of scientific data, with by
far the best images and spectra ever obtained for another world," said James
Garvin, NASA Lead Scientist for Mars Exploration within the Office of Space
Science in Washington, D.C.

"I am literally speechless over what it has achieved in only 18 sols of
science operations, intermixed with many steps to get moving on the real
Mars. And over the next weeks to months, I am confident the MER science team
will uncover some of the mysteries of Mars, from the nature of the soils - to
the basic chemistry and mineralogy of local materials," Garvin told
SPACE.com .

"I believe that our team will get Spirit moving again, doing science and
delivering on its promise," Garvin said. "We have only begun to fight the
"deep space gremlins" and Spirit will be back in business."
Received on Mon 26 Jan 2004 07:43:31 PM PST