BY SPACEFLIGHT NOW
Posted: January 25, 2004
After a seven-month voyage spanning 300 million miles from Earth to Mars, the Opportunity rover ended up inside a tiny crater to the utter delight of mission scientists.
 Imagery from Opportunity is combined to generate this "overhead" view of the rover sitting on its lander at Meridiani Planum. Credit: NASA/JPL Download a larger version of this image here. |
"We knew going in that there are two fundamental geological units here," Steve Squyres, the Mars rover principal investigator, said of the flat plains of Meridiani. "One of them is a thick sequence of layered rocks, fairly light in tone. We do not know what they are. And then draped on top of that is a thin coating of what appears to be some kind of fine-grain material, and that's the stuff we think contains the hematite.
"My fondest hope after looking at pictures from orbit before we landed was that we would land some place that we would be close enough to a crater that we would have a chance of traversing to it and actually getting to the layered material.
"Instead, what has happened is we have scored a 300-million mile interplanetary hole in one and we are actually inside a small impact crater!"
Images taken by Opportunity soon after touchdown revealed the $400 million craft was sitting in a shallow crater about 65 feet in diameter.
"I don't know what the odds would be for us hitting a crater like this, but this is just sensational," said Squyres.
A side wall of the crater is covered with a light-colored layer of fractured rock. This tantalizing rock outcrop along with the surface-covering material means Opportunity has its scientific objectives dead ahead.
"If it got any better, I couldn't stand it," said Dr. Doug Ming, rover science team member.
 This "postcard" from Opportunity's panoramic camera shows the strange martian landscape southwest of the rover. Credit: NASA/JPL/Cornell Download a larger version of this image here. |
The rover will probe the hematite to determine if the material is from sediments of an ancient ocean, from volcanic deposits altered by hot water, or from other environmental conditions in the planet's distant past.
"Hematite forms in a number of different ways on Earth but most of them involve the action of liquid water," Squyres said.
The battle cry of NASA's Mars exploration program is "follow the water." Proving that Mars once had liquid water would help to determine if the planet could have supported life long ago.
"Knowing just how the hematite on Mars was formed will help us characterize the past environment and determine whether that environment was favorable for life. One big question, of course, is whether life ever started on Mars. This mission probably won't tell us that, but it may well lead to future mission that can answer that question," said Joy Crisp, rover project scientist.
As Opportunity was descending to the surface, a camera package on the lander snapped three photographs. The imagery shows a much larger crater -- about 500 feet across -- within a half-mile of the landing site.
"It is surely, I think, within our reach," said Squyres.
"The way I envision this mission going: we drive off the lander, we look at the soil, we investigate this hematite mystery, we go to the outcrop, we explore it in some detail because it is right there in front of us, ripe for the pickin', we look at that carefully, we understand that geologic unit, then we climb out of the crater, look around and then head for the big one. And it is going to be a wonderful adventure."
But before Opportunity can depart its lander base, it must first stand up, deploy its wheels and cut a series of umbilicals. Engineers believe it will be the end of next week before the craft rolls onto the surface.
 This first image from the lander's descent camera was taken at an altitude of 1,986 meters (6,516 feet). The image spans approximately 1.6 kilometers (1 mile) across the surface of Mars. Credit: NASA/JPL Download a larger version of this image here. |
 This second image from the lander's descent camera was taken at an altitude of 1,690 meters (5,545 feet). The image spans approximately 1.4 kilometers (7/8 of a mile) across the surface of Mars. Credit: NASA/JPL Download a larger version of this image here. |
 This second image from the lander's descent camera was taken at an altitude of 1,404 meters (4,606 feet). The image spans approximately 1.2 kilometers (3/4 of a mile) across the surface of Mars. Credit: NASA/JPL Download a larger version of this image here. |
Bogged down software could explain Spirit's ailment
BY SPACEFLIGHT NOW
Posted: January 25, 2004
The group working to unravel the glitch with Spirit and return the rover to action has narrowed the possible cause of its trouble to three potentials, officials said Sunday afternoon.
"Spirit is still serious but we are moving toward guarded condition now," rover project manager Pete Theisinger said. "I think we got a patient well on the way to recovery."
The rover experienced a problem last Wednesday, disrupting communications with Earth and halting all science activities. The breakdown happened while Spirit was performing a calibration of motors on the Mini-TES instrument.
"The leading theory is that the file management software module in the software has gone to some condition that it could not cope with -- that it was not robust enough for the operations we were engaged in when we had the flaw on Wednesday," Theisinger said.
On Saturday, engineers began focusing on the rover's flash memory and the way the software communicates with the computer memory. To get the rover operating, it was told to avoid using the flash memory for now.
On Sunday, the team was able to reset Spirit's computer to the non-flash utilization mode, Theisinger said. Also Sunday, the ongoing diagnostics determined the flash memory hardware aboard the rover to be healthy.
"There are two other theories that are not as well in competition but cannot be discounted, and they are being worked by anomaly subteams," Theisinger added.
"One is there was some kind of error or hardware issue on the motor control board. That's the circuit board with the electronics that control the motors. That's being examined.
"Also...there was a solar event Wednesday and the timing of that is being looked at with respect to correlation to the onset of our problems. The flash memories are sensitive to high-energy ions and neutrons when they are being read from and written to, and we were certainly engaged in a lot of that activity that day."
Theisinger remains hopeful that Spirit will resume its exploration adventure of Gusev Crater by mid-February.
"I think we've got a patient well on the way to recovery, and I think we have a very good chance now we will have a very good rover when we are done getting this thing back up. Although, once again, it will take some time to make sure that we have completely characterized the problem and that we are able to check out all of the functionality on the vehicle.
"You can't take anything for granted here. So I don't expect to be driving for a couple of weeks, maybe three."