Spirit Spends First Full Days on Mars; Scientists Report "More Good News"
"There's more good news, I'm afraid," Spirit mission manager Matt Wallace told reporters this morning at what has now become the daily briefing.
Wallace and other Spirit scientists and engineers brought out a 10-foot photograph in two rectangular frames -- the first 3-D panorama landscape shot of Mars Exploration Rover Spirit's landing site in Gusev Crater, taken by the navigation camera.
With additional data due later today and early tomorrow morning, the mission team is hoping to receive and piece together the first color picture perfect panoramic postcard -- from the PanCam, a high resolution stereo vision camera -- for the briefing tomorrow,
Spirit meanwhile spent its first full day on Mars yesterday, after bouncing to a stop at 8:35 p.m. Pacific Standard Time (PST) last Saturday night. It returned at least 22.7 more megabits of data and passed its physical. "Spirit has told us that it's healthy," announced Mars operations mission manager for Spirit, Jennifer Trosper last night. Additional programmed tests overnight, including unfolding the high gain antenna (HGA) and establishing a direct-to-Earth link, offered more of the same.
The HGA test was particularly important, because this antenna is capable of returning large amounts of data quickly. The plan now calls for data to be returned for 2-3 hours a day via the HGA, at up to 11,800 bits per second. "The rover is indeed very healthy," Spirit Mission Manager Matt Wallace confirmed this morning. "Everything looks healthy."
The golf-cart-sized robot geologist is charged with exploring for clues in rocks and soil that might indicate the past environment at this part of Mars was ever watery and suitable to sustain life. And Gusev may just be a good place to find out, because many Mars scientists believe that it once held a lake. If it did, and Spirit could prove it, that finding would certainly up the ante that other, extraterrestrial life does exist, for where there is water there is life -- and that could change the way we look at life forever.
For now, Spirit remains perched on its lander platform, and the next nine days or more it will go through the motions and commands that will prepare it to make an elegant egress onto the Martian surface. With only two degrees of tilt, with the deck toward the front an average of only about 15 inches (37 centimeters) off the ground, and with apparently no large rocks blocking the way, the lander appears to be in good position for egress. "The egress path we're working toward is straight ahead," Trosper said.
Once the robot geologist was put to sleep for the night, however, scientists and engineers returned their focus back to the more than 64 images, and other technical and engineering data transmitted through both Mars Odyssey and Mars Global Surveyor (MGS) and began the process of analyzing the data.
Things returned to business as usual this morning at JPL, where Spirit and twin Opportunity were designed and built. But the spirit-lifting event of the weekend seemed to have everyone smiling. While the spirits remain buoyant, the brains and feet are dragging a bit. Few of the team members have gotten any sleep at all.
Flight director Jason Willis and Prasun Desai, EDL trajectory analyst said last night that they are just beginning to review and analyze the data recorded during entry, landing and descent and still have not yet determined if the last minute 'tweaks'- including opening the parachute earlier, which they said actually opened a bit later than commanded -- made a difference in the landing.
The mission team is also reviewing the images to figure out where Spirit is. By correlating images taken by Spirit with earlier images from spacecraft orbiting Mars, the team has determined that the rover appears to be in a region marked with numerous swaths where dust devils have removed brighter dust and left darker gravel behind. Although they don't know exactly where Spirit is yet, they have determined that the rover is facing south, and that they are about six miles from the center of the targeted landing site within the crater. And that is it, for the scientists, the "sweet spot," complete with just enough rocks, and no threatening obstacles.
"This is our new neighborhood," said Steve Squyres, Cornell University professor and principal investigator of the science package aboard both Spirit and Opportunity. "We hit the sweet spot. We wanted someplace where the wind had cleared off the rocks for us. We've landed in a place that's so thick with dust devil tracks that a lot of the dust has been blown away."
The terrain looks different from any of the sites examined by NASA's three previous successful landers -- the two Vikings in 1976-'77 and Mars Pathfinder/Sojourner in 1997. The Gusev landscape appears to be a vast stretch of flat land, fairly sparse with rocks -- enough rocks, but not too many and no big boulders to block threaten the rover's mobility, some intriguing dark patches, a few pointy ridges, and at least one prominent shallow crater nearby that they've already dubbed 'Sleepy Hollow.'
"What we're seeing is a section of surface that is remarkably devoid of big boulders, at least in our immediate vicinity, and that's good news because big boulders are something we would have trouble driving over," Squyres said yesterday. "We see a rock population that is different from anything we've seen elsewhere on Mars, and it comes out very much in our favor."
The extensive stretch of flat land is ideally suited to this rover's unprecedented mobility and scientific toolkit. In fact, at this morning's press briefing, Squyres says the team has homed in on Sleepy Hollow as a likely first target for Spirit, depending of course on what new data comes in between now and the time the decision for the rover's first assignment must be made.
Sleeping Hollow -- the first feature to get a name in these Martian chronicles -- appears to be about 30 feet in diameter, and about 40 to 50 feet away from the rover, Squyres said at the briefing this morning. While they have estimated its depth to be about two feet, it may be filled with layers of dust and actually be deeper than that, he added. "There may be a dozen of these pockmarked areas, which hypothetically could be high impact craters. I think it's plausible that they are secondary craters."
Once they get rolling and get a little driving experience under their belts, Squyres said he though they might be able to reach Sleepy Hollow in a day. "But we don't have our Martian drivers licenses yet," he pointed out. "So we will begin very, very cautiously."
The team is cautiously ecstatic about Spirit's vitality, and how each piece of equipment, each instrument so far is checking out with near-perfect marks and confidence is high that this rover will be able to carry out its mission.
"We had had a problem with the Mössbauer Spectrometer a couple of months back," Squyres reminded. [This spectrometers is specially designed to study minerals that contain iron, which are common on the Martian surface.] "While we had gotten it to work, we didn't know what was going to happen when we reached the surface. It scared the living daylights out of us. Well, remember the scene in the mission control room the other night?" he asked the media. Well, when the Mössbauer checked out, it was that same scene in the Mössbauer room -- only in German."
Art Thompson, the tactical uplink lead, was just as happily animated. "Wow!" he exclaimed. "Reality has far surpassed fantasy --she's just too easy to operate this point. We are kids at the candy store. We're not just looking inside. We're at the case deciding which way to go."
At the same time, they know they are not out of the woods yet. As Flight Director Jason Willis noted last night: "There are numerous things that can go wrong between now and egress from the lander. There are things that can still get us. But we think we're prepared."
The next big return -- especially for the public -- will be the color 3-D panorama picture taken by the PanCam, the stereo vision, high resolution camera designed to photograph the landscape. In yesterday's data streams, the team received all 12 frames in 'thumbnail' size -- the pieces needed to construct the first high resolution, 3-D color postcard, so while they know they have the data, they need to wait for tonight's pass of the Mars Odyssey to get the rest of the bits of data to complete the full size image they hope to present tomorrow morning.
Today, the mission team will be getting more data from Odyssey late this afternoon and early tomorrow morning, and from MGS at midnight tonight. The mission team plans to spend the rest o fits time conducting more tests and following the plans to put Spirit on the road.
Specifically, they will retract the airbags a bit more, three revolutions, and try to make additional determinations about the areas where the bags appear to be 'bubbled' or 'poofed up'. One of the first images returned showed what at first appeared to be a rather large rock; they now believe that may be an airbag bubble or the airbag may be shrouding a rock beneath it.
They will also be further checking out the Miniature Thermal Emission Spectrometer -- more commonly called MiniTES -- which records the thermal spectra of various rocks and soils to determine the types and amounts of minerals that they contain.
And for many members of the mission team who have not slept since Friday night, sleep is also high up on the agenda. "It's time," sighed Squyres.
Spirit traveled 302.6 million miles [487 million kilometers] to reach Mars after its launch from Cape Canaveral on June 10, 2003. Opportunity, will reach its landing site on the opposite side of Mars at 9:05 p.m. PST on January 24 to begin a similar study of Meridiani Planum, a site on the opposite side of the planet from Gusev Crater. Each of these rovers will be able to roam hundreds of yards over their primary 90-day mission, covering more mileage in one day than predecessor Sojourner did in its entire Martian journey.