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| Spirit sent this image, artificially colored to show different rock compositions, looking toward the Columbia Hills, formerly known as East Hills. Over the next 40 or more Martian days the rover will drive toward the hills, about 2.5 kilometers (1.5 miles) away. NASA/JPL/Cornell Click on the image for a high-resolution version (2884 x 967 pixels, 3911K) |
Speaking at a press briefing at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., today (Thursday, April 8, 2004), Mars exploration manager Firouz Naderi, said the mission could be extended even beyond September. "If we do have healthy rovers at the end of September, we will entertain another extension," he said.
Cornell University astronomer Steven Squyres, who is leading the science team in charge of the science instruments and cameras carried by the two rovers, says that it's impossible to say how long the mission will last. "We have begun to realize that the power system on the rover, which could have been a limiting factor, is likely to hold out for a very long time. If power isn't the limiting factor, then something else will be," he says. "It could be that electronic parts will fail, or that mechanisms will wear out, and that sort of thing is very difficult to predict. What is important about the extension of the mission by NASA is that it means that the limiting factor will not be having the funding run out."
As Naderi spoke, the rover Spirit was heading towards its long-term target, dubbed Columbia hills, about 2.5 kilometers (1.5 miles) away, a journey that will establish the benchmark for long-distance driving on Mars, taking the vehicle one to two months to complete. New auto-navigation software being downloaded by the rovers' computers this week will add 20 to 22 meters (66 to 72 feet) a day to the rovers' current daily range.
On April 3 and 5, Spirit completed its expected performance of 600 meters (1,969 feet) of total drive distance and ended 90 Martian operational days after landing in Gusev crater on Jan. 3. On sol 89, Spirit set a short-lived record for Martian driving, with a single-sol distance of 50.2 meters (165 feet) that pushed the odometer total to 617 meters (2,024 feet).
Two days later, Opportunity shattered that mark with a 100-meter (328-foot) drive. Opportunity, which landed three weeks after Spirit, on Jan. 24, on the opposite side of Mars in Merediani Planum, will complete its expected performance when it finishes a 90th Martian day of operations on April 26. A Martian day, or "sol," is 39 minutes and 35 seconds longer than an Earth day.
"Given the rovers' tremendous success, the project submitted a proposal for extending the mission, and we have approved it," said Orlando Figueroa, Mars exploration program director at NASA headquarters in Washington, D.C.
The extension more than doubles exploration for less than a two percent additional investment, if the rovers remain in working condition, NASA said. The extended mission has seven new goals for extending the science and engineering accomplishments of the prime mission, said Naderi at the JPL press briefing.
Spirit is heading to the hills in pursuit of further geological evidence that water once flowed on Mars -- one of the seven objectives for the extended mission. Opportunity has a parallel objective: to seek geologic context for the rocky outcrop in its landing site area, Eagle crater, by reaching other outcrops in Endurance crater 750 meters (2,460 feet) distant, and perhaps elsewhere.
Other science objectives are to continue atmospheric studies at both sites to encompass more of Mars' seasonal cycle and to calibrate and validate data from Mars orbiters for additional types of rocks and soils examined on the ground.
Three new engineering objectives are to traverse more than a kilometer (0.62 mile) to demonstrate mobility technologies; to characterize solar-array performance over long durations of dust deposition at both landing sites; and to demonstrate long-term operation of science robots on another planet.
During the past two weeks, rover teams at JPL , which include several researchers from Cornell, have been switching from living on Mars time to regular Pacific time schedules. The changeover is designed to be less stressful and more sustainable over the longer mission period.
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