Truemors
A dust storm on Mars has cut into the amount of sunlight reaching the solar array on NASA's Mars Exploration Rover Spirit, leaving the rover in a vulnerable state.
Spirit's solar array produced only 89 watt hours of energy during the rover's 1,725th Martian day, which ended on Nov. 9. This is the lowest output by either Spirit or its twin, Opportunity, in their nearly five years on Mars, and much less energy than Spirit needs each day. The charge level of Spirit's batteries is dropping so low, it risks triggering an automated response of the rover trying to protect itself.
"The best chance for survival for Spirit is for us to maintain sequence control of the rover, as opposed to it going into automated fault protection," said John Callas of NASA's Jet Propulsion Laboratory, Pasadena, Calif., project manager for Spirit and Opportunity.
Mission controllers are commanding Spirit to turn off some heaters, including one that protects a science instrument, the miniature thermal emission spectrometer, and take other measures to reduce energy consumption. The commands will tell Spirit not to try communicating again until Thursday. While pursuing that strategy the team also plans to listen to Spirit frequently during the next few days to detect signals the rover might send if it does go into a low-energy fault protection mode.
Mars weather forecasts suggest the dust storm may be clearing now or in the next few days. However, the dust falling from the sky onto Spirit's solar array panels also could leave a lingering reduction in the amount of electricity the rover can produce.
PASADENA, Calif. (AP) — NASA's Spirit rover, which is nearing its fifth year on Mars, is struggling to survive after a dust storm sapped its power, mission scientists said Tuesday.
The solar-powered Spirit produced only 89 watt-hours of energy last weekend, half the normal amount it needs to function. The culprit was a dust storm that moved over Spirit's site near the Martian equatorial plains, blocking sunshine from reaching its solar panels.
To prevent Spirit from depleting its batteries, ground controllers commanded the rover to turn off heaters that warm various instruments. Engineers also instructed the spacecraft to cease communications with Earth until Thursday.
"This is a very dangerous time," said project scientist Bruce Banerdt of NASA's Jet Propulsion Laboratory, which manages the mission. "If we don't hear from it on Thursday, we'll be extremely concerned."
The Spirit news came a day after NASA declared an end to another Mars mission, the Phoenix lander, which lasted five months. Phoenix was parked in the arctic plains and not expected to survive the Martian winter, but a dust storm there hastened its demise.
Scientists said there was reason to hope that Spirit could pull through. The latest Martian forecast suggests the dust storm over Spirit appears to have abated. Spirit's twin, Opportunity, which is exploring on the opposite end of the equator, was not affected by the storm.
Even if the storm passes, there could be damage to Spirit's instruments or a delay in getting the rover moving again if its solar panels remain dusty, Banerdt said.
The deck of NASA's Mars Exploration Rover Spirit is so dusty that the rover almost blends into the dusty background in this image assembled from frames taken by the panoramic camera (Pancam) during the period from Spirit's Sol 1,355 through Sol 1,358 (Oct. 26-29, 2007).
Dust on the solar panels reduces the amount of electrical power the rover can generate from sunlight each sol. Earlier self-portraits by Spirit, such as one taken on Sol 586 (PIA03272), offer a comparison view of cleaner solar panels.
The vertical projection used here produces the best view of the rover deck, though it distorts the ground and antennas somewhat. The eight-pointed star shape near the front of the rover (bottom of the image) marks the location of the camera mast, which is out of view of the Pancam atop the mast.
This mosaic view in approximate true color is a composite of frames taken through the Pancam's filters centered on wavelengths of 600 nanometers, 530 nanometers and 480 nanometers.
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