Spirit rover clocks up six years on Mars
Still battling on from Red Planet sand trap
NASA's Spirit Mars rover today passes its sixth anniversary on the Red Planet, albeit bogged down in sandy soil which looks likely to be its final resting place.
Spirit arrived on Mars at 8:35 pm PST on 3 January, 2004 (04:35 GMT on 4 January), followed by its twin Opportunity on 24 January. The pair were intitially expected to last three months, but have proved they have the Right Stuff by surviving "six Earth years, or 3.2 Mars years", as NASA puts it.
However, Spirit got stuck in a sand trap dubbed "Troy" in Mars's southern hemisphere back in April. Having already suffered a right-front wheel failure in 2006, its right-rear wheel then succumbed to intermittent failure. NASA explains: "Drives with four or five operating wheels have produced little progress toward escaping the sand trap. The latest attempts resulted in the rover sinking deeper in the soil." (see pic*)
The agency is still hoping to extract Spirit, but if that's not possible, it will attempt to "improve the rover's tilt, while Spirit is able to generate enough electricity to turn its wheels".
Unless Sprit can angle its solar arrays to capture the maximum possible sunlight, it faces the prospect of freezing to death when winter arrives in five months, since it won't be able to power the internal heaters which protect its electronics. NASA explains that the current tilt is "nearly five degrees toward the south", which is "unfavorable because the winter sun crosses low in the northern sky".
Accumulated dust on the arrays may also speed the rover's demise. Jennifer Herman, a rover power engineer at NASA's Jet Propulsion Laboratory in Pasadena, said: "At the current rate of dust accumulation, solar arrays at zero tilt would provide barely enough energy to run the survival heaters through the Mars winter solstice."
NASA glumly admits: "Unless the tilt can be improved or luck with winds affects the gradual buildup of dust on the solar panels, the amount of sunshine available will continue to decline until May 2010. During May, or perhaps earlier, Spirit may not have enough power to remain in operation."
However, the rover team is hoping that Spirit's mission is not yet done and dusted. Ray Arvidson of Washington University, deputy principal investigator for the rovers, offered: "Spirit could continue significant research right where it is. We can study the interior of Mars, monitor the weather and continue examining the interesting deposits uncovered by Spirit's wheels."
NASA concludes: "A study of the planet's interior would use radio transmissions to measure wobble of the planet's axis of rotation, which is not feasible with a mobile rover. That experiment and others might provide more and different findings from a mission that has already far exceeded expectations." ®
* NASA's caption explains: "Spirit attempted to turn all six wheels on Sol 2126 (Saturday, Dec. 26, 2009) to extricate itself from the sand trap known as "Troy," but stopped earlier than expected because of excessive sinkage. Telemetry indicates that the rover moved forward 3 millimeters (0.12 inch), left 2 millimeters (0.08 inch) and down (sinkage) 6 millimeters (0.24 inch). The right-front and right-rear wheels did not move."
Wrong type of sand?
"Telemetry indicates that the rover moved forward 3 millimeters (0.12 inch), left 2 millimeters (0.08 inch) and down (sinkage) 6 millimeters (0.24 inch). The right-front and right-rear wheels did not move.""
So about the same amount of movement achieved by some British drivers when there is more than 2cm of snow on the ground.
Something to admire
Whichever way you look at it these martian rovers have been an outstanding achievement, lasting 6 years when the original plan was 3 months. I wish they build cars with so much reliability.
I expect that these rovers will eventually become prime museum exhibits, possibly back here on earth, when man is able to get to and from Mars reliably. When that might be I couldn't say, but by the end of the current century might be feasible if we stop wasting money on invading and occupying foreign countries on some pretext of enhancing our security, and put the money to good use instead.
Paris because the word 'invasion' conjures up thoughts that as a happily married man I really shouldn't be having.
The Rover chassis has proved to be an excellent design but maybe some new tools would be nice.
Something (laser maybe) to vaporize rock, and a Mass Spectrometer would be nice. The mass spec could also sample the atmosphere to see where the methane is coming from. Above all, now we know the platform can last as long as the solar panels stay free of dust, let's add a feather duster.