Spirit Rover in Trouble
Written by Nancy Atkinson
Martian dust storms are wreaking havoc with human spacecraft. Not only did a dust storm cut short the Phoenix lander's extended mission, but now, another dust storm around Gusev Crater has cut into the amount of sunlight reaching the solar array on Spirit, one of the Mars Exploration Rovers, leaving the rover in serious trouble from diminished power. From the image above, it's obvious Spirit's solar panels are thickly coated with dust. Although this image was taken over a year ago, it's likely the solar panels have only gotten worse.
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.
We'll keep you posted on Spirit's condition.
Source: JPL
Related stories on Universe Today
Comment policy: Be nice and brief. Don't advertise your stuff, or promote your personal theories. We'll delete any comments that break these policies. Click here for more details.
November 11th, 2008 at 6:07 am
Note to NASA: Someone please design some fuzzy windshield wipers for future panels.
November 11th, 2008 at 6:08 am
Where are the wiper blades?
November 11th, 2008 at 8:21 am
Or start sending stuff powered by RTGs.
November 11th, 2008 at 8:24 am
really, you'd think an organization that can build two geologists on wheels, land them both on a dusty rock some thirty million miles away, and keep them running over four and a half years past their designed life expectancy would realize that a solar powered machine is going to encounter some dust and maybe build in some counter measures…or not…
November 11th, 2008 at 8:27 am
i think RTGs might be difficult to build on such a small scale, also if you have an incident on launch of a craft with an RTG, there is the possibility of widespread poisoning within a certain radius of the launch site.
November 11th, 2008 at 9:30 am
Well, considering they are WAY past their 90 Warranty, I suppose the fact that they have lasted long enough to get DUSTY pretty much kicks ass. It's especially novel that we have a pair of these things up there and they BOTH keep working, The designers could make a killing if they got this sort of result from a standard automobile.
November 11th, 2008 at 10:37 am
We need another good dust devil!
November 11th, 2008 at 10:48 am
RTGs are becoming smaller, safer, and more efficient, as the next generation of RTG will be installed to the New Mars Science Laboratory.
RTG casings are designed for atmospheric reentry, as the Apollo 13 accident represents an extreme scenario due to the high re-entry velocities of the lunar module returning from cislunar space.
Subsequent investigations have found no increase in the natural background radiation in the area. This accident has served to validate the design of later-generation RTGs as highly safe.
November 11th, 2008 at 12:29 pm
Then I guess the two Viking landing sites are now biohazard zones?
They did not put "wiper blades" on the rovers because that was just one more device that would consume power and ultimately break down. Besides, for a while the dust devils were a nice surprise in cleaning them off.
How much more science can Spirit do anyway even without the dust on it?
November 11th, 2008 at 1:03 pm
I was thinking the same thing.
Why they haven't thought of a windshield wiper….?
If nuclear power technology wasn't an option in the table then,
They could have use some simple fluffy blades or electrostatically ionize the dust over the panel and remove them with a biased negative electrode.
November 11th, 2008 at 2:32 pm
Hopefully they are antifreeze and streak-resistant wipers.
November 11th, 2008 at 2:49 pm
A small fan ?
Anyway, the little chaps are troopers, have served humanity over and above the call, have produced, and continue to produce some stunning pictures, and I for one, as an oldie who will unfortunately never set foot on another planet, think the designers, support crews, engineers and all involved deserve some hearty congratulations for keeping them going this long ! ( Is Spirit the one dragging a wheel ? or s that opportunity ? )
Cheers to the rovers!
November 11th, 2008 at 3:52 pm
What I don't understand is how something as dusty as that image above could possibly be using solar power NOW.
November 11th, 2008 at 4:08 pm
"Why they haven't thought of a windshield wiper….?"
I keep hearing this stuff everywhere.
Guys, the MER's were only designed to work for 90 days! They didn't plan, nor need to plan, for a five year mission. If they knew that Spirit would last this long, they probably would have given it something to clean itself with.
Also, RTG's aren't practical on a 90-day mission, so they weren't included.
It's like packing enough food for a week-long vacation, and getting stuck there for a month. You're hungry? Why didn't you bring more food?
November 11th, 2008 at 6:42 pm
They worked for well beyond the 90 day warranty, and that is simply amazing. Our hats should rightfully be off to all the people that made these missions possible.
…But having said that, we now know to expect more out of small packages. We've also been on mars long enough to have an idea of what it can throw at our machines.
So dust countermeasures (among other things) should become part of the plan on future missions.
November 11th, 2008 at 8:08 pm
how did they managed to snap the picture of spirit?is this computer generated or the real picture?
November 11th, 2008 at 10:18 pm
sbuf – The camera is up high (about 5 ft off the ground) on a mast. It can look down and pan around to take a complete 360 of the spacecraft. Mind you, it takes several pictures and lots of downloading to get an image like this one.
November 12th, 2008 at 2:03 am
12 months old! Surely there is a more recent image.
November 12th, 2008 at 4:46 am
Simple Problem, Simple Solution.
Land some humans on Mars and they can clean the dust off.
November 12th, 2008 at 8:34 am
I have the highest admiration for the countless NASA engineers and scientists who put these rovers on Mars and maintain them. However, I've always suspected the 90-day warranty period was very conservative. I've noticed this on other missions as well. I think the space agency does this to allow itself a cushion of protection against failure. If you'd ask these scientists in private most would've admit it was expected for these brave little machines to last at least a martian year. Just my opinion.
November 12th, 2008 at 11:28 am
I asked about a windshield wiper a few years ago and heard that the reason was that it would add extra weight but what I don't understand is why they don't just instruct the solar panels to partially fold up (as they were during transit to Mars). At some point the panels would be vertical and wouldn't the dust just drop off? They can then reopen them. Maybe it would be dangerous in case there was a problem but if the rover is about to die what's there to lose?
November 14th, 2008 at 4:37 pm
I wonder if the reason they didn't design something to protect from the dust is because they never expected the rovers to last long enough to need said system? I know they expected longer than 90 days, but who expected longer than 300 days?