Cleaning Event Boosts Spirit’s Power Levels; Oppy Back on the Road

Article written: 12 Feb , 2009
Updated: 24 Dec , 2015

Great news about the both Mars Exploration Rovers! Spirit’s dusty solar panels have been cleaned by a wind event, and Opportunity is back driving again after standing down a few days after a charged particle hit. Sprit’s solar arrays have been extremely dusty ever since a huge dust storm last year enveloped much of Mars, but a dust devil or gust of wind on Sol 1812 (Feb. 6, 2009 here on Earth) has cleaned the panels just enough to make a marked difference in power available to the intrepid rover. Before the event, dust buildup on the arrays had reached the point where only 25 percent of sunlight hitting the array was getting past the dust to be used by the photovoltaic cells. Now, it is up to 28 percent. “It may not sound like a lot, but it is an important increase,” said Jennifer Herman, and engineer for the MER team.

The cleaning boosts Spirit’s daily energy supply by about 30 watt-hours, to about 240 watt-hours from 210 watt-hours. The rover uses about 180 watt-hours per day for basic survival and communications, so this increase roughly doubles the amount of discretionary power for activities such as driving and using instruments. Thirty watt-hours is the amount of energy used to light a 30-watt bulb for one hour.

“We will be able to use this energy to do significantly more driving,” said Colette Lohr, a rover mission manager at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Our drives have been averaging about 50 minutes, and energy has usually been the limiting factor. We may be able to increase that to drives of an hour and a half.”

Spirit has driven about 9 meters (about 30 feet) since getting around a rock that temporarily blocked its progress on Jan. 31. The team’s goal in coming weeks is to navigate the rover over or around a low plateau called “Home Plate” to get to an area targeted for scientific studies on the other side of Home Plate in Gusev Crater.

The last prior cleaning event that was as beneficial as this one was in June 2007. Winds cleaned off more of the dust that time, but a dust storm in subsequent weeks undid much of the benefit.

Opportunity's tracks through the dunes on Mars, on Sol 1791 (Feb 5). Credit: NASA/JPL

Opportunity's tracks through the dunes on Mars, on Sol 1791 (Feb 5). Credit: NASA/JPL

Over on the other side of the planet in Meridiani Planum, Opportunity, drove 135.9 meters (446 feet) on Feb. 10. Opportunity stood down for a few sols as a result of a PMA (Panoramic Mast Assembly) error, due to a SEU (Single-Event Upset), when a charged particle whizzes through a transistor on the rover and flips a bit somewhere inside. “Fortunately, the motor controllers can detect and report these events, so that the rover can safely stop,” rover driver Scott Maxwell told Universe Today on February 5. “We have good reason to hope that Opportunity’s PMA is undamaged and that she’ll be back on the road shortly.”

And now she is back driving to her little heart’s (and the rover drivers’ hearts) content. Opportunity’s cumulative odometry is 14.36 kilometers (8.92 miles) since landing in January 2004, including 2.58 kilometers (1.6 miles) since climbing out of Victoria Crater on Aug. 28, 2008. She is on her way to Endeavour Crater, a huge crater about about 12 kilometers (7 miles) away.

The rovers have been taking a licking, but they still keep on ticking! Over five years now for both rovers –Yippee!

Source: JPL

21 Responses

  1. Tom says

    Awesome! A little less worry about Spirit. Tough little guy keeps going….and going…

  2. robbi says

    With a little TLC, quiet and great companions

  3. Timmy says

    Energizer batteries should just retire that stupid drum-beating rabbit and put the Mars rovers in as their new mascots.

    Even the typical Joe Sixpack can identify the rovers.

  4. H-town Mack says

    We’ll probably put a human on Mars and those things will still be going.

  5. Salacious B. Crumb says

    Perhaps next time, it might be a good idea to take a portable car wash (rover wash?) or windscreen wipers, which can then douse the panels with some fluid or free-flowing solid like graphite to wipe the dust from the little rover.
    Who ever made these two little beasties sure deserve some kind of reward!!

  6. Astrofiend says

    I love these little cleaning events! Just when you think all may be lost; swoosh! …and off they go again.

    The story of these rovers has been simply remarkable. Surely it will have to go down as the most successful space mission ever.

  7. Kevin F. says

    You know, before the rovers landed I calculated how long it would take for the one closest to the Mars Pathfinder lander to get to it to take a picture. It was a figure of many years. I said to a friend “By that time there will be a group of guys in spacesuits applauding as it arrives.”

    Yet I’m shocked that they’re still chugging five years later. Amazing.

  8. Joe Sixpack says

    What’s a rover?

  9. Jenny Sixpack says

    a rover is the thing your meant to be mowing the lawn with! get back to work!

  10. Yan Luz says

    Amazing… Hopefully it can go for a while longer and provide us with more great pictures and information.

  11. Any competent glider pilot will tell you there will be areas on the surface that stimulate what are thermals, updraughts that cause dust devils on the surface. They should plan to seek out such an area for each rover and then park them in that location for long enough to get a good clean of the solar panels. A month parked would be worth the effort of they can achieve the removal of a significant amount of the dust.

  12. Howard Toburen says

    Unless he’s flown gliders on Mars, he wouldn’t be of much use. Especially in the 1% of earth atmosphere. The cleaning effect of a thermal would be pretty much nothing.

  13. Salacious B. Crumb says

    Howard Toburen wrote;
    “Unless he’s flown gliders on Mars, he wouldn’t be of much use. Especially in the 1% of earth atmosphere. The cleaning effect of a thermal would be pretty much nothing.”

    How about instead taking a little gas cylinder like a pressure can of nitrogen. and squirt area of the solar collectors with a very narrow jet. Another could be a tear-off transparent material over the area of the solar panel, a tear off one ever once and a while – just like the Formula 1 drivers do to remove the grease and bugs from their goggles? Just a thought!

  14. Vanamonde says

    Maybe the flattop was not such a good idea? I dunno, best for catching those feeble rays, maybe but our houses do not have flat roofs, especially where it snows a lot. An angle panel might prevent this dust buildup.

    But seriously, it is not like these rover failed to meet their mission requirements! I am so glad Nasa is still working with them way beyond the scheduled stop date!

  15. Will says

    Or, put a “long” box of saran wrap on the edge of one side of the solar panel and a motorized take up reel on edge of the other side. Just reel in the width of the panel when necessary. Repeat as required. lol

  16. Will says

    Now that I think about it, that might just work!

  17. Ignoreme says

    The biggest head slap !Doh! of ever: Forgetting to put wiper blades on the rover’s solar panels!

    Didn’t anyone at Nasa know Mars is really really dusty?

  18. Parahaps says

    They did know, of course. The build-up of dust was figured into the initial estimate of the rovers’ survival time. It was infeasible or impractical to put on wipers or other things for some reason (weight, probably). The cleaning events have been quite fortuitous.

  19. Salacious B. Crumb says

    “Ignore me” said; The biggest head slap !Doh! of ever: Forgetting to put wiper blades on the rover’s solar panels!
    Didn’t anyone at Nasa know Mars is really really dusty?”

    Perhaps instead we should slap you on the head, methinks!

    Clearly no one (including me) expected the rovers to last this long. All bloggers here are suggesting alternatives, and whether they are accepted or not, well really that is up to the agencies. After all, what’s wrong with free thinking?.

    Note: Universe Today is absolutely plagued by this same multiple avatar playing games with everyone’s opinions . Please, do as this pounce seems to wants, and plainly ignore it! I’d suggest ignoramus might be a better avatar. “Destroy me” not likely! MODERATORS PLEASE FIX THIS PROBLEM !!

    Q. Do you monitor IP addresses?

    If not, you should!

  20. RUF says

    The rovers were only to last about 90 days. Therefore, no wipers needed. The fact that they lasted so long is simply stunning.

  21. Ready says

    Lower panels only slightly and vibrate. Using cell phone vibrator. I know hind sight is 20 / 20.

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