Posted on by Nancy Atkinson

New Water-Related Discovery from Hibernating Spirit Rover

A mosaic of images shows the soil in front of the Mars Exploration Rover Spirit. Bright-toned soil was freshly exposed by the rover's left-front wheel. The inset show a magnified view of the nearby rectangles within the mosaic, showing the differences between undisturbed and disturbed soil. Credit: NASA/JPL-Caltech/Cornell University

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She may be down, but she’s not out – out of the discovery department, anyway. Data from the Spirit Mars rover – currently in hibernation – shows evidence that water, perhaps as snow melt, trickled into the subsurface fairly recently and may be doing so on a continuing basis.

The area where Spirit became stuck in sandy soil in April of 2009 was churned up by her spinning wheels as engineers at the Jet Propulsion Laboratory attempted to drive her out of a veritable sand trap. This wheel-churning brought subsurface soil layers — which include the water soluble mineral ferric sulfate — up to the surface. Under a thin covering of windblown sand and dust, relatively insoluble minerals such as hematite, silica and gypsum are concentrated near the surface and more-soluble ferric sulfates have higher concentrations below that layer. This pattern suggests water has moved downward through the soil, dissolving and carrying the ferric sulfates.

In combination with another recent discovery — that underground aquifers may have fed ancient seas on Mars — shows a water cycle likely was present in the past on the Red Planet, and may even be present today.

The deputy principal investigator for the Spirit and Opportunity rover, Ray Arvidson and his team say that thin films of water may have entered the ground from frost or snow. (The Phoenix lander saw evidence of current snowfall.) The seepage could have happened during cyclical climate changes in periods when Mars tilted farther on its axis.

“The lack of exposures at the surface indicates the preferential dissolution of ferric sulfates must be a relatively recent and ongoing process since wind has been systematically stripping soil and altering landscapes in the region Spirit has been examining,” said Arvidson.

This isn’t the first time that Spirit’s wheels have churned up interesting stuff. Back in 2008, researchers said Spirit’s bum front wheel uncovered signs minerals that are found in hot springs, similar to what is at Yellowstone National Park on Earth, and similar hot springs may have once bubbled or steamed on Mars.

But there’s been no word from the rover since March 22, 2010, after she went into cold-induced hibernation. Because Spirit was stuck, the rover drivers could not get her in the best position to receive maximum sunlight.

“With insufficient solar energy during the winter, Spirit goes into a deep-sleep hibernation mode where all rover systems are turned off, including the radio and survival heaters,” said John Callas, project manager for Spirit and Opportunity. “All available solar array energy goes into charging the batteries and keeping the mission clock running.”

While she was stuck and still awake, researchers took advantage and examined in great detail soil layers the wheels had exposed, and also neighboring surfaces, making comparisons between the two. While trying to drive back out of her predicament, Spirit made 13 inches of progress in its last 10 backward drives before energy levels fell too low. Those drives exposed a new area of soil for possible examination if Spirit does awaken and if its robotic arm is still usable.

However, it is thought that the aging Spirit rover experienced the coldest temperatures ever, and it may not survive. Everyone is still holding out hope that the rover may yet make contact through one of the orbiting spacecraft and the Deep Space Network.

If Spirit does get back to work, the top priority is a multi-month study that can be done without driving the rover. The study would measure the rotation of Mars through the Doppler signature of the stationary rover’s radio signal with enough precision to gain new information about the planet’s core.

Meanwhile, over on the other side of Mars, the rover Opportunity has been making steady progress toward a large crater, Endeavour, which is now approximately 8 kilometers (5 miles) away.

The newest findings were published in the Journal of Geophysical Research.

Source: JPL

Posted on by Nancy Atkinson

NASA Braces Rover Fans for the Worst About Spirit

Spirit rover, as seen by HiRISE on Feb. 15, 2010. Crop and colorization by Stuart Atkinson, image credit: NASA/JPL, U of AZ

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JPL issued a press release today with an update that mission controllers have still not heard from the hibernating Spirit rover. Even though the rover is experiencing one of Mars’ harshest winters since the rovers arrived, the rover team has begun an active “paging” technique called ‘sweep and beep’ in an effort to communicate with Spirit instead of just passively listening for any activity from the rover. Based on models of Mars’ weather and its effect on available power, mission managers believe that if Spirit responds, it most likely will be in the next few months. But in a ‘hope for the best, prepare for the worst’ kind of way, the press release added, “However, there is a very distinct possibility Spirit may never respond.”

“It will be the miracle from Mars if our beloved rover phones home,” said Doug McCuistion, director of NASA’s Mars Exploration Program. “It’s never faced this type of severe condition before – this is unknown territory.”

The Martian winter runs from May through November here on Earth, so there’s still a lot of long, dark winter to get through. Spirit has not communicated since March 22, 2010 and is likely in a low-power hibernation mode since the rover was not able to get to a favorable slope for its fourth Martian winter. The low angle of sunlight during these months limits the power generated from the rover’s solar panels. During hibernation, the rover shuts down communications and other activities so available energy can be used to recharge and heat batteries, and to keep the mission clock running.

On July 26, rover engineers began the sweep and beep. “Instead of just listening, we send commands to the rover to respond back to us with a communications beep,” said John Callas, project manager for the rover. “If the rover is awake and hears us, she will send us that beep.”

The earliest date the rover could generate enough power to send a beep to Earth was calculated to be around July 23. However, mission managers don’t anticipate the batteries will charge adequately until late September to mid-October.

So, there is still a lot of time to wait things out. While I don’t think the rover team is giving up on Spirit at all, it appears they want to prepare the rover faithful for the worst.

But I’m going to make a prediction here: not only will Spirit wake up, but the rover driving team will be able to get her out of the sand trap she is stuck in. Just a hunch, but you heard it here and only time will tell if my prediction comes true.

Based on previous Martian winters, the rover team anticipates the increasing haziness in the sky over Spirit will offset longer daylight for the next two months. The amount of solar energy available to Spirit then will increase until the southern Mars summer solstice in March 2011. JPL says that if we haven’t heard from Spirit by March, 2011 it is unlikely that we will ever hear from it.

Leave it to Steve Squyres, however, principal investigator for the rovers, to leave us with a little hope: “This has been a long winter for Spirit, and a long wait for us,” he said. “Even if we never heard from Spirit again, I think her scientific legacy would be secure. But we’re hopeful we will hear from her, and we’re eager to get back to doing science with two rovers again.”

Source: JPL

Posted on by Nancy Atkinson

Wind Gust Gives Opportunity Rover a Power Boost

The Opportunity rover's solar panels got a cleaning sometime between Sol 2274 and 2299. Credit: NASA/JPL, collage and annotation by Stu Atkinson.

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Either some little Martians came by and gave the Opportunity rover a quick once-over cleaning, or a recent gust of wind blew layers of dust off her solar panels. The image above (supplied by our favorite photo- whiz Stu Atkinson), shows Oppy’s solar panels on sol 2274 and 2299 (approximately June 18 and July 12 here on Earth) with a marked difference in the amount of dust on the panels. Yesterday, the Twitter account for the rovers, @marsrovers Tweeted: “Love those Martian dust busters! A recent wind gust cleaned Oppy’s solar panels giving her a little power boost for the road.” And on the road she is, heading earnestly for Endeavour Crater, with several recent drives of around 70 meters (230 feet) per sol. But she now has some new autonomous software the rover team is trying out, and with her new greater power capacity, she should be able to keep on truckin’. Mars rover driver Scott Maxwell reported on Twitter this week that Opportunity is 40% of the way from Victoria Crater to Endeavour.

And what’s the latest news about Spirit – still silent?

According to Maxwell (again on Twitter), the power models for sunlight hitting Gusev Crater say the very earliest we could possibly hear from Spirit could be sometime late this week. But he added that more likely would be hearing from Spirit by around mid-November.

But catching Spirit awake is complicated, with timing being everything. “Even if Spirit’s waking up (soon), we’ll have a hard time catching her during one of her wakeups,” Maxwell said. “This will take some luck as well as skill,” having the Mars Reconnaissance Orbiter or Mars Odyssey overhead and listening at the very moment Spirit is talking. Maxwell added that the team is working on how to locate Spirit if she’s had a Mission Clock fault and doesn’t know how to send communications to Earth.

It is very likely that Spirit has experienced a low-power fault and has turned off all sub-systems, including communication and gone into a deep sleep. While sleeping, the rover will use the available solar array energy to recharge her batteries. When the batteries recover to a sufficient state of charge, and if the Mission Clock hasn’t gone completely bonkers, Spirit will wake up and begin to communicate.

Spirit’s odometry remains at 7,730.50 meters (4.80 miles).

But meanwhile, Oppy’s total odometry is 21,550.77 meters (21.55 kilometers, or 13.99 miles), and she’ll be putting on more as she heads towards Endeavour Crater. Maxwell later said he has an idea to speed up the rover’s drives as much as 30%, so that will be interesting to find out more about his idea. “A 30% speedup would shave 2-3 months off our trip to Endeavour — maybe even more than that. Worth a try! Phyllosilicates, here we come!,” he tweeted, referring to the water-based minerals that scientists are hoping to find within the crater. That would mean water helped form the rocks in Mars’ early history.

Features on Endeavour Crater named for Australian locations. Image Credit: NASA/JPL-Caltech/Cornell University

Speaking of Endeavour, recently, NASA and JPL released an image showing the newly-given names of different points on Oppy’s next destination, and there’s a push by some people in Australia for one additional feature to be named “Nobby’s Head.”

The rover team is using the theme of names of places visited by British Royal Navy Capt. James Cook in his 1769-1771 Pacific voyage in command of H.M.S. Endeavour. My friend Col Maybury from radio station 2NUR in Newcastle, New South Wales, Australia is helping to promulgate this request to NASA, with the support of the Minister of Tourism and Newcastle’s Lord Mayor. “Hopefully we will get a favourable reply soon,” Col wrote me.

Cook first came to this location in May of 1770. At midnight by moonlight he saw an island jutting up from the sea and wrote in his journal: “A small round rock or Island, laying close under the land, bore South 82 degrees West, distance 3 or 4 Leagues.”

Now called Nobby Head, it is the entrance of Newcastle Harbour, formed by the Hunter River, a great coal port of New South Wales. The feature on Mars is the same shape as Nobby Head on Earth. Wish Col and the people of Newcastle good luck in their “endeavour” to name this feature! (Anyone from the rover team naming committee reading this?!)

The proposed Nobby's Head at Endeavour Crater on Mars. Credit: NASA/JPL, annotation by Col Maybury.

And don’t forget, Friday July 16 is Mars Day! The National Air and Space Museum has some ideas on how to celebrate.

Posted on by Nancy Atkinson

Spirit Rover Still Providing New Evidence for Past Water on Mars

Seen close up, the Comanche outcrop shows both a granular texture and multiple layers. Scientists think it is volcanic debris draped over preexisting terrain. After it was deposited, the rock was soaked in hydrothermal water rich in carbonate minerals. False-color Pancam image. Credit: NASA/JPL/Cornell University

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Even though the Mars Rover Spirit is asleep, a new look at old data from one of her instruments confirms the presence of large amounts of carbonate-rich rocks, which means that regions of the planet may have once harbored water. The Miniature Thermal Emission Spectrometer, or Mini-TES, instrument on the rover looked at an outcrop of rocks called “Comanche” back in 2005, but the instrument was partially “blinded” by dust. Only when scientists developed a special calibration to remove the spectral effects of the dust on the instrument was the spectral data revealed to show evidence for carbonate-rich outcrops in a range of low hills inside Gusev crater on Mars.

Spirit has gone into hibernation because of low power levels during the extremely cold winter months on Mars. She is stuck in some loose sand in the Home Plate region, and the rover teams were unable to get her solar panels in a good position to soak up the sun’s energy.
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See more images of Comanche, below, courtesy of Stu Atkinson.

Carbonates are clues to neutral pH conditions, and the mineral forms readily in the presence of water and a carbon dioxide atmosphere. If conditions were right for carbonate-bearing rocks to form, water would have been present, and could have created an environment favorable to life. Yet until now, geologic clues for the presence of carbonates on the surface of Mars have been scarce.

“Mini-TES got dusted months before Spirit reached Comanche, and we didn’t have a good way to correct for the dust effects at the time,” said Steve Ruff, research scientist at Arizona State University’s Mars Space Flight Facility. Ruff is one of a team of scientists on the paper, whose lead author is Richard V. Morris of NASA’s Johnson Space Center in Houston. “We knew there was something weird about the outcrop’s spectrum as seen by Mini-TES, but couldn’t say what caused it.”

Ruff said that even though Spirit’s Mössbauer spectrometer indicated that carbonate was possible, the team needed more evidence to be convinced. When the calibration method to remove the spectral effects of the dust made that data available, and combined with chemical data from a third spectrometer, “the Mini-TES spectra put the discovery over the edge,” Ruff said.

Scientists have been searching for Martian carbonate rocks for decades because such minerals are crucial to understanding the early climate history of Mars and the related question of whether the planet might once have held life.

Part of the Pancam “Seminole Panorama” taken near the Seminole outcrop on the southeast slope of Husband Hill. Home Plate and the Comanche outcrops are visible in this image. Image courtesy of NASA/JPL/Cornell. http://pancam.astro.cornell.edu Image captions

Small amounts of carbonate minerals have been detected on Mars before, but Ruff said this new data is different. “We’re seeing a couple of large outcrops of rock poking through the soil of the Columbia Hills,” he said. “The rocks are about 25 percent carbonate by weight, by far the highest abundance we’ve seen on Mars.”

The mineral is rich in magnesium and iron and possibly formed a long time ago by precipitation from the hot, residual waters from leftover magma that flowed through buried carbonate deposits.

NASA’s other Mars rover, Opportunity, has discovered ample evidence for alteration of rocks by water in Meridiani Planum, on the other side of Mars from Spirit’s Gusev Crater. But the water at Meridiani was strongly acidic. While life can evolve to survive in acidic conditions — such as in some of Yellowstone National Park’s geysers and hot springs — few scientists think it can start under those conditions.

Moreover, acidic water quickly destroys carbonate minerals, as for example vinegar dissolves hard water deposits. Thus finding outcrops of carbonate rock shows that the hydrothermal water at Comanche was liquid, chemically neutral, and abundant.

While there’s no evidence for life, Ruff says, the conditions would have been more favorable for it.
Ruff added that more old data from Spirit could hold new clues to Mars’ past. “The Comanche data have been available to scientists and the public for about four years now. The new finding shows that this data set still harbors potentially major discoveries.”

Source: ASU

More images of Comanche, rendered by Stu Atkinson:

Panorama of the Comanche outcrop. Credit: NASA/JPL, rendered by Stuart Atkinson.
Another color view of Comanche. Credit: NASA/JPL, colorization by Stuart Atkinson.
D view of Comanche. Credit: NASA/JPL, 3-D by Stuart Atkinson
Posted on by Nancy Atkinson

HiRISE Captures Amazing Close-Up of Spirit Rover

Spirit rover, as seen by HiRISE on Feb. 15, 2010. Crop and colorization by Stuart Atkinson, image credit: NASA/JPL, U of AZ

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The HiRISE team released some new images on Wednesday — one of which was another incredible avalanche image. But then there was another shot of Gusev Crater, the home of the Spirit rover. It was a wide shot of the entire region (you can see it below), and visible are the Columbia Hills, and if you look real close you can see the “Home Plate” region where Spirit sits. Our friend Stu Atkinson took a real close look and found Spirit sitting all alone –but very visible in this wonderfully amazing zoom-in closeup! (Click the image for access to a larger version). Stu also colorized it to show almost intricate detail of Spirit’s solar panels. The image was taken on Feb. 15, 2010, and she looks great! She’s in her current stationary position, and even though this image is from before she went into hibernation, it’s great to know she’s still sitting there, waiting for warmer days. “Hang in there rover, hang in there…” Stu said on Twitter, which echoes all our sentiments. Awww, Spirit….

Thanks to Stu and HiRISE for keeping our hopes alive!

The Spirit rover landing region. Credit: NASA/JPL/University of Arizona

Stu has also written a few of wonderful items about Spirit: A poem called Spirit Shivering, a great story about someone who maybe could travel to Mars and free Spirit, and a great blog post titled, “Spirit, Time to Rest.” Stu is a very talented writer and image editor, so check out his incredible handiwork!

Posted on by Nancy Atkinson

Movies of Spirit’s Last Moves Before Winter

Even though the Spirit rover is stuck in a Martian sandtrap, the rover drivers were actually able to move her quite a bit, and therefore improving her chances of surviving the winter. This video shows recent drives by the Spirit rover from Jan. 14 to Feb. 4, 2010 (Sols 2145 to 2165), where the center of the rover approximately 13.4 inches (34 centimeters) backwards. Since Jan 26 (sol 2157), drive commands have concentrated on placing Spirit into a favorable tilt toward the sun as the Martian winter approaches.

Posted on by Nancy Atkinson

Can an Immobile Spirit Rover Survive the Martian Winter?

Mission managers for the Mars Exploration Rover program announced this week that the Spirit rover will likely never rove again on Mars. But that doesn’t mean her life is over. However, with the rover virtually immobile and stuck in a sand trap, she currently is in a very vulnerable and potentially “deadly” situation as winter approaches on Mars’ southern hemisphere. Pointing the rover’s solar panels towards the sun is critical if the rover is to survive, and the rover team has just a handful of drives to make it so. And the winters are long and harsh on Mars. “The temperatures will be colder than anything Spirit has experienced before,” said John Callas, project manager for the MER mission. “This is a much more difficult and dangerous situation for Spirit, and we’re heading into a regime where vehicle is going to get colder than it ever has.”

What is Spirit facing, and what are her odds?

“Spirit will be experiencing decreasing power levels, and we will likely see energy levels that will drop below 160 watt hours,” said Callas, which is the level of power the rover needs to maintain so it can communicate daily with Earth. “If we can’t maintain that level, that will trip a low power fault where the rover shuts down or hibernates, taking the necessary steps to preserve as much power as possible. Everything is turned off except the master clock, and all the photons that hit solar arrays go into charging the batteries.”

In this low-power fault, a timer wakes the rover up occasionally to check battery levels, and if there is enough power, Spirit will wake up enough to see how charged the batteries are and attempt to communicate with Earth. “Spirit will be like a polar bear hibernating, possibly for several months, maybe on the order of 6 months that the rover will be in this state,” said Callas. “It won’t be like the Phoenix lander where it shuts down virtually completely. The rover will still be electrically active, but not with enough power to be awake each day.”

Callas predicted it will be in the March-April time frame here on Earth when they run out of ability to communicate with rover because there won’t be enough power.

Normally the rover stays warm enough simply by being “on” and running, like running your car in the winter to warm it up. But since rover will be deeply sleeping, temperatures on the rover will drop.

Callas and his team are concerned that temperatures on the rover will get very cold. Based on past winters, they expect about -40 to -50 C temperatures on Mars during the depths of winter. The electronics on the rover can withstand -40 degrees C when operating and -50 c when the rover is idle. But these standards are for a brand-new out-of-the-box rover, Callas said, not a 6 year-old rover with electronics have gone through many different temperature cycles.

Ironically, the fumaroles or steam vents that likely created the very scientifically rich “Troy” area where Spirit sits would have made it a “hot spot” on Mars. But, of course, the fumaroles are no longer active.

The rovers do have three 1-watt Radioisotope Heater Units (RHUs) which are tiny thermal heating units used to keep motors and batteries warm on the rover, so Spirit’s important insides will not get as cold as the outside.

But power from the solar panels is very important for keeping the computer and other electronics active, and right now, the position of the solar panels is not at all optimal.

“Our primary mission is to get solar panels pointed toward sun improve her chances,” said rover driver Ashley Stroupe. “Ideally the solar panels should be pointed toward the sun, to maximize the energy the rover receives. If we can get enough power to keep the rover warm, that will shorten the amount of time Spirit may have to be in a low power state.”

In upcoming drives, the team will try to get left rear wheel of the rover lifted up, by driving backward and improving its northerly tilt. Spirit is sitting in a small crater with the rim behind her, so as it moves backwards, it is slowly climbing up on the rim, tilting the rover. “On the last drive we saw 1-2 degree improvement in tilt,” Stroupe said on Tuesday. “So we’re going to do as much improvement as we can by continuing to drive backward. We can an also attempt to rotate the rover in place, so that the roll isn’t pointed as much towards the south as it is now.”

The Spirit rover's solar panels were covered with dust until a gust of wind blew it off. Credit: NASA.

Each degree of tilt towards the north gains 5 watt hours of improvement. One upside is that the solar panels are currently fairly free of dust accumulation.

When the rover attempts to wake up each day, it will be at about noon local time on Mars, when the electronics will have warmed up because of sunlight.

But there’s the possibility the team might not hear from the rover for months.

“We have to be prepared to go through a period like this,” said Callas. “We may not hear from rover, and it will be frustrating and challenging for the team, but we’ll have to be disciplined about this, and hopefully when power resumes we can resume communication in the spring.”

A look at the nearly buried wheels on the Spirit rover on Mars. Credit: NASA/JPL

And, worst case scenario, where is a very long period of time where they don’t hear from the rover, how long will the team attempt to communicate with Spirit?

“That’s a very complex problem,” Callas told Universe Today at the Tuesday’s press conference. “The rover will actually experience two levels of fault protection. The rover takes action based on hearing from Earth, and if we go too long without talking to the rover, it trips an up loss timer. We only keep about 6 weeks of communication tables on the rover, so that likely will have run out. All these things make for a complex recovery effort for the rover. It is hard to say how long we would try, because we would have to try many things before we exhaust the list of things we can do.”

Callas didn’t want to give odds if Spirit will make it through the winter. “Spirit’s best chance for survival is when we can stay in contact with her,” he said. “As long as we can maintain communication with rover we can look out for trouble, and advise her on how to best reapportion her limited resources.”

MER PI Steve Squyres said not having a roving rover is a “poignant moment” for the team. “We built the rovers to drive around, so we have shifted our focus to a different class of activities. It is a change and one we’ll have to adapt to. But this is a much better way that having an abrupt end to the mission, which would preclude doing the kind of science we’re looking forward to.” (Read more about the science Spirit can do in our earlier article)

“We have hope that Spirit will survive this cold dark winter that Spirit has ahead of her,” Squyres said.

Posted on by Nancy Atkinson

No More Roving for Spirit; Stationary Science Ahead

Mars Exploration Rover Mission
Artist concept of the Mars Exploration Rover on Mars. Credit: NASA

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The Spirit rover’s driving days are likely over, as efforts to extricate the rover have been curtailed. “We do not believe that Spirit is extractable,” said Doug McCuistion, director of NASA’s Mars Exploration Program. But mission managers stressed that today is not a day of loss at this point, as they hope to continue to make some exciting scientific observations. However, the rover needs to be tilted to gather as much sunlight as possible in order to survive the Martian winter. John Callas, project manager for the MER mission told Universe Today at today’s press briefing that time is short. “We estimate about three weeks of driving activity, and we can’t drive every day,” he said. “So there are just a handful of drives left before there is insufficient power to continue.”

Callas added that around the March-April time frame will be the last images and data the rover can transmit before going into hibernation for the winter.

Spirit has been embedded in a sandtrap for 10 months, and the rover team has been engaged in an ambitious process to extricate the rover. They’ve encountered numerous setbacks, including the loss of use of an additional wheel, making it a four-wheeled rover. (Spirit’s right front wheel has not worked for a couple of years, now the right rear wheel has lost functionality).

A look at the nearly buried wheels on the Spirit rover on Mars. Credit: NASA/JPL

“Spirit is in a golfer’s worst nightmare, stuck in a sand trap that no matter how many strokes you take you can’t get out of,” said McCuistion.

Pointing the rover’s solar panels towards the sun is critical if the rover is to survive. In past winters, the movable rover has been able to be positioned to allow for maximum sun-gathering but the current embedding of the rover has left it with an unfavorable tilt, 9 degrees to south, when they really want a level rover — or even better — tilted to north.

Rover driver Ashley Stroupe said the rover is now pitched flat and rolled to left. “We want to try to pitch it forward and roll right for best winter survival.”

The last few drives were aimed at trying to improve the rover’s position, and were mildly successful.

“We’ve aimed toward improving northerly tilt,” said Stroupe. “Spirit is sitting in a small crater with the rim behind her, so as it moves backwards, it is slowly climbing up, providing more tilt. On the last drive saw 1-2 degree improvement in tilt.”

In recent drives, the rover has moved approximately 20 centimeters. The team can also attempt to rotate the rover in place, so that the roll isn’t pointed as much towards the south as it currently is.

Mosaic of the area called Home Plate where Spirit remains stuck was made especially for Spaceflight Now, and is used by permission. It shows smooth area, foreground, that concealed slippery water related sulfate material where rover became stuck. Credit: Kenneth Kremer, Marco DiLorenzo, NASA/JPL/Cornell/Spaceflight Now

Should they be successful, and if the rover survives the winter, the science team has some exciting prospects of continuing science with Spirit.

“We have hope that Spirit will survive this cold dark winter that she has ahead of her,” said MER principal investigator Steve Squyres. “The bottom line is we’re not giving up on Spirit.”

Squyres said they are most excited about tracking the radio signal from Spirit in order to determine if Mars has a solid or liquid core. “This is something totally new, something we’ve never done,” Squyres said. “If we can accurately determine the rover’s motion in space in three dimensions, we can see the motions of Mars in orbit and track it precisely, then we can characterize the wobble very precisely. The way Mars wobbles depends on its internal structure. If Mars has a solid core of iron, will wobble one way but if it has a liquid molten core it will wobble another way. We should be able to do this by tracking the stationary rover for six months.”

Squyres said the team is finding new tricks on how to use a stationary rover. Additionally, they should be able to characterize the odd soil at the Home Plate region, and characterize the interactions between the atmosphere and the surface of Mars.

“We’re not giving up on Spirit and we’ll keep squeezing as much science out of the rover as we can,” Squyres said. “We feel there is a lot of really exiting science yet ahead.”

Source: Press briefing

Posted on by Nancy Atkinson

Will the Spirit Rover Survive 2010?

Will Spirit have a happy 2010? Let's hope so! Image created by Stu Atkinson.


In just a few days, the Spirit rover will celebrate six incredible years on Mars. But JPL put out a press release today, as well as the video above, saying the outlook for Spirit’s survival is not good. Being stuck in a sand trap with wheels that aren’t working well are challenges to Spirit’s mobility that could prevent the rover team from using a key survival strategy — positioning the rover’s solar panels to tilt toward the sun to collect power for heat to survive the severe Martian winter. “The highest priority for this mission right now is to stay mobile, if that’s possible,” said Steve Squyres, principal investigator for the rovers.

I’m still holding out hope, however, that the rover team will work another miracle, and that 2010 will be another happy year for Spirit on Mars — see the image below created by Stu Atkinson.

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But if mobility is not possible, the next priority is survival. To to that, the rover team will attempt to improve the rover’s tilt, while Spirit is able to generate enough electricity to turn its wheels. Spirit is in the southern hemisphere of Mars, where it is autumn, and the amount of daily sunshine available for the solar-powered rover is declining. This could result in ceasing extraction activities as early as January, depending on the amount of remaining power. Spirit’s tilt, nearly five degrees toward the south, is unfavorable because the winter sun crosses low in the northern sky.

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.

“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,” said Jennifer Herman, a rover power engineer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

The team is evaluating strategies for improving the tilt even if Spirit cannot escape the sand trap, such as trying to dig in deeper with the wheels on the north side. In February, NASA will assess Mars missions, including Spirit, for their potential science versus costs to determine how to distribute limited resources. Meanwhile, the team is planning additional research about what a stationary Spirit could accomplish as power wanes.

“Spirit could continue significant research right where it is,” said Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the rovers. “We can study the interior of Mars, monitor the weather and continue examining the interesting deposits uncovered by Spirit’s wheels.”

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.

Source: JPL

Posted on by Nancy Atkinson

Old Gimpy Wheel on Spirit Rover Shows Signs of Life

Could it be true that the old gimpy wheel on the Spirit rover is making a comeback? The right-front wheel, which stopped operating way back on Sol 779 (March 13, 2006), surprised engineers by indicating normal resistance and turning slightly during a resistance test for that wheel. Spirit, which has been stuck in soft soil for several months, recently got bad news that the right rear wheel also stopped working (Nov. 21), leaving her with just four of six wheels operational. Engineers conducted tests on Dec. 12 and the right rear wheel continued to show no motion and exhibited very high resistance in the motor winding. Just for fun (I’m assuming) engineers also test the right front wheel – the wheel that Spirit has limped with in coming down from the top of Husband Hill and making the trek across Gusev Crater to the Home Plate region where she currently sits. In surprises of all surprises, the old gimpy wheel showed signs of life.

Diagnostic tests were run on Spirit’s right-rear wheel and right-front wheel on Sol 2013 (Dec. 12, 2009). The recently stalled right-rear wheel continued to show no motion. Engineers expected nothing from the right front wheel. The last time it was checked was just after its apparent failure in 2006 and at that time indicated an open circuit. JPL says that although no clear theory for failure had been established, the failure was generally regarded as permanent.

JPL also says it is important to remember that the Sol 2013 test of the right-front wheel was only a rotor resistance test, and no conclusions can be drawn at this point without further testing.

The plan for Spirit on Sol 2116 (Dec. 15) is to command a drive, which will test the functionality of both the right-front and the right-rear wheels. The results are expected Wednesday.

Spirit continues to surprise….stay tuned!