Mars Express Maps Aurorae

If you’ve been lucky enough to ever see the aurorae (or Northern Lights) on Earth, I’m sure you’ll remember it as a spectacular sight. Fortunately, this phenomenon is not unique to the Earth: Venus, Jupiter, Saturn and Mars all have their own unique auroae, and none of them would appear to a Martian or Venusian like those of our own planet.The SPICAM instrument aboard Mars Express first observed an auroral emission event in 2004, and has since been training its UV eyes on the planet, observing a total of nine events since.

Aurorae are created by the interaction of electrically charged particles with the atmosphere of a planet. The solar wind is made up of these charged particles, and when they pass near an orbiting planet, the magnetic field channels them along its field lines (in the case of the Earth, this occurs near the poles). When the interaction occurs, light is emitted, whether it be in the infrared, visible or ultraviolet. On Earth – which has a magnetic field created by a dynamo inside of the planet – the light is visible. Saturn’s recently discovered aurorae can emit light in the infrared, and Jupiter’s aurorae are much more complicated, emitting light in the UV.

Mars doesn’t have it’s own magnetic field, though. Large stores of magnetic rocks in the crust of Mars are scattered throughout the entire planet, and the aurorae correlate with the concentrations of these rock.

NASA
A map of Mars' many magnetic fields - they're all over the place! Image Credit: NASA

SPICAM has observed nine aurorae, all near highly magnetic locations mapped by the Mars Global Surveyor Electron Reflectometer. Though there is a strong correlation between the aurorae and magnetic locations, this isn’t absolute proof that the magnetic fields in these regions are the only cause of the aurorae, but it is rather likely.

The large magnetic field structure of the Earth accelerates the charged particles, which slam into the atmosphere and spark auroral events. The dispersed nature of the magnetic fields on Mars wouldn’t do this, which leaves scientists unsure as to how exactly the aurorae are created.
“It may be that magnetic fields on Mars connect with the solar wind, providing a road for the electrons to travel along,” said Francois Leblanc, from the Service d’Aéronomie, lead author of a paper on the aurorae observed so far, titled “Observations of aurorae by SPICAM ultraviolet spectrograph on board Mars Express: Simultaneous ASPERA-3 and MARSIS measurements” which appeared in the August 2008 Journal of Geophysical research.

The elements that create the colors we see here on Earth – molecular and atomic oxygen and molecular nitrogen – are not very abundant in the thin atmosphere of Mars. SPICAM can only see in the ultraviolet, so is not equipped to detect whether the aurorae would be visible to the human eye. So will future Martian colonists looking out of their glass-domed cities have spectacular light shows every time the Sun acts up?

“We’re not sure whether the aurorae will be bright enough to be observed at visible wavelengths,” said Leblanc.

Source: ESA

“Wasteful” Sample Storage Box Removed from Mars Science Laboratory

The MSL - a monster amongst rovers (hopefully) (NASA)

Stern: “The Mars program is slowly committing suicide in front of our very eyes”
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NASA’s Mars Science Laboratory (MSL) has been beset by technical challenges and inevitable budget overruns. The nuclear-powered rover is set for an October 2009 launch and engineers are doubling their efforts to ensure the MSL makes it to the launchpad on time. In an attempt to save money and (hopefully) time, MSL program managers have decided to remove a $2 million component from the car-sized wheeled robot. A sample storage box was conceived long after the initial MSL science goals were drawn up (a pretty controversial decision in itself), so analysed rock samples could be saved for a possible future Mars sample-return mission.

Now NASA has deemed the box “of low science value” and “wasteful” on resources that could be directed elsewhere, but outspoken critics have pointed out that by removing the box is just another component on the road to the demise of NASA’s Mars exploration program…

Wouldn’t it be great if we could dig up samples of Martian rock and launch it back to Earth? Just think about the in-depth science that could be carried out on a sample removed directly from the Mars surface. Although rovers and landers are great for in-situ experiments, you still cannot beat analysis by a scientist. Assuming infinite resources, a Mars sample return mission would be technologically possible, but in the current climate of budget cuts and overspending, it is virtually impossible. The money, quite simply, is better spent elsewhere.

So, there’s NASA constructing the most advanced rover to be sent to Mars, ever. It will be a long-term mission, powered not by sunlight but by long-lasting radioisotope thermal generators (RTGs). It will do amazing science whilst dominating the Martian landscape by day and by night. After the MSL design was drawn up, a new piece of equipment was dreamt up: a sample storage box. This may not sound very exciting, after all, its only purpose is to store rocks. Why? So a future mission can retrieve the samples and return them to Earth.

Last week, it was decided that the storage box was surplus to requirements and it will be removed from the MSL. Although it had already been built, MSL project scientist John Grotzinger (Caltech) pointed out that the instrument would have taken time away from the other instruments.

The cache would have tied our hands to some extent,” Grotzinger said. “Now it restores our freedom.”

The MSL has run up a pricetag of over $1.5 billion, and it is expected to balloon to $2 billion by the time it launches to the Red Planet, so any excess cost should be trimmed where necessary. Alas, the storage box is low on the list of priorities and was dropped, even though $2 million had already been wasted in its development. NASA’s rationale is that more time and money will need to be put into the cache, so they may as well cut their losses.

This move isn’t a popular decision however. Ex-NASA space sciences chief Alan Stern (who resigned in March after the controversy surrounding the erroneous announcement that funds to the existing Mars rovers would be cut), is very critical of the move. “The Mars program is slowly committing suicide in front of our very eyes,” said Stern. “The only concrete step toward a sample return has been tossed after it has already been built. How does that save money?

Indeed, this may be a signal that a sample return mission is not on the cards, certainly not involving the MSL. I would question why the sample storage box was included in the MSL at all, surely any future sample return attempt would be carried out by a devoted sample return mission? What was the motivation behind picking up rocks the MSL had analysed, only to store them for many years until a theoretical sample return robot collects the box?

When the cache was originally announced, scientists pointed out that the samples will have probably degraded by the time they are sent back anyway, so what’s the point?

Either way, the box now frees up some space on the MSL for an instrumentation cleaning station, but I can’t help but think the $2 million waste could have been prevented…

Original source: Herald Tribune

Mars Atmospheric “Bubbles” Carried Away by the Solar Wind

Why do planets like Mars have a different atmosphere than Earth? Credit: NASA

[/caption]Mars is a strange planet.

There is evidence that the Red Planet once played host to a thick atmosphere and vast oceans. However, at some point in its evolution, the planet seemed to leak the majority of its atmospheric gases into space, and its oceans evaporated (or froze and then sublimated, depending on how fast atmospheric pressure was lost). There are several theories as to how the Martian atmosphere wasted away to 1% of that of the Earth’s, including the slow erosion by solar wind particles and a sudden, catastrophic asteroid impact, blasting the atmosphere into space.

Planetary scientists have known for a long time that the Martian magnetic field is very weak and therefore has little protective strength from the continuous solar wind. Through analysis of data from the retired NASA Mars Global Surveyor (MGS) satellite, a new insight has been gained.

Far from being benign however, this weak crustal magnetic field may actually be having an adverse effect on the atmosphere, capturing atmospheric particles in magnetic “bubbles” (a.k.a. plasmoids) over a thousand kilometres wide, before being blown en-mass into space…

The erosion of the Martian atmosphere by the solar wind has been long suspected as the primary mechanism behind the loss of Martian air. Although Mars air is significantly different to our own (the Martian atmosphere is primarily CO2-based, whereas the terrestrial atmosphere has a breathable nitrogen-oxygen mix), it was once thought to be much more dense than it is today.

So where did the atmosphere go? As the Martian magnetosphere is pretty insignificant (scientist believe that the global magnetic field may have been a lot stronger in the past and possibly damaged by an asteroid impact), there is little to deflect energetic solar wind ions from interacting with the atmosphere below. On Earth, we have a very strong magnetosphere acting as an invisible forcefield, preventing charged particles from entering our atmosphere. Mars does not have this luxury.

During the Mars Global Surveyor mission, launched in 1996 (ending in 2006), the satellite detected a very patchy magnetic field originating from the Martian crust, predominately in the southern hemisphere. The natural thought would be that, although weak, this patchy field might provide some limited protection for the atmosphere. According to new research using old MGS data, this is probably not the case; the crustal magnetic field may be contributing to, possibly accelerating, the air loss.

Dave Brain of UC Berkeley presented this slide at the 2008 Huntsville Plasma Workshop to explain in cartoon fashion how plasmoids carry air away from Mars.
Dave Brain of UC Berkeley presented this slide at the 2008 Huntsville Plasma Workshop to explain in cartoon fashion how plasmoids carry air away from Mars.
As the patchy crustal magnetic field wells up from the Martian surface, it creates “umbrellas” of magnetic flux, trapping charged atmospheric particles. Dozens of magnetic umbrellas cover up to 40% of Mars (primarily concentrated in the south), reaching above the atmosphere. These magnetic structures are therefore open to attack from the solar wind.

The umbrellas are where coherent chunks of air are torn away,” said David Brain of UC Berkeley, who presented his MGS research at the 2008 Huntsville Plasma Workshop on October 27th.

Although this might sound dramatic, there is a real possibility that this process has been observed on Mars for the first time. The magnetic umbrellas reach through the atmosphere and feel dynamic pressure from the solar wind. What happens next is a well known mechanism in the field of magnetohydrodynamics (MHD): reconnection.

As the crustal umbrellas make contact with the interplanetary magnetic field (IMF) carried by the solar wind, there is a chance reconnection may occur. According to David Brain, the MGS passed through such a reconnection region during one of its orbits. “The joined fields wrapped themselves around a packet of gas at the top of the Martian atmosphere, forming a magnetic capsule a thousand kilometers wide with ionized air trapped inside,” he said. “Solar wind pressure caused the capsule to ‘pinch off’ and it blew away, taking its cargo of air with it.”

Since this first result, Brain has found a further dozen magnetic “bubbles” carrying chunks of the Martian ionosphere with them. These bubbles are known as “plasmoids” as they contain charged particles, or plasma.

Brain is keen to point out that these results are far from conclusive. For example, the MGS was only equipped to detect one charged particle, the electron; ions have different characteristics and may therefore be affected differently. Also, the satellite took measurements at a constant altitude at the same local time of day. More data during different times and different altitudes are required.

One such NASA mission that might be able to assist in the plasmoid hunt is the Mars Atmosphere and Volatile Evolution satellite (MAVEN), scheduled for launch in 2013. MAVEN will analyse the Martian atmosphere to specifically study erosion by the solar wind, detecting electrons and ions; measuring not only the magnetic, but the electric field too. MAVEN’s elliptical orbit will also allow the probe to investigate various altitudes at different times.

So we await MAVEN to prove or disprove Brain’s plasmoid theory. Either way, this is some tantalizing evidence pointing to a rather unexpected mechanism that could be, quite literally, ripping Mars’ atmosphere into space…

Source: NASA

Despite Dust Storms, Solar Power is Best for Mars Colonies

Spot the difference: Spirits solar panels collected a lot of dust in two years (NASA/JPL)

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Dust — a solar panel’s worst nightmare.

Is sending solar-powered robots to the Red Planet a bad idea? Mars is a very dusty planet, and Mars dust sticks to everything, especially solar arrays. After all, Phoenix’s death was probably hastened by a Sun-blocking dust storm, and rover Spirit was battered by the combined solar panel-coated dust layer plus dust storm, nearly draining its batteries (as can be seen in the comparison above, after two years on the Martian surface, Spirit’s dusty layer was already an acute problem).

However, a NASA-sponsored MIT think-tank has weighed up the future energy needs of a manned settlement on Mars and arrived at an interesting conclusion…

It sounds like the “nuclear space debate” continues. Thinking back to when Galileo was launched toward Jupiter in 1989, or when Cassini was sent to Saturn in 1997, huge protests erupted from critics, Cape Canaveral neighbours and anti-nuclear organizations. The argument was that should there be a launch accident, the radioactive material contained inside the radioisotope thermal generators (RTGs) could be scattered through the atmosphere and over a wide area on the ground (i.e. death and destruction). While this is a scary thought, NASA engineers were very quick to point out that RTGs are virtually indestructible, even under extreme conditions during an explosion and atmospheric re-entry.

The motivation for sending plutonium (non-weapon grade Pu238) on board missions to Jupiter and Saturn has even been called into question, spawning wild conspiracy theories such as “Project Lucifer.” Therefore, it seems only sensible that NASA should want to carry out an in-depth study of all energy production techniques before committing to a potentially unpopular (and therefore politically damaging) nuclear source for future Mars colonies.

With the help of energy specialists from the Massachusetts Institute of Technology (MIT), NASA commissioned a study of how future manned Mars settlements can be powered. Will nuclear generators need to be constructed? Or can solar panels fulfil our proto-colony’s energy needs (regardless of the dust situation)?

Interestingly, if positioned in the correct location, solar arrays might function just as well, if not better, than the nuclear options. Solar panels could provide all the energy a fledgling colony needs.

The MIT researchers assessed 13 different energy generation systems and compared solar and nuclear options. In a presentation last month at the International Astronautical Congress in Glasgow, MIT engineer Wilfried Hofstetter compared nuclear fission reactors, RTGs, Sun-tracking solar panel arrays and non-tracking thin-film solar arrays laid atop the Martian landscape.

Like any space travel endeavour, efficiency is paramount; astronauts will need to utilize every last energy-generating ounce of equipment sent to Mars (including back-up systems).

It would appear that a large solar panel array can match nuclear generators, only if they are situated at a latitude of 0-40° north of the Martian equator. Southern latitudes have much less solar energy available for most of the year.

So what’s the best plan of action? According to Hofstetter, a Mars mission should be able to transport several 2 metre-wide rolls of thin-film solar panel arrays. Rolling out an array of these thin-film rolls could supply ample energy to a colony. For example, if the array is positioned at 25° north, measuring 100×100 metres, 100 kilowatts can be generated. The MIT researchers even calculated it would take two astronauts 17 hours to construct the array (alternatively they could get a robot to do it).

Commenting on this Mars energy solution, Colin Pillinger, planetary scientist with the Open University, UK (and head Beagle 2 scientist) said the solar array’s old foe — dust — shouldn’t be too much of a problem after all. “Dust storms tend to start in well-known places in the southern hemisphere as it warms up, so it shouldn’t be too difficult to avoid them,” he said.

So the skies may be clear for solar energy on Mars after all. Even though dust storms causes problems for our robotic explorers, manned expeditions may be able to avoid them all together. Besides, I don’t see why astronauts couldn’t pack some brushes to wipe down the arrays should dust become a problem…

Source: New Scientist

MSL News: Landing Sites and Naming Contest

Landing sites for the Mars Science Laboratory have been narrowed down to four intriguing places on the Red Planet. The car-sized rover will have the capability to travel to more scientifically compelling sites, and with its radioisotope power source, it won’t need to rely on solar power, allowing for more flexibility in locations say project leaders at the Jet Propulsion Laboratory. After seeking input from international experts on Mars and engineers working on the landing systems, here are the four sites JPL announced (drumroll)…

Oh, before listing the sites, NASA is having a name the rover contest for MSL, so check that out, too!

Eberswalde: where an ancient river deposited a delta in a possible lake, south of Mars equator.

Gale: a crater with a mountain within that has stacked layers including clays and sulfates, near the equator. This was a favorite site for the Mars Exploration Rovers, but it was deemed to hazardous for them. Not so for MSL.

Holden: a crater containing alluvial fans, flood deposits, possible lake beds and clay-rich deposits, in the southern hemisphere.

Mawrth: , which shows exposed layers containing at least two types of clay, in the northern hemisphere, near the edge of a vast Martian highland.

“All four of these sites would be great places to use our roving laboratory to study the processes and history of early Martian environments and whether any of these environments were capable of supporting microbial life and its preservation as biosignatures,” said John Grotzinger of the California Institute of Technology, Pasadena. He is the project scientist for the Mars Science Laboratory.

Wheels were put on MSL in August 2008. Image Credit: NASA/JPL-Caltech
Wheels were put on MSL in August 2008. Image Credit: NASA/JPL-Caltech

During the past two years, multiple observations of dozens of candidate sites by NASA’s Mars Reconnaissance Orbiter have augmented data from earlier orbiters for evaluating sites’ scientific attractions and engineering risks.

JPL is assembling and testing the Mars Science Laboratory spacecraft for launch in fall 2009.

“Landing on Mars always is a risky balance between science and engineering. The safest sites are flat, but the spectacular geology is generally where there are ups and downs, such as hills and canyons. That’s why we have engineered this spacecraft to make more sites qualify as safe,” said JPL’s Michael Watkins, mission manager for the Mars Science Laboratory. “This will be the first spacecraft that can adjust its course as it descends through the Martian atmosphere, responding to variability in the atmosphere. This ability to land in much smaller areas than previous missions, plus capabilities to land at higher elevations and drive farther, allows us consider more places the scientists want to explore.”

MSL is designed to hit a target area roughly 20 kilometers (12 miles) in diameter. Also, a new “skycrane” technology to lower the rover on a tether for the final touchdown can accommodate more slope than the airbag method used for Spirit and Opportunity.

Source: JPL

MRO Finds Huge Underground Glaciers on Mars

Possible underground glaciers on Mars. Credit: NASA

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There’s more than just a little ice under Mars’ surface. According to data from the Mars Reconnaissance Orbiter radar system, vast Martian glaciers of water ice lie buried under rocky debris. And this ice is not just at the Arctic region where the Phoenix lander scratched the surface in searching for ice. MRO found evidence for a huge amount of underground ice at much lower latitudes than any ice previously identified on the Red Planet. “Altogether, these glaciers almost certainly represent the largest reservoir of water ice on Mars that is not in the polar caps,” said John W. Holt of the University of Texas at Austin, who is lead author of the report. “Just one of the features we examined is three times larger than the city of Los Angeles and up to half a mile thick. And there are many more. In addition to their scientific value, they could be a source of water to support future exploration of Mars.”


Scientists say buried glaciers extend for dozens of miles from the edges of mountains or cliffs. A layer of rocky debris blanketing the ice may have preserved the underground glaciers as remnants from an ice sheet that covered middle latitudes during a past ice age. This discovery is similar to massive ice glaciers that have been detected under rocky coverings in Antarctica.

Scientists have been puzzled by what are known as aprons — gently sloping areas containing rocky deposits at the bases of taller geographical features — since NASA’s Viking orbiters first observed them on the Martian surface in the1970s. One theory has been that the aprons are flows of rocky debris lubricated by a small amount ice. Now, the shallow radar instrument on the Mars Reconnaissance Orbiter has provided scientists an answer to this Martian puzzle.

“These results are the smoking gun pointing to the presence of large amounts of water ice at these latitudes,” said Ali Safaeinili, a shallow radar instruments team member with NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

The buried glaciers lie in the Hellas Basin region of Mars’ southern hemisphere. The radar also has detected similar-appearing aprons extending from cliffs in the northern hemisphere.

Artists concept of a glacier on Mars.  Credit: NASA
Artists concept of a glacier on Mars. Credit: NASA

Radar echoes received by the spacecraft indicated radio waves pass through the aprons and reflect off a deeper surface below without significant loss in strength. That is expected if the apron areas are composed of thick ice under a relatively thin covering. The radar does not detect reflections from the interior of these deposits as would occur if they contained significant rock debris. The apparent velocity of radio waves passing through the apron is consistent with a composition of water ice.

“There’s an even larger volume of water ice in the northern deposits,” said JPL geologist Jeffrey J. Plaut, who will be publishing results about these deposits in the American Geophysical Union’s Geophysical Research Letters. “The fact these features are in the same latitude bands, about 35 to 60 degrees in both hemispheres, points to a climate-driven mechanism for explaining how they got there.”

The rocky debris blanket topping the glaciers apparently has protected the ice from vaporizing, which would happen if it were exposed to the atmosphere at these latitudes.

“A key question is, how did the ice get there in the first place?” said James W. Head of Brown University in Providence, R.I. “The tilt of Mars’ spin axis sometimes gets much greater than it is now. Climate modeling tells us ice sheets could cover mid-latitude regions of Mars during those high-tilt periods. The buried glaciers make sense as preserved fragments from an ice age millions of years ago. On Earth, such buried glacial ice in Antarctica preserves the record of traces of ancient organisms and past climate history.”

Source: NASA

Evidence For Vast Oceans On Ancient Mars

This 3D map superimposes gamma-ray data from Mars Odyssey's Gamma-Ray Spectrometer onto topographic data from the laser altimeter onboard the Mars Global Surveyor.

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Data from the Mars Odyssey orbiter’s Gamma Ray Spectrometer provides new evidence for the controversial idea that oceans once covered about a third of ancient Mars. Spacecraft images going back to Mariner 9 in the early 1970s and the Viking orbiters and landers later in the 1970s up to the current orbiters and rovers have showed widespread evidence for a watery past for Mars. About 20 years ago, several studies sparked a scientific debate on the possible existence of ancient Martian oceans marked by visible shorelines. Images and topographic maps provide evidence for two different oceans in one area, perhaps occuring at different times in Mars history, a larger one at an earlier time, and a smaller once existing later. Odyssey’s GRS can detect subsurface elements, and new data confirms the right combination of elements for two ancient shorelines.

The spectrometer has the unique ability to detect elements buried as much as 1/3 meter, or 13 inches, below the surface by the gamma rays they emit. That capability led to GRS’ 2002 discovery of water-ice near the surface near Mars arctic region, leading to the decision for the Phoenix landing site.

“Our investigation posed the question, ‘Might we see a greater concentration of these elements within the ancient shorelines because water and rock containing the elements moved from the highlands to the lowlands, where they eventually ponded as large water bodies?'” said University of Arizona planetary geologist James M. Dohm, who led the international investigation. “We compared Gamma Ray Spectrometer data on potassium, thorium and iron above and below a shoreline believed to mark an ancient ocean that covered a third of Mars’ surface, and an inner shoreline believed to mark a younger, smaller ocean.”

Results suggest that past watery conditions likely leached, transported and concentrated such elements as potassium, thorium and iron, Dohm said. “The regions below and above the two shoreline boundaries are like cookie cutouts that can be compared to the regions above the boundaries, as well as the total region.”

The younger, inner shoreline is evidence that an ocean about 10 times the size of the Mediterranean Sea, or about the size of North America, existed on the northern plains of Mars a few billion years ago. The larger, more ancient shoreline that covered a third of Mars held an ocean about 20 times the size of the Mediterranean, the researchers estimate.

The potassium-thorium-iron enriched areas occur below the older and younger paleo-ocean boundaries with respect to the entire region, they said. The scientists used data from Mars Global Surveyor’s laser altimeter for topographic maps of the regions in their study.

Scientists studying spacecraft images have a hard time confirming “shoreline” landforms, the researchers said, because Mars shorelines would look different from Earth’s shorelines. Earth’s coastal shorelines are largely a direct result of powerful tides caused by gravitational interaction between Earth and the moon, but Mars lacks a sizable moon. Another difference is that lakes or seas on Mars could have formed largely from giant debris flows and liquefied sediments. Still another difference is that Mars oceans may have been ice-covered, which would prevent wave action.

“The GRS adds key information to the long-standing oceans-on-Mars controversy,” Dohm said. “But the debate is likely to continue well into the future, perhaps even when scientists can finally walk the Martian surface with instruments in hand, with a network of smarter spaceborne, airborne and ground-based robotic systems in their midst.”

Source: U of Arizona

Mars Rover Spirit Surviving on a Low Energy Diet

Spirit overlooking Gusev Crater (NASA artist impression)

[/caption]Last week, Mars Exploration Rover Spirit looked as if its sols were numbered. Hot on the heals of the demise of the frozen Phoenix lander, Spirit was about to succumb to a low-energy death brought on by a dust storm. The build-up of dust on the rover’s solar panels were already causing a serious problem, but as a storm raged over Gusev Crater, power output from the panels slumped to an all-time low. As Nancy reported on November 11th, mission controllers were forced to switch Spirit into a low-energy state, leaving them with no other choice but to command the robot to be silent. Although tensions were high, Spirit broke the silence last Thursday.

Now NASA controllers are working hard to manage Spirit’s power production, hopefully extending the life of the highly successful rover longer still…

At its worst, Spirit’s solar panels were outputting 89 watt hours of energy just before NASA mission control took decisive action by shutting down non-essential heaters on the rover. Before the storm, Spirit was already covered in a thick layer of dust from nearly five years of Mars roving, allowing only 33% of the sunlight falling on the panels to be used by the photovoltaic cells. During the storm, the dust situation had worsened, valuable sunlight was getting blocked by atmospheric dust clouds. Spirit was in trouble.

NASA/JPL-Caltech/Cornell
Spirit's solar panels were already very dusty a year ago (NASA)
At their peak, both Spirit and Opportunity were able to generate 700 watt hours of energy. Should their power output drop to 150 watt hours, batteries start to drain while running heaters to keep essential equipment and instrumentation warmed. Spirit’s 89 watt hours was therefore a dire situation. Fortunately after the intrepid rover rode out the storm and checked in with mission control, by the end of Thursday, NASA was pleased to see Spirit’s solar panels generating 161 watt hours of energy. After four days, the skies were clearing and Spirit could begin slowly recharging its batteries. However, the layer of dust on top of the solar panels had thickened, allowing 3% less light to get through.

Spirit is not out of the woods yet,” said Mars Exploration Rover (MER) Project Manager John Callas at NASA’s Jet Propulsion Laboratory. “The storm and all its dust have not gone away completely. And this is the time of the Martian year when storms like this can occur. So the plan ahead is to stay cautious with the rover and work on recharging the batteries while waiting out the rest of the storm’s activity.”

So, Spirit has been put on a low energy consumption diet. On Friday commands were sent to the rover to keep some of its heaters switched off and to conduct limited observations and communications. Spirit will be on a “go-slow” until the end of the month to give it some time to recover, recharge and be prepared in the event of a follow-up Gusev Crater storm.

At the end of the month no commands will be sent from Earth for a period of two weeks, as the Sun will be blocking the line of sight with Mars. Therefore Spirit will have lots of time to recover from the dust storm ordeal until communications between Earth and Mars return. After this period, NASA plans to move Spirit from its current location inside Gusev Crater (a low platform called “Home Plate”) so it can continue to explore the Red Planet (assuming there are no more damaging storms ahead).

Although this is all a huge relief, I can’t help but think that Spirit is on borrowed time.

Source: NASA

Mars Rover Contact Reestablished, Spirit is Alive!

Relieved. MER Spirit (NASA)

[/caption]Just when we were growing concerned that we might be losing two Mars surface missions within a week of each other, it turns out Mars Exploration Rover Spirit has survived its recent run-in with a Sun-dimming dust storm. On Tuesday, Nancy reported that Spirit had generated a record low power output from its solar panels, indicating the storm could drive Spirit’s energy levels to a point where an emergency fail-safe would switch the wheeled robot into a sunlight-deprived coma. Mission controllers sent Spirit commands to shut down non-essential instrumentation and instructed it not to communicate with NASA until today.

It would appear the rugged rover weathered the storm, expertly avoided a low-power fault and after four days of silence, sent the signal to NASA just as it was told to do. What an incredible little robot

One might think that using solar panels to collect light on a planet where Sun-blocking dust is a problem is a bit silly. After all, it seems the Phoenix Mars lander succumbed to an arctic dust storm-induced drained battery, and Spirit was also hit by the solar panel’s old foe, a dust storm in Gusev Crater. But the key point that needs to be remembered in both cases is that these missions operated far beyond their expected lifespan. Phoenix was only supposed to be digging into the Martian dirt for three months (it lasted five months), plus the lander had a pretty tough deadline to keep to: the loss of sunlight and the freezing cold of the onset of the northern winter. Phoenix knew its fate, but it was able to push into the dark and cold for a little longer…

However, Spirit’s fate was far from sealed. Usually the rover enjoys a full sol of daylight, day and night as regular as clockwork. This is another piece of NASA engineering that has surpassed every expectation there is. I doubt that any scientist would have said that a mission designed to operate for only three months, would be roving the Martian surface nearly five years later! So already, every minute Spirit (and its twin rover Opportunity on the other side of the planet) spends transmitting data from the Red Planet is a huge bonus.

However, MER scientists were not going to let Spirit drop dead due to a flat battery. When NASA realised Spirit was beginning to suffer, drawing much less power than was needed from its solar panels, action was taken. Firstly, some heaters were switched off (one heater protects the thermal emission spectrometer instrument from the cold), and Spirit was put on a strict low-energy consumption routine. This routine meant commanding Spirit not to attempt to communicate with Earth for four days, which was probably the most nerve-racking measure that could be taken; once communication is severed, who’s to say we’d ever hear from the rover again?

Even though engineers had stopped Spirit from communicating, they continued to listen, just in case Spirit dropped into a low-energy shutdown mode. However, no signal was received until today (Thursday), right when Spirit was scheduled to phone home. At mission control at JPL in Pasadena, CA, NASA engineers shouted “she’s talking,” when they got word that Spirit had made contact.

Although her batteries are low, the rover is still working and talking with NASA. Let’s hope Spirit holds on for a while longer…

Source: AP

Spirit Rover in Trouble

The deck of NASA's Mars Exploration Rover Spirit is so dusty that the rover almost blends into the dusty background. Image credit: NASA/JPL-Caltech/Cornell

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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