Tag Archives: Mars Reconnaissance Orbiter

20 Years at Mars!

One more post today, because this is an important one. ¬†ūüėČ ¬†Yesterday was Independence Day here in America, and for space geeks, it was important for another reason — it was the twentieth anniversary of the Pathfinder landing on Mars, and marked twenty years of continuous exploration of the Red Planet.

It’s amazing to think about. ¬†I remember exactly where I was on July 4, 1997. ¬†I was at an Independence Day party at my uncle’s house, and he had a TV on for the nerdier among us to watch and see when Pathfinder landed. ¬†It was very exciting. ¬†Pathfinder was the first lander to operate on Mars since November of 1982, when Viking 1 lost contact with Earth, a very long gap.

Mars had developed a powerful reputation as the Bermuda Triangle of the Solar System.  Before Viking, there had been 21 attempted missions to Mars, but only six had been successful.  After Viking, there were no further attempts until 1988, when the Soviet Union sent the ill-fated Phobos missions, both of which failed.  In 1992, NASA made another attempt with Mars Observer, which is believed to have exploded just before orbital insertion due to a fault in its propulsion system.  It seemed like Mars was off limits.  The next Mars transfer window came and went.

In 1996, another Mars window opened, and this time both NASA and the Russian Federation’s Rosaviacosmos were prepared to send spacecraft. ¬†It would be one of the last ambitious deep space efforts by Roscosmos for some time. ¬†Rosaviacosmos sent Mars 96, a highly ambitious spacecraft built collaboratively with European nations and carrying an orbiter, landers, and ground penetrators. ¬†It failed to leave Earth orbit, and eventually reentered Earth’s atmosphere. ¬†(The same fate would later befall Fobos-Grunt.) ¬† ¬†NASA sent Mars Pathfinder, its hitchhiking Sojourner rover, and Mars Global Surveyor.

On July 4, 1997, Mars Pathfinder landed on Mars with an innovative tetrahedral lander studded with airbags, which allowed it to hit the surface in any configuration and still end up upright at the end.  Although Pathfinder had a brief scare due to an undetected race condition in its computer software, it was recovered and went on to a very full mission, deploying the breadbox-sized Sojourner rover to become the first wheels on Mars.  Pathfinder continued operating until October 7, 1997, beating its design specs by about two and a half months.

But before it failed, another spacecraft arrived: Mars Global Surveyor, the first fully successful Mars orbiter since the Viking Orbiters in the 1970s.  Mars Global Surveyor set a record (since beaten) for total operating time at Mars, lasting nearly a decade (well past its one-year primary mission), going on to conduct joint observations with later spacecraft and serving as the first Mars communications relay station, transmitting data from landers back to Earth.

After Pathfinder and MGS arrived, many more followed, although Mars continued to earn its reputation as the Eater of Space Probes. ¬†The 1998 launch window was fraught with failures, from the Japanese Nozomi probe (ran out of propellant prematurely due to a fault), to NASA’s Mars Climate Observer (killed by an unknown unit conversion error resulting in deorbit rather than orbit capture), to Mars Polar Lander (lost due to premature shutdown of the landing engine) and its piggybacked Deep Space 2 penetrator (MPL crashed before it could be deployed). ¬†But the 2001 window showed a reversal of fortunes. ¬†MGS, the lone operational spacecraft at Mars, would be joined by NASA’s Mars Odyssey 2001, which remains in operation today. ¬†In 2003, MGS and Odyssey would be joined by ESA’s Mars Express, which continues to operate today, although Mars Express’s piggybacked Beagle 2 lander (provided by the United Kingdom) never called home. ¬†Orbital photography eventually revealed that it had landed in a very unfortunate posture among a boulder field, and was likely unable to open itself properly — this is a risk for any robotic lander, and one that is nearly impossible to prevent. ¬† ¬†But also in 2003 launched two of the most phenomenal overachievers in the history of Mars exploration: NASA’s Mars Exploration Rovers, Spirit and Opportunity. ¬†Both operated far past their original three-month mission. ¬†Spirit was eventually killed when it became mired in a posture which did not give its solar powers enough light during the long Martian winter, but Opportunity remains in operation today, having set both endurance and mileage records.

The 2005 launch window saw the most powerful camera ever sent to Mars, aboard Mars Reconnaissance Orbiter. ¬†This spacecraft has enabled exquisitely detailed imagery over time, tracking changes in the surface features of the Red Planet beyond the capabilities of its predecessors, and even photographing many of the landers and rovers. MRO remains in operation today. ¬†In 2007, Mars Phoenix Lander was sent, partially reflying some of the experiments planned for Mars Polar Lander, as well as following new plans, adhering to the overall NASA strategy of “follow the water”. ¬†Phoenix operated for 157 sols (Martian days), nearly double the planned mission duration, when the polar darkness of winter arrived and claimed it. ¬†Among its many discoveries was the first observation of liquid water on the surface of Mars, likely water melted from the icepack by its landing rockets and then briefly recondensed on the spacecraft’s landing legs before boiling away in the low atmospheric pressure.

The 2011 window saw both tragedy and triumph — first, the loss of Roscosmos’ Fobos-Grunt and its piggybacked Yinghu0-1 lander from China, and then the brilliant success of Mars Science Laboratory “Curiosity”. ¬†Curiosity is by far the largest rover ever sent to another world, so large that the tetrahedral airbag lander of Mars Pathfinder and the twin Mars Exploration Rovers would not suffice. ¬†Instead, a “Skycrane” vehicle was devised to bring it in like a helicopter. ¬†The system worked perfectly, and Curiosity remains in operation today, although the perils of exploring the unknown have been driven home by the shocking amount of damage in its aluminum wheels; the rocks of Gale Crater seem to be much harder and sharper than those encountered anywhere else that landers have visited.

In 2013, NASA’s MAVEN was launched; it is still operating in Mars orbit today. ¬†And another nation joined the elite club of deep space explorers, as India’s ISRO placed the Mangalyaan (Mars Orbiter Mission) spacecraft into Mars orbit. ¬†It, too, remains in operation today. ¬†2016, the latest Mars window, saw the launch of ExoMars, a collaboration between ESA and Russia, and its piggybacked Schiaparelli lander. ¬†ExoMars remains in operation today, while Schiaparelli unfortunately was lost on landing.

So, that makes 20 continuous years of spacecraft operating on Mars or in orbit around it, and today there are six functioning orbiters and two functioning rovers on the surface.  It makes a wonderful change from the long drought of Mars exploration before that!  It is quite likely that there will never again be a gap in Mars exploration, not now that there are so many different space agencies at work on it.

The next window opens in May. ¬†NASA plans to launch its InSight spacecraft (delayed from the 2016 window).¬†In 2020, things get really busy. NASA has another mission in the planning stages, and Europe and Russia will be collaborating on the second ExoMars spacecraft. ¬†China and Japan both are planning to make their second attempts for Mars, and the United Arab Emirates is planning their first deep space mission, and India might manage their second Mangalyaan in that window (if not, they’ll likely make the following window). ¬†And perhaps most intriguingly of all, in 2020 SpaceX is planning their Red Dragon mission, the first crewed mission to Mars (unless someone manages to beat them to it). ¬†We’ll have to wait and see if they can actually make that date; it seems a tad ambitious to me! ¬†But wouldn’t it be exciting?

 

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MRO has found Schiaparelli

Unfortunately, it confirms what we all pretty much already knew: it has crashed.  Any faint hope that the apparent three-second burn was due to communications problems has been dashed.  MRO photographed the lander (and its parachute) in this image.  The animation basically compares an image of the same location taken before the landing with now:

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This image is from a preplanned sequence of images designed specifically to find the lander after touchdown; MRO has photographed several landers in this manner, including Mars Phoenix Lander and Mars Science Laboratory Curiosity, and it can provide invaluable engineering data.  On this occasion, that paid off in spades by providing the first post-landing data on what happened to the probe.

The white dot that appears in the bottom of the right-hand inset is probably the supersonic parachute. ¬†The dark smudge at the top is probably the impact site of Schiaparelli. ¬†This spot is 5.4 km¬†uprange from the target site for the landing, although well within Schiaparelli’s landing ellipse and thus a reasonable place to have found the probe even if all had gone well – and if nothing else, this indicates it was right on track before the mishap occurred. ¬† ¬†The bright and dark patches are about a kilometer apart; the dark patch is about 15 x 40 meters, which is far too large to represent an intact lander. ¬†If, as seems likely, the engines shut off after just a few seconds, it would have had full tanks of hydrazine monopropellant; it could have exploded on impact. ¬†Analyzing the descent data and the imagery, ESA engineers believe it may have fallen 2-4 km, resulting in an impact velocity of upwards of 300 km per hour, which would have been pretty destructive even if the tanks didn’t rupture.

It’s unfortunate, but ESA is keeping a positive attitude. ¬†The primary objective for this mission was the Trace Gas Orbiter, and that is doing excellently. ¬†TGO is a necessary element for phase two of the ExoMars mission, a rover due to launch in 2020 (originally 2018, but¬†about six months ago, ESA moved it to the next Mars window due to technical delays), so it is good to have it there. ¬†And while Schiaparelli will not have been able to test all of the landing technology, it did successfully validate most of it. ¬†Going to Mars is extremely difficult, and Schiaparelli is far from the first probe to be eaten by the Red Planet. ¬†ESA will learn from this, and incorporate lessons from it into the ExoMars rover’s landing system.

Meanwhile, a higher-resolution imaging sequence of the site by MRO is being planned, to hopefully collect more specific information on the ill-fated spacecraft.

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The strange snow on other worlds

It’s winter here in Minnesota, and that means snowsports! ¬†Sure, it’s unusually warm this January, and our snow is in danger of melting, but we still love it. ¬†Fluffy flakes of frozen water, piled up and perfect for skiing, sledding, snowmobiling, and more!

But snow isn’t just a feature of Earth. ¬†Enceladus is believed to have deep powder, fallen as snow from its huge geysers. ¬†And other worlds have stranger snows….

MARS

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Mars is famously thought of as a desert, but anybody with a large enough telescope can tell that it has seasonal icecaps at its poles. ¬†But¬†it’s not just the kind of ice we know. ¬†The water ice at the poles is pretty much permanent, but the part that grows and recedes isn’t water. ¬†It’s carbon dioxide. ¬†For a long time, it’s been believed it grows as frost, but Mars Reconnaissance Orbiter¬†discovered evidence that it doesn’t just precipitate out on the ground; it comes out in the atmosphere and falls as snow. ¬†Dry ice snow! ¬†It’s white, but¬†in other respects very different from what we’re used to. ¬†Experiments on Earth suggest the “flakes” will actually be tiny cubes little larger than a grain of sand, so it might be more like skiing on a big mound of salt, except that dry ice melts at a low enough temperature that the friction of your skis could melt it — if it weren’t for the high pressure required to liquify CO2. ¬†It would go straight from solid to gas, and you could completely lose control. ¬†In fact, actual observations of the polar regions suggests that it regularly does sublimate, with explosive results, as it heats up in the spring. ¬†So maybe not the best place to ski.

Planetary Society: Dry Ice Snowfall at the Poles of Mars

IO

 

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Io is the innermost of Jupiter’s four largest moons, the Galilean satellites. ¬†The twin Voyager spacecraft quickly revealed that it was like no other moon, and is actually more volcanically active than the Earth is. ¬†Much more: we now know that like Europa, it has a vast subsurface ocean, but unlike Europa it’s not water. ¬†It’s molten rock, and mostly sulfur. ¬†This sulfur erupts out through Io’s many large volcanoes, rising hundreds of kilometers into space above the surface and then falling gently back down in an enormous spherical plume that took the Voyager mission scientists completely by surprise. ¬†As it falls, it freezes into a fine dust — effectively, snow. ¬†It creates vast white snowfalls on the moon’s surface, but they’re not our kind of snow. ¬†It’s¬†sulfur dioxide. ¬†In August of 2001, the Galileo spacecraft fortuitously flew through one of these plumes, directly sampling the snow. ¬†I don’t think you’d want to ski there, though. ¬†Apart from the totally absent atmosphere and the lethal radiation from Jupiter, there’s also the fact that you’re underneath the plume of an active volcano. ¬†Um . . . I think I’d rather brave the lines at Big Sky or Aspen than try for that.

NASA Science: Dashing through the Snows of Io

VENUS

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Okay, this one’s a bit more speculative, since the surface of Venus is nearly impossible to photograph shrouded as it is behind thick clouds of sulfuric acid and an unbelievably dense and hot atmosphere. ¬†The first landers to make the attempt were crushed before they reached the ground; the next ones, built like submarines, expired from the heat. ¬†So how could ¬†there be¬†snow?

In the image above, there are some surprisingly bright areas next to some surprisingly dark areas, and the bright areas are all high latitude. ¬†That’s a radar image from the Magellan spacecraft, so don’t assume the light areas are actually brightly colored; all¬†it really means is that they’re very reflective to radio wavelengths, while the black areas just soak it right up. ¬†Snow is very bright to radar, with its multitude of fine surface particles. ¬†And it’s not the only thing that can be bright, so bear in mind that maybe this one isn’t snow at all. ¬†But if it were, what material could possibly snow on Venus?

Scientists have speculated that it must be some kind of a metal compound forming a crystalline material, such as¬†coloradoite (a blend of mercury and tellurium) or tellurobismuthite (bismuth and tellurium). ¬†Heavy metals, which would be liquid in the lower elevations, but like water on Earth, would freeze at higher altitudes. ¬†Definitely don’t contemplate the skiing here, though, even if it really is snow. ¬†Venus is off limits. ¬†If it weren’t for the active volcanism, crushing atmospheric pressure, heat sufficient to melt lead, violent winds at high altitude, and sulfuric acid rain during the descent, Venus might actually be a nice place. ¬†ūüėČ ¬†But it’s not, and whether this stuff is heavy metal snow or not, it’s certainly a reminder that although some worlds can be surprisingly Earthlike, others are anything but.

SPACE.com: Heavy-Metal Frost May Coat Venus’ Mountains

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Beagle 2: Found!

This was widely rumored since Wednesday and announced publicly yesterday, and it’s awesome: Mars Reconnaissance Orbiter has located the lost Beagle 2 lander, Britain’s first and so far only attempt at landing on another world. ¬†And although the pictures can’t tell us exactly what happened, they do rule out some possibilities, and confirm¬†that whatever went wrong, the landing was actually successful.

In December of 2003, the Beagle 2 probe separated from Mars Express. ¬†The last signal heard confirmed safe separation, but nothing further was ever heard from it. ¬†That’s something every planetary lander team has on their mind, because an enormous number of things can destroy a mission at this critical stage. ¬†Did it land in the shadow of a boulder, big enough to shade the solar panels but yet too small for existing Mars orbiters to spot? ¬†(MRO would not arrive for several more years.) ¬†Did it land in a gully too narrow to allow the petals to open? ¬†Was it operating find, but unable to communicate? ¬†Or did one of the many different things that must all happen precisely on time in order to deliver it safely fail? ¬†Did the parachute fail to deploy? ¬†Did it deploy but become fouled? ¬†Was the heatshield to thin, or did it contain an undetected defect that let too much heat in? ¬†Did the backshell not separate? ¬†Did the airbags fail to deploy, leaving the probe to shatter on the surface of Mars?

The pictures rule out a lot of those possibilities, because they show it on the surface of Mars with at least two of its petals open. ¬†(This is near the limits of MRO’s abilities, so it’s hard to be sure if any other¬†petals failed to open.) ¬†And they believe they have also found the backshell and parachute. ¬†So whatever went wrong, it went wrong after landing — the landing system performed correctly.

MRO-Mars-Reconnaissance-Orbiter-Beagle-2-Lander-white-pia19106-br2It’s lovely to see the lost probe rediscovered like this! ¬†And if your’e wondering how they decided that these little specks of light were meaningful, well, JPL prepared a video to explain:

 

 

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Comet Siding Springs approaches Mars

Astronomers around the world are getting to watch an amazing event tomorrow — a very close flyby of Mars by Comet Siding Spring. ¬†Normally, this would be just a curiosity (since astronomers have ruled out the possibility of a collision) but this is a very fortuitous time for the encounter — two ground vehicles (Opportunity and Curiosity) and five orbiters (Mars Odyssey 2001, Mars Express, Mars Reconnaissance Orbiter, MAVEN, and Mangalyaan/Mars Orbiter Mission) are all ready to observe. ¬†MAVEN is particularly fortuitous; it’s specialized for atmospheric observations, which¬†makes it unusually well-equipped for this chance encounter with a comet’s tail.

Because yes, Mars is expected to pass through the comet’s tail. ¬†It’s pretty awesome, and the view from Curiosity in particular should be spectacular. ¬†(Curiosity is better equipped for night viewing, since it is nuclear powered and doesn’t need to conserve its batteries overnight.) ¬†NASA’s GSFC has released this video highlighting the experience:

It won’t just be the seven vehicles at Mars observing the comet. ¬†Other instruments, including the Hubble Space Telescope and STEREO-A, will also be watching, as will ground-based observers here on Earth. ¬†Amateurs with larger telescopes (8″ or better) and favorable weather will be able to follow the comet as it approaches and passes the red planet.

I can’t wait to see the pictures. ¬†ūüėČ

And if that weren’t exciting enough, the Orionids are starting up. ¬†That’s debris from Comet Halley, and it will peak in a few days. ¬†And on Thursday, many of us in North America (not all, alas) will be treated to a very nice partial solar eclipse. ¬†It’s a good week!

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Mars is a dynamic planet

On July 15, 1965, Mariner 4 flew past Mars and became the first spacecraft to return up-close pictures of the red planet — or, indeed, of any planet besides our own. ¬†Popular science and science fiction had longingly speculated about what life forms could exist on such a world, or how readily Mars could be colonized from Earth, even though the work of planetary scientists was already pointing towards a harsh, inhospitable place that was cold and dry and with very little atmosphere. ¬†The day Mariner 4 flew by, it seemed to settle all that — it returned pictures of a desolate, Moon-like world, covered in craters, devoid of rivers and fresh lava flows, dead and devoid of life.

Subsequent missions did little to dispel this impression, despite some brief interest in supposedly “artificial” features that some amateurs were identifying in NASA imagery from Mariner 9 and later the Viking orbiters. ¬†The twin Viking landers attempted to find life, but the results were inconclusive, proving neither life nor its absence.

Not until relatively recently was this idea challenged. ¬†Although the seasonal growth and retreat of the ice caps was obvious, and although global dust storms were clear even to Earthbound observatories, Mars was increasingly considered geologically dead, dry, and forever inhospitable. ¬†In the late 90s, that image started to change. ¬†Mars Global Surveyor detected dust devils, a more potent erosive force, and much more curious features that defied easy explanation. ¬†Albedo features (meaning dark patches) which might be geologically recent — perhaps even the sign of exploding dry ice geysers spewing sooty hydrocarbons across the dunes. ¬†Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter have since proved to the doubters that Mars is much more active — and much more interesting — than it was once thought. ¬†Streaks appeared and disappeared, the calligraphic scribblings of dust devils. ¬†The plumes once speculated to be recent features turned out to be seasonal as well. ¬†And MRO captured landslides in the act:

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Today, there are couple of stories in the news speaking to Mars’ truly dynamic nature. ¬†One, is a new crater. ¬†New craters have been spotted before, so this isn’t revolutionary, but it’s still pretty amazing. ¬†This one is one of the biggest of the new ones that have been spotted, and although it’s impossible to pinpoint the exact date of impact, it was sometime between July 2010 and May 2012. ¬†Because it’s so big and dramatic, it’s valuable for science, so NASA went and got a fresher image (photographed last November) and released it this week:

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But even cooler than that is the announcement of what may be liquid water on the surface of Mars, albeit briefly. ¬†For a long time, some scientists have maintained that certain flow patterns seen on dunes could be the result of liquid subsurface water flowing out from underneath as the frost melts in the spring. ¬†This being Mars, as soon as the meltwater flows out from the sand, it promptly boils away. ¬†It’s a controversial idea, but this new image gives it new support. ¬†If nothing else, it’s certainly one more point of evidence that Mars is not static at all.

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Of course, as amazing as those pictures are, none of them tops the really special one that Curiosity released last week. ¬†It’s of an exceptionally dynamic planet, and it’s very large moon. ¬†It is, of course, Earth in the night sky. ¬†ūüėČ

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Now, the Moon’s tough to see at this scale, so here’s the zoomed-in version:

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And that’s us. ¬†ūüėČ ¬†Mars looking back, while we look up.

 

 

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MRO has photographed Comet ISON!

With the federal government shut down, NASA has furloughed nearly its entire workforce. ¬†Fortunately, that doesn’t include the JPL staff, at least not yet, who are technically employed by Caltech. ¬†MRO successfully photographed Comet ISON during its closest pass of Mars today. ¬†This was an impressive achievement, since its “pushbroom” camera isn’t really designed for astrophotography; the telescope its attached to is excellent for this sort of thing, but the camera only collects a single line at a time. ¬†This lets them pack maximum resolution into the camera, but means it has to be swept across the target. ¬†When photographing Mars, this isn’t a problem; the spacecraft is always sweeping over the surface anyway. ¬†(This is also how spy satellites work; it’s great for a mapping spacecraft but not so great for much of anything else.) ¬†When photographing an astronomical target, it means they have to manually pivot the spacecraft to sort of sweep the camera across the target. ¬†On top of that, Comet ISON isn’t especially bright yet, so finding the right exposure settings was tricky.

Still, they did manage it!  And Emily Lakdawalla, whose Planetary Society blog is not funded by NASA, had the opportunity to post them for the world:

She reports that Opportunity and Curiosity also attempted to photograph the comet, but so far it doesn’t appear that the comet was visible to either of them. Their cameras are optimized for daylight surface photography, and ISON is not as bright as hoped; still, experts are working to see if they can tease anything out of the noise.

Mars Reconnaissance Orbiter achieves imaging of comet ISON from Mars

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