Tag Archives: Mars

Cassini’s Solar System Scrapbook

Cassini has completed its second-to-last ring plane crossing.  There’s only one more left before the final and fatal atmospheric entry.  But before it goes, Cassini completed a sort of family scrapbook of the solar system, by adding Neptune.  Here are some highlights of Cassini’s solar system scrapbook (which skips Mercury because it’s far too close to the Sun for Cassini to photograph):

Venus, Earth, and Mars

Venus, Earth and Mars, the only rocky planets easily observable from Saturn, as seen during the equivalent of a total solar eclipse around Saturn — Saturn is backlit by the Sun here. This was captured July 19, 2013.

Earth (and Moon), closeup from last image

This is a mega huge zoom in on the picture above.

 

Captured just before an Earth gravity assist maneuver, this is the Moon as seen on August 17, 1999. The spacecraft did not attempt to photograph the Earth during closest approach.

It’s worth also adding this. It’s the last image Cassini will ever take of Earth, captured April 12, 2017.

Jupiter

This was captured on December 29, 2000, while Cassini was grabbing a gravity assist boost from the giant planet.

Saturn

There’s really no end of good Saturn pics, but I quite like this one, taken last year as Saturn approached the summer solstice in its northern hemisphere.

Uranus

This blue planet against Saturn’s rings is not Earth. That little blue dot is the larger of the two “ice giants”, Uranus. I sincerely hope this is not the closest we’ll get to it in the 21st Century; it’s an astonishingly bizarre world that would seriously test a lot of basic science about planetary formation, magnetospheres, and so forth. This was captured April 11, 2014.

Neptune

This is the most recent addition to the scrapbook, a zoom-in enhanced version of an image taken Aug. 10, 2017, commemorating Voyager 2’s flyby on August 25, 1989 and the 40th anniversary of the mission’s launch on August 20, 1977. This is Neptune and its largest moon, Triton.

Pluto

Call it a consolation for not nabbing Mercury; Cassini captured this image of the dwarf planet Pluto on July 14, 2015, just as New Horizons was making its closest approach. (Naturally, New Horizons got much better pictures!)

 

It’s bittersweet, waiting for the end, but it helps to remember the amazing things Cassini has been doing.  Like Voyager 1 before it, Cassini is leaving behind portraits of our solar system.

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Five Years On Mars: Curiosity

Sunday was the fifth anniversary of Curiosity’s landing on Mars.  Like its predecessors, Curiosity has gone on to exceed all of its expectations, and is still going strong despite considerable wheel tread damage.  In honor of the occasion, NASA has released this time-lapse video (with a relaxing musical accompaniment) of all five years, as seen by the rover’s hazard avoidance cameras.  Note the times when it switches to driving backwards, to spread out the wear on its wheels.  😉

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20 Years at Mars!

One more post today, because this is an important one.  😉  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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Opportunity keeps on trucking

The rover that doesn’t know how to quit, Mars Exploration Rover B “Opportunity” has just departed “Cape Tribulation”, a feature on the rim of Endeavour Crater on Mars.  It’s spent the last 30 months at this location, conserving power over the Martian winter (since unlike Curiosity, it’s solar powered), and now it’s ready to move on.  The next destination is a nearby valley in the huge crater’s rim, called “Perseverance Valley”.  It’s a good name for a valley soon to be explored by a spacecraft 13 years into its 3-month mission.  😉  Opportunity will begin by studying the top of the valley, then move down it in the sort of pattern you’d expect a geologist to take while studying erosion and deposits that may explain how the valley was formed.

Here’s a final full-color panoramic look at Cape Tribulation:

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Curiosity’s drill is down

The Mars Science Laboratory “Curiosity” is an amazing vehicle in an exceptionally hostile environment, and it seems it is having some issues with its drill.  The drill itself is working fine, but the motor that extends the drill bit forward to touch the rock face is not cooperating.  As a consequence, Curiosity is on non-drilling duties while the JPL team analyzes the problem and decides what to try next.  Fortunately, it has a wealth of other instrumentation, so Curiosity has been far from idle.  Here’s one of the pictures it took while on its “drilling hiatus”:

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MRO’s high-res pictures of Schiaparelli are now available

The MRO team has now released high-res images acquired during a planned pass by MRO over the Schiaparelli landing site.  It does shed a little more light, although engineers will glean far more useful information from the 600MB of data it managed to uplink to Mars Express before perishing.  (The early indications from that, by the way, are that it was probably a software problem, not hardware, although ESA has not given more detail than that yet.  The most they’ve said is that some events were clearly commanded too soon.)

The new image clearly shows not only the impact site, but also the heatshield and and the parachute, still attached to the backshell.  Perhaps the most interesting feature is a lighter arc extending out from the Schiaparelli impact site.  This could be a debris trail left behind by a ruptured propellant tank exiting the spacecraft on impact.  It will certainly be subject to careful analysis in the coming weeks.

mro-hirise-esa-exomars-schiaparelli-rover-pia21131-br2

The MRO team plans another pass later, which will allow stereo imaging of the site.  This should help determine whether the black smudge is just a smudge or if its more of a crater.  If nothing else, in addition to the wealth of engineering data obtained during descent, this is a unique opportunity to advance impact science.

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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:

mars_reconnaissance_orbiter_view_of_schiaparelli_landing_site_large

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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