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The latest on Spirit…

There was a big news teleconference today, updating everyone on the situation with “Spirit”, the poor Mars rover that has been stuck in a sand trap for the past 6 months. I’ll paste the official press release in at the end here, but basically this was the news:

* Spirit is in big, big trouble, the worst she – or either of the rovers – has ever been in. It’s very possible that she might not get out of this dust trap, and will end her mission where she is now.

* It turns out that the rover actually drove over the lip of and part way onto a small, ancient, buried crater. When her left wheels broke through a layer of brittle “duricrust” covering the crater, they then sank into the talcum powder fine dust filling the crater beneath its crusty surface.  

* To make matters worse, there are rocks underneath the rover, one of which may or may not even be touching the rover’s underbelly.

* The MER team has decided that the best thing to do is to try and reverse the rover out of its current sandtrap, following its own tracks as it were. Driving forwards might just mean all the rover’s wheels get bogged down in the sand, instead of just the ones that are now.

* The first attempt to drive Spirit out of its trap – or “extricate” it – will be made on Monday / Tuesday next week. It is NOT expected that the rover will just “pop out” of the dust trap, and it’s likely that it will take weeks if not months to get Spirit out of where it’s stuck – if that is even possible. It might not be.

* We should know more about the rover’s progress late on Tuesday, when images taken will show how much / if the rover has moved.

So, there you have it. Spirit has been riding her luck for a long time, but her luck might finally have run out. The MER team were being very realistic about the situation – their rover is in deep, deep trouble, and they haven’t figured out a plan that would definitely work. But that doesn’t mean they’re going to stop trying! And, if the worst comes to the worst, and she is stuck, Spirit will still be able to do fantastic science until she stops working. She will be able to monitor the weather; check for seismic activity; study the powdery material she’s bogged down in; make astronomical observations. And, of course, take and send back even more breathtakingly beautiful images of the surface of Mars.

All we can do now is wait and cross our fingers that, for a change, Spirit gets some luck thrown at her, instead of having to fight tooth and nail for every inch she drives.

Big day Monday. Check back here for news.

Here’s the full NASA press release, with a lot more science in it…

News release: 2009-164                                                                      Nov. 12, 2009

NASA to Begin Attempts to Free Sand-Trapped Mars Rover

The full version of this story with accompanying images is at: http://www.jpl.nasa.gov/news/news.cfm?release=2009-164

PASADENA, Calif. — NASA will begin transmitting commands to its Mars exploration rover Spirit on Monday as part of an escape plan to free the venerable robot from its Martian sand trap.

Spirit has been lodged at a site scientists call “Troy” since April 23. Researchers expect the extraction process to be long and the outcome uncertain based on tests here on Earth this spring that simulated conditions at the Martian site.

“This is going to be a lengthy process, and there’s a high probability attempts to free Spirit will not be successful” said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. “After the first few weeks of attempts, we’re not likely to know whether Spirit will be able to free itself.”

Spirit has six wheels for roving the Red Planet. The first commands will tell the rover to rotate its five working wheels forward approximately six turns. Engineers anticipate severe wheel slippage, with barely perceptible forward progress in this initial attempt. Since 2006, Spirit’s right-front wheel has been inoperable, possibly because of wear and tear on a motor as a result of the rover’s longevity.

Spirit will return data the next day from its first drive attempt. The results will be assessed before engineers develop and send commands for a second attempt. Using results from previous commands, engineers plan to continue escape efforts until early 2010.

“Mobility on Mars is challenging, and whatever the outcome, lessons from the work to free Spirit will enhance our knowledge about how to analyze Martian terrain and drive future Mars rovers,” McCuisition said. “Spirit has provided outstanding scientific discoveries and shown us astounding vistas during its long life on Mars, which is more than 22 times longer than its designed life. ”

In the spring, Spirit was driving backward and dragging the inoperable right front wheel. While driving in April, the rover’s other wheels broke through a crust on the surface that was covering a bright-toned, slippery sand underneath. After a few drive attempts to get Spirit out in the subsequent days, it began sinking deeper in the sand trap. Driving was suspended to allow time for tests and reviews of possible escape strategies.

“The investigations of the rover embedding and our preparations to resume driving have been extensive and thorough,” said John Callas, project manager for Spirit and Opportunity at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We’ve used two different test rovers here on Earth in conditions designed to simulate as best as possible Spirit’s predicament. However, Earth-based tests cannot exactly replicate the conditions at Troy.”

Data show Spirit is straddling the edge of a 26-foot-wide crater that had been filled long ago with sulfate-bearing sands produced in a hot water or steam environment. The deposits in the crater formed distinct layers with different compositions and tints, and they are capped by a crusty soil. It is that soil that Spirit’s wheels broke through. The buried crater lies mainly to Spirit’s left. Engineers have plotted an escape route from Troy that heads up a mild slope away from the crater.

“We’ll start by steering the wheels straight and driving, though we may have to steer the wheels to the right to counter any downhill slip to the left,” said Ashley Stroupe, a JPL rover driver and Spirit extraction testing coordinator. “Straight-ahead driving is intended to get the rover’s center of gravity past a rock that lies underneath Spirit. Gaining horizontal distance without losing too much vertical clearance will be a key to success. The right front wheel’s inability to rotate greatly increases the challenge.”

Spirit has been examining its Martian surroundings with tools on its robotic arm and its camera mast. The rover’s work at Troy has augmented earlier discoveries it made indicating ancient Mars had hot springs or steam vents, possible habitats for life. If escape attempts fail, the rover’s stationary location may result in new science findings.

“The soft materials churned up by Spirit’s wheels have the highest sulfur content measured on Mars,” said Ray Arvidson a scientist at Washington University in St. Louis and deputy principal investigator for the science payloads on Spirit and Opportunity. “We’re taking advantage of its fixed location to conduct detailed measurements of these interesting materials.”

One Response

  1. […] Der aus dem Boden aufgewühlte grobe Sand („Ulysses“ im Bild der Front-Hazcam) ist der sulfatreichste, auf den irgendein Rover stieß; weiter rechts sieht es ganz anders aus. Und ein technisches Problem scheint zumindest gelöst zu sein: Das Flash Memory funktioniert wieder. Falls also am Ende gar nichts mehr geht: Als ortsfeste Wetterstation wäre Spirit immer noch nützlich. NACHTRAG: ein NASA Press Release anlässlich der Telecon – von einer „high probability“, dass die Befreiung fehlschlägt, war da aber nicht so explizit die Rede gewesen; dieser Artikel gibt den „spirit“ m.E. besser wieder. Auch: ein langer Artikel zu Spirits Lage vor der Telecon. NACHTRAG 2: weitere detaillierte Zusammenfassungen der Telecon hier und hier. […]

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