Spirit Mission 2009 and onward

[EarthlingX]

Not encouraging .. There's something i don't exactly understand: is there a weight on a blocked wheel ? Could it be lifted somehow ?

 

[EarthlingX]

Crater topography picture from the article of the latest Spirit discovery:
Sandtrapped Rover Makes a Big Discovery

 

[Boris_Badenov]

This is a little bit of MER trivia I just came accross. The actual Mars Exploration Rover Mission patch;

 

[MeteorWayne]

From Spaceflight Now:

http://www.spaceflightnow.com/news/n0912/09spirit/

Second wheel problem dims hope for stuck Spirit rover
BY CRAIG COVAULT
SPACEFLIGHT NOW
Posted: December 9, 2009


Problems with a second wheel on the Mars rover Spirit's right side have decreased the already slim possibility that the rover can free itself from a sand trap and return to roving operations.

Jet Propulsion Laboratory engineers this week shifted operations from freeing Spirit to instead diagnosing the new wheel problem which would be critical in getting the rover unstuck.....

Spirit's right front wheel failed early in the mission following its landing in January 2004, and now its right rear wheel has also stopped rotating normally.

The new problem has left the rover with only one good drive wheel on its right side for further attempts to free all of its left wheels that have been mired in a soft, slippery volcanic powder for six months.

 

[MeteorWayne]

SDC article from Tariq Malik, Managing editor:

Excerpt:

After months stuck fast in deep Martian sand, NASA's embattled rover Spirit is facing a debilitating wheel problem that has slowed its escape efforts and could paralyze the long-lived robot.

Spirit has been trapped wheel-deep in sand for nearly eight months and engineers on Earth have been spinning the Mars rover's wheels in recent weeks to try and force it free. But the rover's right-rear wheel has been stalling, and now may be broken for good.

"These wheel stalls have been such a complication, that we really haven't gotten started," said rover project manager John Callas of NASA's Jet Propulsion Laboratory in Pasadena, Calif., in a recent interview on Spirit's escape attempts.

Recent tests "continue to indicate a troubled wheel, which may leave the rover with only four operable wheels," mission managers said Thursday in a status update.

.....


NASA engineers are unsure if they can free Spirit with only four working wheels. The team is on the clock, too. The rover's current position and tilt aren't favorable for surviving the next southern Martian winter, which starts in May 2010.

http://www.space.com/missionlaunches/09 ... rover.html

 

[MeteorWayne]

Clock is Ticking on Spirit...

More not good news on Spirit from spaceflightnow::

http://www.spaceflightnow.com/news/n0912/16spirit/

The clock is ticking for stalwart Spirit rover

Spirit is now in an unfavorable orientation to collect sunlight for power production during the approaching Martian winter. Officials think the rover's chances for survival are slim at its current location.

"Now is the time to do something because we have the energy to do something. If we wait too long, we will have fewer and fewer options," said John Callas, project manager for the Spirit and Opportunity rovers at the Jet Propulsion Laboratory in Pasadena, Calif.

 

[bushwhacker]

time to fold up the wheels and settle in for a nice long nap.. great run lil rover

 

[pberrett]

I don't how how strong the arm is but I think it would be worth risking the instrumentation on it to try and lever the rover out of its current precarious position.

I would imagine that the arm must have some degree of strength in order to be able to drill into rock. Even if not the arm could be commanded to push against the soil from the rear whilst simulaneously rotating the wheels. That might give sufficient extra force to move forward a little. The arm might not be strong but might give some degree of sturdiness to help give the front wheels grip.

Alternatively perhaps the arm could gently sweep aside soidl forward of the rover to clear a path for it to move along?

Its a risk but worth it if the rover can be freed.

Regards Peter

 

[MeteorWayne]

As has been discussed here repeatedly before, the arm is far to weak to provide any help is shifting the mass of the rover.

 

[EarthlingX]

This article might be a food for optimists:
Spirit Broken Wheel Spins Again After Three Years

Spirit's right-front wheel, which had stopped operating in March 2006, revolved with apparently normal motion during the first three of four driving segments on Sol 2117 (Wednesday, Dec. 16) but stopped early in the fourth segment of the drive.

...

The drive conducted on Sol 2117 had been planned for one sol earlier, but was delayed after analysis of the Sol 2113 test led to discovery of a new electrical issue on Spirit.

Engineers learned that a persistent voltage now exists between the rover electric ground and the rover chassis where no voltage should exist. This condition might be related to problems with the right-rear wheel.

...

This suggests the unusual electrical behavior is associated with the rover motor controller board since the behavior is seen with all 10 motors associated with that electronics board. The rover has other motors not related to the wheels, but the persistent voltage has not been associated with any of those.

This is promising, right ?

 

[pberrett]

As has been discussed here repeatedly before, the arm is far to weak to provide any help is shifting the mass of the rover.

Even if it exerts just a little pressure that is at least something.

Further shifting the weight of the arm from one side of the river to the other might increase the traction on the wheels that have better grip.

In order to drill into rock the arm must nonetheless be able to maintain a given level of pressure on a rock. If it can find a nearby rock maybe it coudl push a little against it?.

cheers Peter

 

[MeteorWayne]

Dec 31 update from NASA:

http://www.nasa.gov/home/hqnews/2009/de ... Year6.html

NASA's Mars Rover Has Uncertain Future as Sixth Anniversary Nears PASADENA, Calif. -- NASA's Mars rover Spirit will mark six years of unprecedented science exploration and inspiration for the American public on Sunday. However, the upcoming Martian winter could end the roving career of the beloved, scrappy robot.

Spirit successfully landed on the Red Planet at 8:35 p.m. PST on Jan. 3, 2004, and its twin Opportunity arrived at 9:05 p.m. Jan. 24, 2004. The rovers began missions intended to last for three months but which have lasted six Earth years, or 3.2 Mars years. During this time, Spirit has found evidence of a steamy and violent environment on ancient Mars that was quite different from the wet and acidic past documented by Opportunity, which has been operating successfully as it explores halfway around the planet.

A sand trap and balky wheels are challenges to Spirit's mobility that could prevent NASA's rover team from using a key survival strategy for the rover. The team may not be able to position the robot's solar panels to tilt toward the sun to collect power for heat to survive the severe Martian winter.

Nine months ago, Spirit's wheels broke through a crusty surface layer into loose sand hidden underneath. Efforts to escape this sand trap barely have budged the rover. The rover's inability to use all six wheels for driving has worsened the predicament. Spirit's right-front wheel quit working in 2006, and its right-rear wheel stalled a month ago. Surprisingly, the right-front wheel resumed working, though intermittently. Drives with four or five operating wheels have produced little progress toward escaping the sand trap. The latest attempts resulted in the rover sinking deeper in the soil.

Also released Dec 31:

http://www.nasa.gov/mission_pages/mer/i ... 91231.html

Spirit attempted to turn all six wheels on Sol 2126 (Saturday, Dec. 26, 2009) to extricate itself from the sand trap known as "Troy," but stopped earlier than expected because of excessive sinkage. Telemetry indicates that the rover moved forward 3 millimeters (0.12 inch), left 2 millimeters (0.08 inch) and down (sinkage) 6 millimeters (0.24 inch). The right-front and right-rear wheels did not move.

This four-frame animation, which rover drivers use to aid evaluation of the drive , shows wide-angle views northward from Spirit's front hazard-avoidance camera. The most obvious change is in the position of shadows, a change unrelated to the wheel's movement during the drive. Changes in the soil in front of the left-front wheel can be seen as the sequence progresses, but there is very little net movement of the rover

 

[earth_bound_misfit]

That doesn't look good at all :shock:

 

[pberrett]

Maybe the arm wouldn''t have enough strength to lift the rover up.

But would it have sufficient strength to gently sweep the sand in front of the wheels away from side to side thus making a path/furrow that the wheels could travel down?

In a similar fashion maybe the arm could sweep some small rocks down under the wheels to help provide extra traction?

Regards Peter

 

[MeteorWayne]

Emily Lakdawalla of The Planetary Society is sadly reporting this on Sol 2135 (yesterday):

"I'm very sad to report that the Mars Exploration Rover mission has formally given up on getting Spirit out of the sand trap at Troy before the Martian winter arrives; she's now likely embedded forever. But we're far from the end of the mission. They're still working to get her solar panels slightly more favorably tilted for winter survival, and once they stop rolling they actually have a lot of ideas for valuable science that can be done with Spirit as a lander. Think about this: even if this coming winter kills Spirit, it'll still have a longer mission as a lander than Phoenix did!"

Here's the latest full TPS update on Spirit, with a few Oppy notes at the end. As usual, it's a superb summary:

http://www.planetary.org/news/2009/1231 ... pirit.html

 

[centsworth_II]

Emily Lakdawalla of The Planetary Society is sadly reporting this on Sol 2135 (yesterday):

Still waiting to hear where she got that from, but this is a question to and response from Scott Maxwell, one of the drivers involved in Spirits efforts:

"Emily says you've given up on FreeSpirit, at least for the winter. True?" -- sgendreau

"Tried another #FreeSpirit idea yesterday (not downlinked yet); still have at least six or eight potential tricks up our sleeves." -- marsroverdriver

Unless Emily has some inside info that even one of the insiders doesn't have, it looks like they'll still be trying for awhile.

 

[bearack]

Maybe the arm wouldn''t have enough strength to lift the rover up.

But would it have sufficient strength to gently sweep the sand in front of the wheels away from side to side thus making a path/furrow that the wheels could travel down?

In a similar fashion maybe the arm could sweep some small rocks down under the wheels to help provide extra traction?

Regards Peter

I was actually thinking the same thing. Push some rocks, small and large into the trench to offer some additional traction. What's to lose?

 

[MeteorWayne]

They'll keep trying as long as they can for sure. However, if you look back a page or so, there is a decision point coming up as to whether to continue funding, and if so, how much. At that point, if no prgress has been made, I suspect they might have to turn off the money (and data capacity) spigot and concentrate on Oppy and future missions. Just the pragmatist in me again They can still check in for whatever observations they can make, but it might be hard to justify the same level of funding.

We'll see what happens over the next few weeks.

 

[3488]

Sol 2,118. Shows how entrenched MER A Spirit is.

Andrew Brown.

 

[bushuser]

sand traps

Off topic, but...Surely there are sand traps like this on the moon, where we hope to soon have some roving explorers, maybe even some heavy equipment. Future wheeled vehicles need some planning to prevent this permanent entrapment. I know tracked vehicles come with a different set of problems. Maybe a set of thrusters would allow for an emergency hop. Don't we wish Spirit's arm had the necessary power to lift one side of the rover!

 

[MeteorWayne]

Emily Lakdawalla has backed off from her previous statement:

"I want to apologize for some confusion I created when I got confused earlier this week about the current status of the Mars Exploration Rover Spirit. Although Spirit's outlook remains gloomy and she's still buried in soil at Troy, JPL has not (as I said earlier) ended extrication efforts for the season in order to focus on winter survival. That decision may yet be made, but it hasn't yet; as of last night, rover driver Scott Maxwell told me, "extrication attempts are ongoing, at least for now."

It's been two months, now, that extrication efforts have been going on. It's discouraging that the rover isn't out of the trap. But I think I am actually more confused than I am discouraged. Mars -- and Spirit, ever the drama queen -- keep throwing curveballs at us on Earth. Almost none of the drives have proceeded to completion as commanded. Sometimes they abort for reasons that make perfect sense (like when Spirit was commanded to turn the wheels in place, but had to quit when the soil packed around one wheel proved too resistant to wheel motion). Most of the time, though, weird stuff happens: the right rear wheel up and died. The right front wheel moves -- sometimes. Weird readings indicate transient electrical problems. And so on. My head hurts trying to think about all the different variables they're dealing with."

http://www.planetary.org/blog/

 

[samkent]

You don’t need the are to lift the weight of the rover. Has you car ever been stuck in the snow? One person pushing with the spinning tires is often enough to move the car.
Why not combine the drive command with a push type command? Maybe they could get an inch per day. That’s more then they are getting now.

I would rather sacrifice further use of any of the arms tools in favor of getting back on the road (so to speak). The arm isn’t doing much good any way.

 

[centsworth_II]

...Why not combine the drive command with a push type command?...

The arm and wheels cannot move at the same time. Also, the arm could only push in the opposite direction of the current drives. Driving in the opposite direction pushes the rover into worse surface conditions.

 

[samkent]

The arm and wheels cannot move at the same time.

That's hard to believe. Perhaps a software block as a safty feature. Change the software until Spirit gets back to hard ground. Either that or look at the same rocks until winter ends the mission.

 

[centsworth_II]

"...because the motor control board is shared between the arm and the wheels, we can't actually push while driving."
--- Scott Maxwell, rover driver

See the comments after this blog post.