Mars Rover Spirit Recovers From Steering Glitch

jangobongo writes "Spirit's steering glitch apparently cleared up on its own and engineers are still trying to understand what caused it. Meanwhile, the rover Opportunity found a cracked rock that may provide evidence of a second water event in the red planet's past."

Comments

The wrong side of the planet.

[eibhear]

"...are still trying to understand what caused it"

I suspect that Spirit stopped at a light on the wrong side of the planet and it went green while the locals were replacing those wheels with blocks.

Mind you, NASA's never going to admit that...

Éibhear

Overstaying their welcome

[RsD212]

Does anybody know off the top of their head how long past due these robots are? I remember them saying both machines would fail quickly, but they're still up and chuggin.

Im thinking NASA just gave those early death numbers to make themselves an easy goal to surpass. They havent exactly had a good track record lately.

Re:Overstaying their welcome

[Tablizer]

My understanding is that many contractor payments depend on the "warrentee" periods. If the rovers failed before that time and a particular contractor was related to the part of failure, then they don't get paid as much. I don't know the specific legalese of it all, though. It would make an interesting article if somebody could find the scoop.

Further, many of the parts were only tested under the 90-day assumption. For example, they may test thermal cycling on a circuit board 90 times to simulate 90 Martian days.

But one should also point out that the rovers are showing aches and pains. Spirit has a bum front wheel that requires excess power to run. Sometimes they turn it off and run the rover backward to avoid wearing it further. Opportunity seems to be having cable glitches due to worn cables from all the rocks it has drilled and imaged up close, and both rovers seem to have dust doors on instruments that seem to sometimes stick. Thus, it has not been exactly roses as far as the equipment is concerned.

Almost every other week I read about some new glitch that stumps engineers for a few days, sometimes halting science work. So far they have found workarounds, but the luck cannot last forever.

Padding the numbers

[mdp1173]

I don't think it was a case of overly padding their estimates, but some condervative assumptions turned out to be way off.

Originally, they thought dusk accumulation on the solar panels would be a much larger problem. They estimated that the panels would be sufficiently covered to not produce enough juice about 100 days in. It turns out, the panels just aren't getting all that dirty and the terrain is hilly enough that you can park the rover on a North-facing slope to increase power.

As for the other components, they spend so much time making them small and light that they invariabley are forced to use high quality components that go way past their L10 (the time at which 10% of a lot of parts will fail)

Overall, it's probably more good luck and proper planning than a tin-foil hat consipriacy to make NASA look good

Re:Padding the numbers

[Positive Charge]

I doubt it. The most likely scenario is that the engineering requirements extremely conservative in order to make the mission successful and save NASA from a black eye. The fact that they come out looking rosey is a side effect of their CYA program.

Re:Padding the numbers

[deglr6328]

What's even more amazing, I think, is that all the science and remote sensing instruments are still working fine!! The stuck heater glitch in Opportunity forced engineers to put it into "deep sleep" during winter months to prevent completely draining the batteries overnight but this has the unwanted consequence of also turning off all heaters in the warm electronics box. And the box, which also contains optics for the Mini-Thermal Emission Spectrometer was long ago expected to fall to >-60C overnight, shrinking an aluminum housing holding a crystal optic of potassium bromide (transparent to all IR light) enough to crack and destroy it...never happened though! Also, the microgrinding tool used to make boreholes in rock has worn much less than expected and the moessbauer spectrometers and microscopic cameras are still working perfectly after some concerns that one of thier plastic ribbon data cables might have been cracked while flexing during movement due to the extreme cold of martian winter. Amazing.

I love these plucky little guys

[hey!]

If anything, I think we should consider ramping up the rate and diversity of robotic planetary missions, rather than attempting a complex, dangerous manned mission with insufficient funding.

For one thing, we've already done a manned planetary mission -- to the Moon. There's more opportunities for useful new technological spinoffs in the robotic arena.

Re:I love these plucky little guys

[Tablizer]

consider ramping up the rate and diversity of robotic planetary missions, rather than attempting a complex, dangerous manned mission with insufficient funding.

How dare you outsource MY job to robots! Next you will be sending up starving Ethiopians because they are going to die soon anyhow and work for micro-peanuts.

- Pissed Astronaut

I'm surprised

[elmegil]

Nobody yet has suggested that it's martians performing experiments on the rover.