Mars Rover Spirit Down a Wheel 272
riflemann writes "NASA is reporting that two years into its 90-day mission, Spirit has lost one wheel and is now running on five wheels, dragging the broken wheel. With this reduced mobiity, the rover still needs to make its way to a slope where it can catch enough sun over the Martian winter to keep it operating. 'Even though the rovers are well past their original design life, they still have plenty of capability to conduct outstanding science on Mars.', says project leader Dr. John Callas."
Tis but a scratch (Score:5, Funny)
Re:Tis but a scratch (Score:5, Funny)
We thank thee Lord, that in thy merc-
C'mon ya pansy (Score:5, Funny)
Re:C'mon ya pansy (Score:2, Funny)
Conversation I never Overheard (Score:5, Funny)
Martian2: nah. It seems to have such a drive for life.
Re:Conversation I never Overheard (Score:5, Funny)
Re:Conversation I never Overheard (Score:3, Funny)
Late Breaking News: (Score:5, Funny)
A sense of triumph swept our fair red world today when reports came in that the Grand Army of the Council had damaged one of the robotic invaders from the evil blue planet. K'Breel, speaker for the Council of Elders, made the following comment:
When a journalist suggested that the terrible monstrosity had merely worn out one of its locomotive rotators, K'Breel had the traitor's gelsac mutilated immediately.
Apologies to TripMaster Monkey.
Re:Tis but a scratch (Score:3, Funny)
Not so surprising (Score:2, Funny)
Re:Not so surprising (Score:5, Insightful)
Re:Not so surprising (Score:3, Funny)
Re:Not so surprising (Score:2, Funny)
Still a tossup - Rovers dead before Vista released (Score:5, Funny)
when and if Vista is ever released.
Re:Still a tossup - Rovers dead before Vista relea (Score:3, Funny)
Re:Still a tossup - Rovers dead before Vista relea (Score:2)
Re:Still a tossup - Rovers dead before Vista relea (Score:5, Funny)
Re:Still a tossup - Rovers dead before Vista relea (Score:3, Informative)
The chips are fairly cheap and have lightning fast floating point calculations via alti-vec. They are also very easy to program for.
NASA claimed they would only work for 90 days due to the high iron conten
Re:Still a tossup - Rovers dead before Vista relea (Score:2, Informative)
Re:Still a tossup - Rovers dead before Vista relea (Score:5, Informative)
No radiation hardened space suitable chips are "cheap." Expect to spend tens, if not hundreds of thousands of dollars per CPU.
That's not to say it's not a great chip for what it does, but come on...
Re:Still a tossup - Rovers dead before Vista relea (Score:3, Interesting)
I was also quoting NASA as for them being cheap. When the landers were on there way they said in interviews on TV that they were cheaper chips......looking at wiki it is hard to find many other RAD hardened chips.
Re:Still a tossup - Rovers dead before Vista relea (Score:4, Funny)
Well, future rovers could carry around little Roombas to run around and vacuum off the top of their solar cells.
Re:I'll take the Offtopic hit for this (Score:2)
The extra credit question is: How did I get "<br>" to show up instead of being interpreted as HTML?
Cheers,
Dave
Re:I'll take the Offtopic hit for this (Score:2)
No. You use < and > which means <br> converts to <br>.
Or you can use "extrans" mode, which is what I did for this post
At first read, I get dissapointed (Score:5, Insightful)
a) it was originall a Crackerjack prize or some other freebie.
b) it was 5 years into it's projected one year battery life.
At this point he gave it a solemn memorial service and kept it in a revered place (I think he may have buried it).
Whenever they finally die, I hope that they find an honored place in whatever museum the future Mars colonists decide to set up.
R2.0
Re:At first read, I get dissapointed (Score:3, Interesting)
Re:At first read, I get dissapointed (Score:2)
This is the same reason I prefer an 80,000 mile powertrain warranty over a 40,000 mile warranty when buying a car - not because any modern car is likely to last under 80,000 miles, but because I figure the one with the longer warranty is more likely to go 150,000+.
Re:At first read, I get dissapointed (Score:3, Insightful)
Re:At first read, I get dissapointed (Score:2)
I worked for GM as CAC manager for a couple months, trust me, that assumption is not one that you want to make.
For other car companies, it may be advertising, for GM, it is something to strive for.
Re:At first read, I get dissapointed (Score:2)
I thought it was pretty plausible that they expected them to only last 90 days simply because of the dust problem, that it would cover the solar cells. For a while, it didn't even look like they would last a month due
Re:At first read, I get dissapointed (Score:2)
Re:At first read, I get dissapointed (Score:3, Informative)
After 90 days, they went and asked for additional money. What's NASA going to do, stop running the rovers because they're over budget? Of course not. Unfortunate
Or like in Star Trek Enterprise... (Score:2)
Re:At first read, I get dissapointed (Score:5, Funny)
Kirk: Mr Scott I-
Scotty: But you don't have 8 weeks, so I'll do it for you in 2
Kirk: Mr Scott, have you always multiplied your repair estimates by a factor of four?
Scotty: Of course, Admiral, how else can I keep my reputation as a Miracle Worker?
Kirk: Your reputation is secure, Mr Scott.
If I recall, this dialoge was in ST:3, but I'm not sure of that.
Re:At first read, I get dissapointed (Score:2)
PHB Response (Score:2, Funny)
What are you talking about? Their projections were WRONG by an order of magnitude. They should all be fired for failing to predict the life-span of these rovers accurately.
Re:PHB Response (Score:2, Funny)
Re:PHB Response (Score:2)
But that was hilarious. Hats off.
It's not "dragging" the sixth wheel (Score:2, Informative)
Additionally, there's only been a couple days worth of data -- noone really knows why the motor stalled.
Re:It's not "dragging" the sixth wheel (Score:5, Informative)
http://marsrovers.jpl.nasa.gov/gallery/all/2/f/78
Re:It's not "dragging" the sixth wheel (Score:2)
Re:It's not "dragging" the sixth wheel (Score:2)
Re:It's not "dragging" the sixth wheel (Score:2)
the most obvious is one with a worm gear drive (often seen inside low rpm gearmotors)
Re:It's not "dragging" the sixth wheel (Score:2)
Re:It's not "dragging" the sixth wheel (Score:2)
Re:Your sig: "annulment" (Score:2)
Re:It's not "dragging" the sixth wheel (Score:5, Informative)
I beleive they have a video about the last time the wheel was left dragging. They did some test-bed simulations of an Earthly rover copy. Page down to the "Driving Uphill Backwards" portion, about half-way down the page:
http://marsrovers.jpl.nasa.gov/gallery/video/spir
Re:It's not "dragging" the sixth wheel (Score:2, Interesting)
Hold on, Tex. The older problem was that it drew too much current. It still worked and they used it for occasional tight maneuvering. Now it appears to be all-the-way gone. However, it went back to normal for a while before it completely failed. It is even possible the problems are not related.
The speculation was that lubricant was not spreading around enough, creating friction, and that the problem went away because lubricant finally dripped into t
Only lost 1 wheel? pfft (Score:5, Funny)
http://youtube.com/watch?v=OZqVvYkCe68 [youtube.com]
Re:Only lost 1 wheel? pfft (Score:2)
Pfft, try just ONE leg... (Score:5, Funny)
Re:Only lost 1 wheel? pfft (Score:5, Funny)
heh, sorry.. had to make the joke...
Re:Only lost 1 wheel? pfft (Score:3, Interesting)
exploration will continue (Score:5, Insightful)
Re:exploration will continue (Score:2)
Re:exploration will continue (Score:2, Funny)
Didn't HAL (or Dave Bowman, or whomever the aliens were) tell us, "ALL THESE WORLDS ARE YOURS EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE."?
Re:exploration will continue (Score:2)
Too late buddy. Most current scientific theories on such things say that nature has more then had plenty of opportunity (and the means) to send life one way, or even both ways. So it's quite possible one of our planets (if not both) were contiminated by the other.
Re:exploration will continue (Score:2)
Which many say won't be possible until we get to Mars.
Even if there is only a 1 in 1000 chance of a human-ending bug on coming back from Mars, that is still too high for comfort.
The existence of there being life at all on Mars is only theoretical, so much so that you won't get a statistic of any sort (well, of any reliability, I'm sure plenty of scientists have made claims, but I doubt they agree with each other within any realistic range), let alone t
Cold (Score:4, Interesting)
Its almost winter in the southern hemisphere of Mars. I wonder if there is a chance that a contact has contracted in the cold enough to break off power to this motor. Who knows? Spirit has been lucky before. Perhaps this wheel will start working again in the summer.
Failing that I am available to fix the broken motor, assuming that NASA can provide transportation :)
Re:Cold (Score:3, Funny)
Re:Cold (Score:3, Funny)
In other words, they'll use a large trebuchet to get you there (or somewhere... either way, it will be fun!)
Re:Cold (Score:2)
I don't think that sig means what you think it means. To illustrate: what it actually means is, "Big brother -- hey, you lot, take a look!" If you want it to mean what I think you want it to mean, try "magnus frater te spectat."
Re:Cold (Score:2)
Linky! [everything2.com]
Re:Cold (Score:2)
They'd be happy to send you! (Score:2)
Late breaking news? (Score:2)
2 years into a 90 day mission... (Score:5, Funny)
Shoulda got the AAA Extended Service Plan (Score:5, Funny)
Failed brushes? (Score:5, Interesting)
(My experience with brushed and brushless motors comes from R/C planes, where a brushless motor is sometimes twice as powerful and 50% more efficient than a similarly sized brushed motor. Of course, a large part of this is that the brushed motor is dirt cheap, made cheaply in every way, and the brushless motors are of higher quality, but even so, even when comparing high quality stuff (and not cheap speed 400 can motors) the brushless are signifigantly better.)
Re:Failed brushes? (Score:2, Insightful)
Re:Failed brushes? (Score:2)
Re:Failed brushes? (Score:3, Informative)
Maxon [slashdot.org] makes lots of motors, both brushed and brushless. If you look at their web site, you'll notice that most of their new motors are brushless.
As for the list of applications you gave, I'm guessing that new designs of these products use mostly brushless motors now, if only for the reason that they last longer and the brushes aren't ground down to dust over time.
Re:Failed brushes? (Score:5, Interesting)
Re:Failed brushes? (Score:5, Interesting)
I'm sure they went brushed for a variety of very good reasons. The technology of brushless was available when the rovers were designed, and I can't imagine NASA not seriously considering them.
Re:Failed brushes? (Score:2)
Hm -- what things don't work great without a lot of shielding in space?
I'm not saying it couldn't be done, I'm saying it might've been the right choice given size and electronics-reliability constraints.
Also, as a rebuttal to the "90 days was an intentional understatement", I'd put forward that it was probably an understatement, and that the 2-year mark is probably beyond design spec. What
Re:Failed brushes? (Score:2)
You're right, I attended a presentation by Steven Squyres, Mars Rover PI. During the QA I asked exactly this question and he pretty much said the same thing. Their goal was 90
Re:Failed brushes? (Score:5, Informative)
This stuff isn't rocket science. Even things like scooters [rascalscooters.com], Segways [segway.com] and electric cars use similar technology.
I'm guessing that the AC who posted in this thread was right on -- that NASA used brushed motors because they've used them in the past and they worked fine then, so they'll work fine now -- when you're spending billions of dollars on things that can't be repaired in the field, you tend to stick with what's tried and true rather than what's 15% more efficient but not quite so well tested. I suspect that future rovers will have brushless motors, however.Re:Failed brushes? (Score:2)
as a general rule of thumb, electronic bits are more reliable than mechanical bits.
Does your general rule include high radiation environments? Mars has an atmosphere, but not much of one.
Re:Failed brushes? (Score:3, Interesting)
As a general rule of thumb, ionizing radiation doesn't usually immediately destroy electronic components (at least those that we've hardened for space duty) when it hits it. The damage can accumulate over time, or it can cause a `glitch' changing a 0 to a 1 in a digital circuit (which can do nasty things like crash computers (which is taken care of by watchdog systems that initiate a reboot when
Re:Failed brushes? (Score:2, Insightful)
Their budget was for 90 working days. That is how the contracts stipulated payment. Further, the solar panels have been cleaned repeatedly by dust devils. Experience with the 2 Viking landers showed that dust builds up pretty quickly on probes and they understandably factored this
Re:Failed brushes? (Score:2)
Dust buildup was supposed to render them useless after a while; luckily it seems some wind solved that problem for them.
The Rovers both carry a massive weight of non-rechargeable batteries (alkaline cells, or something) and very little of rechargeable cells. Unable to even discard the spent battery cells. The rovers have been carrying the spent cells ever since they ran flat, doing horrible things to the power to weight ratio and
I'm still amazed.... (Score:3, Insightful)
Re:I'm still amazed.... (Score:5, Insightful)
The temperatures, radiation, dust, vibration... these are very harsh environmental variables. It is just amazing that they are still running. I'm sure that NASA is still as amazed as we are, and pleased to be continuing the scientific research at what amounts to a budget bonanza.
You are most probably right in thinking that what was learned this time around will be incorporated in the next planetary exploration vehicles, and a longer lifetime expectation will be part of that. In line with that, recent NASA un-manned missions have been incredibly successful. I look forward to more solar system exploration, and also to commercial exploration based on NASA work.
Now that we know how to build robots to explore Mars, we can build them to explore other planets, and that ion engine thing is a Trekie's dream. The expectation bar is rising, and that is a good thing. The X-prize and similar efforts are creating huge scientific 'wealth' for all to use. Its all very cool.
all alone in the cosmos (Score:3, Interesting)
I guess we've given up on artificial intelligence, but I rather think what we altogether thought was a mind of information is actually a mind of situation and evolving spirit that simply exists in the moment. If that be true, even an Ant could have artificial intelligence.
Its interesting we drive these things into the ground, or until they run out of power, or we loose interest.
It may be lame, But I'd think it might be more interesting in the long run to upload a final survival program into these critters and turn them loose.. perhaps in the long run we'll come to those ideas and terms. Perhaps years from now when astronauts decide to land there they really will find martians!
Of course if we have a nuclear or biological melt down, then perhaps they will out live us.
There was a SciFi story long ago called NightFall.. it would make an interesting animated short or story to tell the story from the rovers perspective... and in the end they are given their freedom and continue to look up at the night to the twinkle in the sky where their makers live, and then.. they loose contact, perhaps they merely lost interest in their creations.. or perhaps the makers are no more, and they truly are all alone.. and as the cold surrounds and grips them they fold up their solar wings preparing for another martian winter and the rovers go to sleep.. perchance to dream.. of other worlds.
The Truth... (Score:5, Funny)
Even if it can't make it up the slope... (Score:4, Interesting)
Surely when the Martian winter comes to an end, and the area it's in is flooded with sunlight again, the solar cells could still work, the battery could recharge, and it could wake up?
Or did nobody think about a cold restart?
Re:Even if it can't make it up the slope... (Score:5, Informative)
The principle investigator for the missions has written a book, "Roving Mars", that really is worth the read.
Re:Even if it can't make it up the slope... (Score:5, Informative)
Bingo. Indeed, it's even worse than that: if you can't run the heaters, all of the electronics undergo more extreme thermal cycling. This causes components to contract, flex, break, etc. Several critical components -- e.g., the CPU -- have no redundancy; if one of those goes, the whole rover goes.
This failure is the most dangerous thing to happen to Spirit since the flash anomaly on sol 18, when we effectively lost contact entirely for several days. Frustratingly, we're within sight of a safe haven -- only about a football field away -- but we might not be able to get there. Some people on the team think that if we have to drag a wheel, we can't climb the slopes we need to climb to make it to safety. I would just hate for Spirit to go this way; it would be like dying of thirst within sight of water, and she deserves better. (On the other hand, one thing I've learned is this: never bet against the rovers.)
Agreed! And since Steve's such a great guy, I'll linkify [barnesandnoble.com] that. :-)
Also looks like it's coming out in paperback [barnesandnoble.com] soon.
good point (Score:2)
And the book is on my buy list, now, since you're like the 4th person to tell me it's good.
Thanks.
Re:Even if it can't make it up the slope... (Score:2)
Pit Stop (Score:5, Funny)
Ten seconds! Go!
I am saddened... (Score:4, Funny)
though pain it does not feel.
Now it limps along the Martian soil,
alone in a great vastness of red sand and rocks.
I hope it reaches the top of the slope,
else alas for naught will it toil.
For in that vast desert there's no telephone box.
Nor much chance for hope.
Like the injured lone explorer,
Oh! What a horror!
it will suffer its demise,
Alone on that alien world,
Its nearest neighbor far away,
as no one hears its cries.
The wrath of Mars is unfurled,
And there alone will it lay.
Re:I am saddened... (Score:2)
Well, The Doctor could whip on over in his TARDIS and make a quick rover^w house call!
Tire tracks, not water (Score:5, Insightful)
Imagine the tension if we found ourselves face-to-face with a foreign martian rover!
Re:Tire tracks, not water (Score:4, Informative)
You can get your Martian weather forecast here: http://astro.sci.uop.edu/~harlow/weather/mars.htm
One Wheel Dragging? (Score:4, Funny)
Overtime? (Score:4, Funny)
Talk about overtime, you think the rover gets time and a half now?
Re:Great... (Score:2, Funny)
Re:Great... (Score:5, Funny)
Re:Martian AAA (Score:2)