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Spirit Rolls on Mars
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Pound for pound, the amoeba is the most vicious animal on earth.
Pound for pound, the amoeba is the most vicious animal on earth.
Revisit Sojourner! (Score:5, Interesting)
I've been really hoping that one day they'll go back to the original Sojourner site and return that unit to Earth for analysis by NASA. They could gain valuable information as to what finally gave on that rover and use it to harden future rovers.
Sojourner was a great success as it lasted much longer than expected. Of course the cost of getting that unit back to Earth would be so high I'm guessing these are just nice dreams. C'est la vie.
Why was moving dangerous? (Score:3, Interesting)
However, I don't understand why they kept saying that moving the rover off the lander was "dangerous". I thought the rover was designed to be able to deploy even if the lander came to rest upside down. Instead it was right-side-up on level ground. The rover had to drive over the deflated balloon, but why was that more dangerous than just driving over the surface?
sPh
the waiting is over ---but (Score:3, Interesting)
Well I am glad to see that the thing did not get stuck on a balloon.
The chance of spirit getting stuck made me think. (For the next ones we make) Why not get some very small solid rocket engines and put them facing in all directions on this thing. If the rover gets stuck, then as a last resort they could try igniting one or more of these small rockets engines to try and dislodge the rover. These rocket engines would probably be the smallest model rocket engines (or smaller) since I would hope you wouldn't need much of a bang to move in the Martian gravity. They are also pretty cheap.
granted you'd only get one shot, but if it's a last resort it's better to have one shot then none.
flimsy looking (Score:1, Interesting)
A) It was capable of clearing debris off it's solar panels
B) it could right itself if overturned
C) it's propulsion system was designed to resist getting tangled up by parachutes and any other stuff around the landing spot
D) it Carrys a redundant solar array in case the solar array is damaged
E) it has to be able to "lift" itslef in any direction in case it gets stuck at an odd angle, 6 to 8 extendable rods facing different directions should be fine
Re:Revisit Sojourner! (Score:5, Interesting)
Wild-ass guess, but the wiper mechanism would probably get jammed by dust just about the time if could be useful in cleaning off the solar cells.
Seriously, even the scientists on the project wanted an RTG in the thing. They could have driven it around for *years* if they had. Instead, they got solar panels which (due to dust) have an expected lifetime of about 1/2 a year. Stupid environmentalism...
Meanwhile on VENUS ... (Score:5, Interesting)
Anyway, as reported by the BBC [bbc.co.uk], American scientist Don Mitchell [mentallandscape.com] found the original Soviet Venera probe data from the surface of Venus and he applied modern image processing techniques to it to produce some stunning new pictures [mentallandscape.com].
He also has a really fantastic site about the Soviet Venera probes [mentallandscape.com].
Rich.
Re:Revisit Sojourner! (Score:5, Interesting)
True, but dust and grit would eventually gum up most of the instruments and make wheels stick. The Viking landers didn't do much "moving" science after their first few months (after scooping soil, etc.) They mostly just tracked weather and looked around every now and then.
Making moving parts and instruments dust-resistant and/or cleanable would probably greatly add to the cost I would expect. In other words, power is only half the problem.
Further it costs something like 3 million USD a day to operate rovers (personell, communications, etc.) Thus, extended durations eat money in other ways.
And, it might be better science to have multiple short-distant rovers exploring a variety of marsographically[1] separated areas rather than one to two long-distance rovers. In other words, spend the money on quantity instead of duration.
And, "nuke" power cells are not politically popular due to possible launch crash risks.
[1] As opposed to GEOgraphically.
Short Mission Duration (given the cost) (Score:5, Interesting)
I've read that this mission is limited by the build up of dust on the rovers solar cells, reducing the power attained to the point where the rover can no longer function.
An obvious solution (to me, here in my comfy chair) would seem to be the ability of the rover to gently tilt and/or shake its panels to remove at least some of the dust.
Since the rover arrived with it's panels folded could it just fold and unfold them again to shake some of it off?
It seems such a pity for the mission to end for such a mundane reason since I presume it would otherwise continue until the batteries failed or physical wear/damage destroyed some key component.
Solutions for other missions spring to mind, perhaps:
- blowing the dust away with a small directed jet of compressed air.
- A small fan or brush on a simple arm.
- Speciali(s|z)ed tilt/shake schemes (as above).
- Raise the panels up on a windy day (without blowing over).
- Layers of protective film that can be peeled away.
Re:Revisit Sojourner! (Score:3, Interesting)
Anyway, some simple low-risk ideas:
* A small air blower jet to blow the dust off. After all, there is an atmosphere (albeit a thin Martian one) to work with.
* Tilt the panels and give them a gentle shake to get most of the dust off.
* Use an electrostatic coating to keep the fine dust from sticking.
As far as the batteries, couldn't they be deep-cycled to reduce their memory?
- dvd_tude
Re:Revisit Sojourner! (Score:2, Interesting)
dust removal -- static charge? (Score:3, Interesting)
I wonder if there might be some way to build up a charge to clean them off? Shaking or tilting probably wouldn't work -- look at the crap that gets stuck on your car over time and it doesn't come off at over 100km/h.
I've read that some sort of solar panel wipers or brushes wouldn't work as they'd scratch the surface, allowing less light to reach it.
The plastic film idea reminds me of the removable visor strips racecar drivers have on their helmets. Sounds like a good one. Patent? Boo, hiss ;-)
Re:Would it help if I got out and pushed? (Score:3, Interesting)
There are 3600 seconds in an hour, so Spirit would travel (3600/78) * 10 = 461.538 feet, or a little under 1/11 mile per hour. (0.08741, to be more exact)
Re:Revisit Sojourner! (Score:2, Interesting)
You mean they *aim* it toward the ocean. That does not mean it is guarenteed to head over the ocean.
An explosion of the rocket wouldn't even phase it (as past launch failures have shown).
That is pretty impressive if it turns out to be true. But I suppose skeptics will say that just because past explosions have not exposed it does not mean that future explosions won't either.
I agree that the risk is overplayed, though. Nasa understandably just does not want to deal with the politics of radiation if there are "close enough" alternatives. Their budget depends on public perception. Sometimes the public is a bit ignorant.
Re:Revisit Sojourner! (Score:4, Interesting)