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Mars Lander Faces Slow Death
Posted by
Soulskill
on Wed Oct 29, 2008 04:12 AM
from the this-lander-will-self-destruct-in-five-months dept.
from the this-lander-will-self-destruct-in-five-months dept.
Riding with Robots writes "It's the beginning of the end for the Phoenix Mars Lander. As winter approaches in the Martian arctic, NASA says it's in a 'race against time and the elements' in its efforts to prolong the robotic spacecraft's life. Starting today, mission managers will begin to gradually shut the lander's systems down, hoping to conserve dwindling solar power and thereby extend the remaining systems' useful life. 'Originally scheduled to last 90 days, Phoenix has completed a fifth month of exploration in the Martian arctic. As expected, with the Martian northern hemisphere shifting from summer to fall, the lander is generating less power due to shorter days and fewer hours of sunlight reaching its solar panels. At the same time, the spacecraft requires more power to run several survival heaters that allow it to operate even as temperatures decline.'"
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NASA (Score:5, Funny)
Honestly, as an Australian, it's great to see NASA in the news for something which can't be summarised as: "It blew up".
Needs more funding IMHO.
Re: (Score:3, Funny)
Re:NASA (Score:5, Funny)
NASA may have a better record with robots, but ESA has never lost a single astronaut. Admittedly that is through lack of trying...
Parent
Re:NASA (Score:5, Funny)
Pfft. Anyone with security clearance over Top Secret knows that Beagle made it successfully and recorded 13 seconds of video [wikipedia.org] before being destroyed. Has NASA's probes ever found aliens? I think not.
Parent
Re:NASA (Score:4, Funny)
Of course they haven't. Unless they run into another lander, they can only encounter natives.
Parent
To Boldly Go (Score:3, Funny)
"And we stopped being a "colony" as of Federation... 1901"
Australia is part of the Federation?
Cool
Do they have Warp Drive?
Re:To Boldly Go (Score:5, Interesting)
Parent
Re:NASA (Score:4, Insightful)
Parent
Re:Oooh aaahhh (Score:5, Funny)
Parent
Re: (Score:3, Interesting)
As a Brit, obviously i "was" disappointed at the time with the loss of Beagle 2. But the success of NASA's wonderful landers have more than made up for it. The huge contribution to science and learning, in this time when all other news is about the Credit Crunch and global meltdown.
As a kid at school, I always admired America, specifically NASA, watching the space shuttles, Rockets, Apollo, etc. When Challenger exploded, it was at the time a horrific and sad sight for a young child to watch. IT was sad to s
Re:NASA (Score:4, Funny)
We're taking this approach as of 2009 in the UK.
The new seasons will be "Cold and Wet", "Wet and Windy", "Wet" and "Wet and Dark".
Doesn't really matter how they map to the current seasons.
Parent
Well, it's been a great track record lately... (Score:5, Insightful)
Re:Well, it's been a great track record lately... (Score:5, Interesting)
I still remember the day he came into class and told us about the rovers. He had literally just gotten off the plane from JPL, and asked if there were any reporters in the room (for the school paper or otherwise). He then told us that since there wouldn't be a public announcement of the MERs for another month or so, that everything he told us was "off the record." it was so cool to learn that and all the other insider-info.
Parent
Happy to help a fellow geek (Score:5, Funny)
Should be enough to get going. No boobytraps there. I promise.
Parent
Re: (Score:3, Funny)
You sure she's not a Kiwi who lives in Melbourne? There's a lot of them here. :D
Re: (Score:3, Interesting)
Netball's like basketball, but tougher - most netball players I've known had thighs that could crack walnuts.
Good luck - and wear wrist / ear protectors if you get past first base :o)
Re:Well, it's been a great track record lately... (Score:4, Interesting)
Yes, Mars they are doing. But do you remember when the last lunar soft landing happened ?
1976, Luna-24, a successful sample return probe sent by USSR.
There is a likelyhood that the next one to land will be a Google Lunar X-Prize participant ..
Parent
Re:Well, it's been a great track record lately... (Score:5, Insightful)
To be fair here, Luna 24 returned 170.1g of regolith. NASA on the other hand landed six 14.7 tonne probes on the Moon in the late sixties to early seventies. They deployed a total of twelve autonomous intelligent versatile exploration units, traversing a total of 97km of lunar surface, and gathered some 381.7kg of samples and returned them to Earth.
To follow that spectacular accomplishment with a few petty robot landers seems... pointless.
Parent
Re:Well, it's been a great track record lately... (Score:4, Insightful)
But much cheaper.
Parent
Re: (Score:3, Funny)
Unfortunately, the Russians were unable to allocate gyros and other mechanisms for the golf-swinging arm of the robot in their design, so their funding was heavily slashed.
Re:Well, it's been a great track record lately... (Score:5, Interesting)
So you are saying that sending robots to Shackleton crater to search for water ice, or sending prototype plants to test out ISRU technologies like cooking oxygen out of lunar regolith would be rather pointless, just because a bunch of astronauts already made some footprints there ?
I am not disputing the accomplishments of Apollo, but to say that lunar robots are pointless is naive.
By the way, looking at the launch calendars, it looks like Indo-Russian joint mission Chandrayaan II might beat GLXP to the lunar surface.
Its been sad that our closest neighbour has been basically forgotten for so long, and now with Chinese, Indians and Japanese entering the lunar exploration, things are looking up.
Parent
Re: (Score:3, Insightful)
The secret to exceeding expectations is to set them very low. In this case, they built rovers that might last several years, then slapped a "90 day warranty" sticker on them.
Why heaters? (Score:5, Interesting)
So honest question for all you rocket scientists out there: Why are heaters needed? Which parts of the spacecraft (electronics?) need to be above a certain temperature to operate? Is it possible to let the lander "freeze" and then revive it, or if not what components are sensitive to this?
Rich.
Re:Why heaters? (Score:5, Informative)
So honest question for all you rocket scientists out there: Why are heaters needed? Which parts of the spacecraft (electronics?) need to be above a certain temperature to operate? Is it possible to let the lander "freeze" and then revive it, or if not what components are sensitive to this?
Rich.
One issue is that solder joints between components can break if they are cooled down too much. Batteries and capacitors can fail if liquids inside them freeze and crystalise. While I think there is a chance that the lander will come back up next summer but the likelyhood of this is pretty slim IMHO.
Parent
Re:Why heaters? (Score:5, Informative)
The heaters serve the purpose of keeping the electronics within tested survivable limits.
Parent
Re:Why heaters? (Score:4, Funny)
The heaters serve the purpose of keeping the electronics within tested survivable limits.
IANARS, I just RTFA
Parent
Re:Why heaters? (Score:4, Informative)
Parent
Re:Why heaters? (Score:4, Informative)
It's pretty cold in space....
Well that really depends on how near you are to a source of heat... in fact overheating is a problem in the solar system as it's difficult to get rid of the heat from the sun.
Parent
Re:Why heaters? (Score:5, Informative)
It's the mechanical moving parts as well as the batteries and other delicate systems. Problem is these parts are larger than the rovers that simply use hot radiation pellets of plutonium dioxide to do the heating for them.
They CAN shut it all down, park the moving parts and let it sit dormant for all winter, but when you shut a system down there is a good chance that when you fire it up in the spring that it will not fire up. Blown dust cakes into an armature hinge point and now it can no longer move.
Parent
Re: (Score:3, Informative)
Batteries are number one.
Capacitors would be number two.
Solder joints from uneven contraction.
We are talking about cold here. I mean a cold that makes Antarctica look warm.
Too bad they didn't use an RTG. The colder they get the more power they make.
Re: (Score:3, Informative)
I don't think they use oil... in the past they used WS2 (tungstendissulfide), It is a powder that sticks to metal. but hey... IANARS
When the lander dies on Mars... (Score:3, Funny)
...can we then assume that since something _died_ on Mars that there was once something _living_ on Mars?
what I do not understand. (Score:4, Insightful)
so no sunlight = no power. the lander dies.
but in the next season, assuming it has not been buried in dust it will then get power again from the solar array, so what then? surely some basic SW should be functional as the power rises over a certain point. and it does not need a huge amount of power to transmit basic telemetry like temperature, light, perhaps the odd photo in low res broadcast at low power.
with all the research and development that went into the thing, I do not see why one season should kill it.
however, I recognize I am not an expert and the people who write the articles presumably are, so what have I missed?
corrosion in the environment?
batteries that cannot survive being fully discharged?
lander cannot run on solar alone?
anyhow, kudos to NASA for lasting well beyond the tables life span in the first place.
Re:what I do not understand. (Score:5, Informative)
Parent
Re:what I do not understand. (Score:5, Interesting)
What I'd like to see is the development of cold-resistant electronics. Can we use solid capacitors and batteries for that purpose?
Then the power-draining heaters won't be needed anymore and the power can be routed to more useful instruments (or the probes can be lighter, with lower launch costs).
Parent
Re: (Score:3, Insightful)
But testing over a wider temperature range and getting it build to this spec would be expensive as hell.
On the other hand, 'expensive as hell' is not that much when compared to the cost of getting a pound of stuff from Earth to Mars - so if it allows us to use the rover twice as long, then it may be cheap enough to do, as sending a ten times more expensive rover would be much cheaper than sending two current rovers, just due to the high cost of transport.
Re:what I do not understand. (Score:5, Funny)
ok sorry i'm being a little harsh there it's been a long day. solder will crack and oils will freeze and expand busting caps etc. that's why the lander might not make it through the winter.
Parent
Re: (Score:3, Informative)
It's therefore possible to immerse parts of the anatomy in liquid nitrogen for a fairly s
Re:what I do not understand. (Score:4, Funny)
Idiot Geek. You GIVE the rose TO the coed (intact, NOT frozen). You go somewhere else and play with the liquid nitrogen.
No wonder you folks never get laid.
Parent
Re:what I do not understand. (Score:5, Informative)
Parent
Oblig. (Score:5, Funny)
and finally after the cameras fail... (Score:4, Funny)
the native martians will appear and take it into their homes for the winter and nurse it back to health...
Nuclear batteries (Score:5, Insightful)
Why the hell aren't we putting nuclear batteries on these things?
Re: (Score:3, Informative)
Re:Nuclear batteries (Score:4, Informative)
The word nuclear scares the public. More specifically I live by the cape, when they launch nuclear powered missions like New Horizons Pluto mission local schools are required to keep children indoor and close their windows. This is a precaution. If the launch vehicle blows up nuclear fallout could be spread around by winds. So generally only missions where it is required because there isn't any sun light like a mission to Pluto do they use nuclear reactors.
Parent
Re:Nuclear batteries (Score:5, Informative)
Those are not nuclear reactors, but radioisotope thermoelectric generators (RTGs). Rather than harnessing the energy from steam heated by the fission of heavy nuclei, they get the power directly from the heat of natural decay of radioactive isotopes using thermocouples. Link. [wikipedia.org]
Current nuclear reactor designs, even the compact ones used on ships and submarines, are too large and too heavy to be sent into space.
Parent
Re:Nuclear batteries (Score:5, Informative)
RTG's [wikipedia.org] and RHU's [wikipedia.org] are a massive, expensive, pain in the ass and are best avoided unless absolutely necessary.
Basically -
This may well use some kind of fluid cooling loop that circulates through radiators on the crusie stage. This now gives you added problems of a pump (which must not fail or you'll lose the mission, so add a back-up pump) and how to disconnect the coolant pipes with absolute reliability when the time comes to ditch the cruise stage and enter the Martian atmosphere. More problems, cost and weight.
Parent
Re: (Score:3, Insightful)
I'm pretty confidentent that even a catostrophic failure wouldn't create a nuclear meltdown even remotely like that. I could see the nuclear material falling to the ground and needing a cleanup crew to take care of it as a worst case, but I can't see something like this creating a new Cherynobyl (spelling probably off missing my coffee this morning) unless someone REALLY screws up.. but if your worried about that you should probably be more worried about them wanting to install new nuclear powerplants then
Re:Pyrotechnic unit? (Score:5, Informative)
Lots of space hardware uses a small pyro charge to deploy antennas and things. On a lot of microsats, the antennas are rolled up like steel tape measures, and when the pyro blows they unroll and stick out.
Parent
Re:Pyrotechnic unit? (Score:5, Interesting)
Parent