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Are Nuclear Powered Mars Rovers a Good Idea?
meatybeans writes "NASA officials are meeting today, with concerned residents around Cape Canaveral, regarding the power system for the upcoming Mars Science Lab mission. MSL is going to be like our current rovers on steroids. The plans call for a larger, heavier rover with a lot more juice for gadgets. This meeting however brings to light the issue of the power system for the MSL. The Mars Science Lab originally called for a nuclear power source, much like the Cassini and New Horizon missions use. Some vocal opposition to this has been voiced in the past. As a result, NASA has backup plans to employ solar power and small amounts of RTG's ? if arguments against straight nuclear for MSL win out. As with most, things 'NIMBY' ? seems to be in full effect when it comes RTG's. Does the recent success of the rovers show us that RTG's are not needed for Mars exploration? Are 1:420 odds of an accident that bad? Finally, are the hearings that are taking place between NASA and the public really just a formality in the name of public relations?"
Of course they ar*KABLAM!*
Of course it's a good idea! Ship all the evil nukuler stuff to Mars and the terrrrrists can't get their hands on it!
For now.
Why don't they just use batteries? I hear Sony has a surplus.
Meta will eat itself
Yes, of course they're a good idea. People should get over their irrational fear of decaying nuclei.
As I pointed out in the Victoria Crater story, there are places a solar-powered rover can't really explore effectively, or for very long. You can't just land the current MER rovers "anywhere" on Mars and expect them to work. An RTG-powered rover will work longer and better than a MER rover, assuming all other things are equal (not breakdowns elsewhere). Suppose instead Spirit and Opportunity had been RTG-powered... would we now be saying, "Hey, these RTGs work great, so why bother with solar probes anymore?"
But the real answer to your quest is that RTGs aren't dangerous, so the entire premise of the question is flawed. A launch failure isn't going to make Florida a radioactive wasteland. We've launched dozens of RTGs in past missions. The last big "outcry" was over the Cassini mission, and NASA made the correct decision and launched anyway. Hopefully they'll make the correct decision again and use RTGs for the future rovers like MSL. Bottom line: it's not any more risky to launch an RTG powered probe than a solar powered one, so you use RTG power for the missions that need it and solar power for the missions that need it.
Bruce
I'm sorry but the mission success rate is pretty damn low. I mean we have been doing very basic stuff and failing horribly. No way do I think the odds are very good for a successful nuclear powered mission. Most engineers suck and their project management sucks even more, it's as simple as that.
The problem with a failed launch, might create the need for recovery, which may be a problem if reactive ingredients, were to land on hostile territory.
I think assembly in space is the safest bet tho.
Even if the launch system fails, the question should be, what happens to the fissile material? And the answer? Absolutely nothing. It is in a container that is meant to withstand that. All in all, it would still be in one piece. The advantage of nukes is that a great deal more science can go on for a LONG time (and at a lighter weight). Considering that there is no real risk, we really should use them.
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I think it's a great idea. The Russian space agency had plans for a nuclear power "Mars Train" in the 60s. It was manned as well. Mars train.
In a cost/benefit analysis the nuke option makes sense. If you can get a larger rover that can move faster it opens up many new vista. I mean, I love the current Rovers for lasting so long but they move slowly and are too small to get past many geological barriers. A larger rover could carry more equipment and move farther and faster.
No-one likes the idea of the power source rupturing but on a planetwide basis it's not a major issue. Mars has probably received more radioactive material from comets et al than would be found in the battery and as we're not going to get there for another twenty years at best harm to humans isn't an issue. The worst result for us would be the plethora of B-movies about the radioactivity causing hyper-evolution that turns algae into ravening Martian monsters that look suspiciously CGIed.
But maybe the whole strategy is wrong. Instead of a few big rovers make lots of little ones. You get a better sampling of a variety of areas on the planet for your budget and it matters less if a few don't survive the trip.
Would it result in more radiation than an "open air" nuclear explosion test? What does it compare to?
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Are nuclear powered rovers a *bad* idea?
In the past? Is that like in the '60s?
What is the basis for the argument?
If the people coming up with these odds are the same ones flying the ship, I would be a little nervous... "DUDE Where's Our Rover?????"
# cat
Damn, my RAM is full of llamas.
the correct quesion should be, 'what's wrong with continuing to build solar rovers that we need a nuclear one? So far, the solar ones haven't stopped running, so I'd say that solar is a home run.
stuff |
Their power was expected to last 90 days, it's lasted over three years. /other/ parts that keep going bad.
It's the
More power might be able to mean more spare parts, though..
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My question is, why are these people afraid of a *single* launch malfunctioning and scattering waste in their area, when the US Air Force still has planes launched 8all the time* from *all over the country* that have strategic nuc lear weapons on them? They are never fired, for sure, but any plane accident could cause just as much damage as an accident with one of these NASA launches. In fact the weapons likely have even more dangerous material in them, for obvious reasons.
I'm quite sure other launch facilities are quite as capable of getting the payload off the ground. I'm quite sure Russia wouldn't mind getting that baby into the air, without asking what's on board.
And cheaper too.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
They're a brilliant idea.
Seriously, educate yourself of RTGs if you're worried about launch safety.
Secondly, as others have pointed out, they're an excellent, long-lasting, power source.
A thought just struck me. For much more additional cost, you could make the robots bigger and heavier with much bigger solar panels. They could have batteries big enough to hold several days' charge.
I'll go with the RTGs, which last decades and result in a smaller, more reliable, and more manoeverable vehicle.
Anyway, I'm sure the Martians are more radiation-hardened than we are, what with that thin atmosphere.
Stick Men
Scores, if not hundreds, of RTGs have been used in space exploration, going back to the '60s. There have only ever been three - iirc - incidents where the RTG's have been breached, resulting in detectable radioactive release.
Despite always having been controversial, RTGs have been proven safe.
Even if you run the space probe from solar cells, you cannot have analytical instruments such as Alpha particle X-ray spectrometers and Mossbauer spectrometers without radioactive sources.
I guess it depends on whether you're going to launch 420 of them, and what an "accident" means :-)
A chunk of metal falling into the sea probably isn't too worrying, but a nuclear device exploding and showering particles over a city, mmm, slightly more problematic...
Firstly, it's a matter of cost/benefit - will a nuclear power source on board the rovers be that much more effective? Would it add weight? Would the benefits of a higher speed (I assume) be worth the risk of hitting a rock and denting an axle? This is something for the scientists to state their opinion of, I suspect they do think it would be a large improvement or they wouldn't have asked for it
Secondly, and more importantly - that container need to withstand falling into the sun. Regardless of whether the dust from an explosion would be indistinguishable from background radiation and no more toxic than eating earth, you know conspiracy theorists would seize on it globally with calls of 'global radiation poisoning of Mother Earth' - and lots of people would listen with at least one ear. Times the next hundred years.
Suppose ordinary reactors are used (not these RTGs). What would be the problem? I guess they aren't active during launch or even transit, so what could happen is the breakdown on the surface of Mars. A small one at that. Isn't that enough safety distance? ;-) Even if we go there soon, does it really matter?
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*sigh* People misunderstand Nuclear devices... Nuclear Power Systems are 100% safe. Well, I guess maybe I should say that Canadian made CANDU Nuclear Reactors are 100% safe. See, uranium needs something to react in, a cooling substance if you will. In the CANDU rector H2O (except that it's an isotope of hydrogen), Heavy Water (Deuterium) is used. I know it seems a bit Star Trek, but that's what it's called. The Heavy Water has to be almost 100% pure for the reactor to function. If NASA uses CANDU technology, there will be no problems. If the reactor breaks, the Heavy Water will be contaminated and the reaction will cease. Another thing thing, reactors do not cause Nuclear Winters. A Nuclear Meltdown does NOT mean explosion. Nuclear Missiles are COMPLETELY different than Nuclear Reactors. GOOGLE IT! CANDU Reactor
Are marsians complaining about?! What then.
I have no problem with RTG's. It has been conclusively shown that RTG's are safe even when launch fails. What hasn't been shown is what happens when a RTG impacts Earth at 10km/s or more, as would be the case in a gravity assist gone wrong.
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I mean, according to the article, lots of other RTGs have been launched without complaint, so it's not the launch site that's the problem.
NIMBY must be protecting the people with houses on Mars, that's the only logical explination (`sarcasmd --on` and we know NIMBY is logical, `sarcasmd --off`).
So, where do I get my Martian house!?
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Because it's radio-ACTIVE ??? It's not fissile means its nuclei would not break apart, but it does not mean that its nuclei would not decay (like emit _one_ neutron and some photons per nucleus in its lifetime). That is what a RTG taps into: get those photons (heat) and generate kinetic energy for some electrons (electricity). But now, you don't want some Joe Sixpack's pile of junk car leeking neutrons because they are NOT GOOD for your health.
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The reason NASA launches rockets from Florida is because rockets launched near the equator travelling east gain an ENORMOUS speed boost from the Earth's rotation. Also, if the rocket breaks up, it will break up over water. The Soviet Union is a tad farther north than Florida, so the rocket would require more fuel. Rockets have traditionally been a very NIH enterprise, so countries are relunctant to depend on others for their orbital needs.
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'what's wrong with continuing to build solar rovers that we need a nuclear one?
Well, for one, this new rover is going to be much larger than the previous ones. More equipment = more power, and I imagine a nuclear fuel source would have a much higher energy/weight ratio than solar panels.
A good idea? Are they even necessary?! As we've been so excitingly reminded, today, two solar-powered rovers are at almost %1000 of their predicted operational lifetime, an utter engineering miracle. But the fact that this is the most weight we can send up without blowing earths' budget, Contact-style, suggests that there's no way we can put enough machinery up there to require that kind of energy.
This meeting however brings to light the issue of the power system for the MSL. The Mars Science Lab originally called for a nuclear power source, much like the Cassini and New Horizon missions use. Some vocal opposition to this has been voiced in the past.
You know I'm sick and tired of driving around in oil powered vehicles. We should have nuke powered vehicles that only need filling once when manufactured and they last for the life of the vehicle. We'll never get it though because the anti-nuke lobby would be absolutely horrified at the thought of any nuke powered vehicle accident. The oil energy companies really shouldn't have to worry because we still need vast quantities of oil for our industrial society. In some sense, we've been "wasting" oil by burning to get around. There are tons of products that we make out of oil and that's not going to change if we switch from an oil fueled vehicles.
Both is a possibility, solar and the RTG. That's the best idea, redundant power supplies, a hybrid system. Much better to have more than adequate power it seems. Both methods are continually undergoing improvements as well,and after all it was the space program that really pushed the development of solar PV and we have had significant breakthroughs there even since the mars rovers currently working were launched.
Well if the energizer bunny is anything to go by, then we should have the rovers powered by bunnies :)
Jumpstart the tartan drive.
First, keep in mind that RTGs are very expensive, very tricky to work with, very inefficient, and if NASA can avoid playing with them, it does, because that means more money for other programs.
Most Mars vehicles use small units that contain plutonium and function as heaters during the very cold night. This reduces the thermal stress between day and night and allows the vehicle to survive far longer than it would without them. It is only very recently that vehicles have been designed without this.
By having RTGs, both the power and the thermal stress issues are minimized. Viking lasted for many years and the ALSAP probes on the moon did as well (and would have lasted longer if it weren't for the Carter administration shutting down space probes left and right).
We can't count on duststorms clearing the panels on future rovers as they have with our equatorial probes this time around. When you design something for a 90 day life and it lasts eight plus times longer, great. If you design a probe to last for years and it doesn't, that's a serious issue because of the increased cost of the larger rover.
I would like to point out that the "outcry" over Cassini really wasn't a case of NIMBY. I live in south Florida not too far from the Cape. I have no problem with RTGs and frankly I know of only a single person that was worried about. She also bought a lot of wheat for and heirloom seeds back in 1999 for the end of the world. I spent a long time calming her down and explaining RTGs to her. Even she now doesn't have a problem with them.
Frankly it is a few nut jobs that make good news stories. There are several hundred thousand people that live around the cape. The protests where a few dozen and many of them traveled a long way for their 20 minutes of Warhol.
Build them an launch them I will be be glad to watch the launch from by backyard with a cool drink in my hand, smile on my face, and hope in my heart.
Mindless fear? NOT IN MY BACK YARD.
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NASA really needs to launch nuclear-powered missions from places where these whackos can't throw their clogs into the machinery of progress. In secret. Forget secret prisons, we need secret launch facilities.
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The recently landed probe MarsLife that should have given us the definitive answer on whether there is life on Mars, has indeed given us that answer.
There used to be life on Mars, pretty much up until the moment out Mars Science Lab crashlanded.
Coz eternity my friend, is a long *ing time.
Please don't paint all of us "locals" with the same brush. It's going to be launched "in my back yard", and I don't have a problem with it. It's traditionally what we do here (launch rockets), and more than adequate safety margins are in place as many here have detailed.
Now, driving on I-95 to go see the launch... That worries me a bit more, risk-wise, but I'll get over it...
As the subject states, there is no need to increase power reserves of mars rovers. If you had even spend five minutes reading about the current state of the rovers you'd see that clearly other components fail before solar power fails. Also remember that nuclear type batteries were used for long missions which stray very far from solar energy. It is still the case that nuclear power would only be good when a device would be out of line of sight from the sun for a long period, or far enough that it cannot convert enough solar energy.
This is a dumb question.
I'm so anti-NIMBY on RTGs that I'd like 3 buried in my foundation for my house.
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Are they safe? Yes. Shutup. We're launching.
If you long haired hippy freaks don't like it, tough.
-Styopa
Everyone needs to remove their tinfoil hats and get comfortable with mankind's best known source of power. The irrational fear of nuclear power leaves us dependent on fossil fuels and a whole slew of weaker, more expensive, less available power sources. I honestly wish I could use an RTG to power my car. I'd put one in my laptop, if they could make it small enough. I want one in my iPod. Nuclear power is safe, clean (relatively), and efficient.
NASA has launched several missions on RTG power. Some of those launches have failed. Florida still looks safe to me.
Get over Three Mile Island and Chernobyl, and start embracing science.
It's too bad that SONY's recall program doesn't include free return postage...
Sometimes boldness is in fashion. Sometimes only the brave will be bold.
I would just like to point out that nuclear power sources are already there. The Mars Rovers, Spirit, and Opportunity contain radio-isotope heaters to stave off the chilly days and nights of the red planet. Granted, this is a much smaller power source (and the only energy being recovered is heat), but I would like to point out that sending nuclear power sources out is nothing new.
r e_environments.html
http://marsrovers.jpl.nasa.gov/technology/is_seve
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... it's pronounced [n(j)ukj.l()]
The existing power source is still working - the solar panels are working better than
...
expected and havn't given any real problems.
What's failing are the mechanical bit's and pieces.
So - what will putting a bigger power source do ?, wear out the wheels faster.
Going nuclear is solving a problem the rovers don't have.
Duh
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How about this: Put a decent set of solar panels on the rover. Then whatever remaining power is still needed, use nukies to make up for it. The nukie would then be smaller because solar takes up most the slack. True, solar panels can't work at night and on some slopes, but a hybrid may allow some work in such dark conditions, just not full-out. For example, maybe on only one instrument at a time could be active instead of many during the dark.
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