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?"

Comments

Re:They'll be perfectly fine

[Detritus]

Pu-238 is not fissile, and an RTG (radioisotope thermoelectric generator) is not a nuclear reactor, it uses the decay heat of the radioisotope to produce electricity.

Re:Result of accident?

[Ironsides]

Would it result in more radiation than an "open air" nuclear explosion test? What does it compare to?

A Radioisotope Thermal Generator (RTG) basically using nonfisile radioactive material as a heat source to create electricity. This is what has powered the two Voyager probes for the past 30 years. The amount of readiation released is effectively zero. An open air nuclear explosion releases several kilograms worth of fisile material into the atmosphere.

Oh, and as to the dangers of RTGs in case of a launch accident. We've actually launched radioactive material on a rocket where the rocket exploded partway into the flight. The nuclear material was recovered inside it's intact casing and reused on a later mission.

There is zero danger involved here.

Re:Result of accident?

[Ironsides]

Great. What are the arguments against the use of a RTG then? If there isn't any "real" damage aven locally why does it seem to such a big issue?

As the other guy said, an irrational fear of nuclear. I remember hearing that during one of the nuclear launches in the 70's, there were people protesting saying that NASA was going to kill them all by launching a nuclear powered Satelite/Probe (I can't remeber which). They protested at the launch holding up there babies holding signs "You're going to kill me." Launch went off without a hitch.

Nuclear power and weapons detonation has released far less radiation than Coal and Fossil fuels in the past 60 years (Coal contains small ammounts of Uranium). If anything, they should be protesting Coal, not nuclear.

Re:RTGs are not dangerous

[AKAImBatman]

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.

Don't forget that we've blown up a few of them, too. The original RTGs were designed to be burned up in the atmosphere. (Russia even burned one up over Canada.) So far, there are no nuclear wastelands because of it. NASA quickly figured out, however, that burning up expensive nuclear fuel in the atmosphere was probably not the best idea. So they started cladding the fuel in tough containers designed to withstand a launch failure.

Those containers have been proven twice. Once on the Nimbus launch vehicle (which was destroyed by the range officer) and the other was the emergency landing of Apollo 13. The Nimbus RTG was recovered from the sea bed, washed off and resused. The Apollo 13 unit fell in the Troga Trench and has been sitting there unpenetrated.