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Hopefully this problem with radiation exposure when traveling to Mars can change the way people evaluate nuclear propulsion. One could offset a lot of radiation

Hopefully this problem with radiation exposure when traveling to Mars can change the way people evaluate nuclear propulsion. One could offset a lot of radiation exposure from a nuclear power plant by getting to Mars in weeks instead of months. People traveling to Mars are not going to have a "safety first" philosophy that is dominant in the current US culture and would be able to understand and accept the trade-off. Maybe someone will start working on nuclear rockets again. I think a large number quality people would come out of the woodwork to be able to be part of such a project.

nradov 9y ago
The trouble with nuclear propulsion is not the safety of the astronauts travelling to Mars, but rather the safety of people on Earth. If you launch a large reactor from Earth then a catastrophic launch vehicle failure could cause a radiological incident. Space agencies have launched RTGs before, but those are much smaller and more durable than the real reactors that would be needed to drive a useful propulsion system. Maybe someday we'll be able to mine fissionable materials from asteroids and construct nuclear rockets in deep space with no risk to Earth. But that technology is firmly in the realm of science fiction today.
- njarboe 9y ago
  If one gives this problem a bit of thought I think it is really political problem, not a safety issue. First, nuclear fuel is just pieces of metal or ceramic. If it blows up on launch these won't explode in a nuclear chain reaction like what happens in a nuclear weapon. They will just scatter and fall into the sea. They have not been activated yet so they have very low radioactivity at that point. Brand new nuclear fuel is basically harmless. The worry with nueclear fuel is after it is used it becomes very radioactive. And, even if the fuel was a problem, reactors are going to be designed to be refueled. One could send up the reactor and fuel on different launches with the fuel sent in packaging the would survive any explosion (although the fuel itself already would) RTGs are actually more of a radiological hazard, as the fuel for those are necessarily very radioactive. In the end I do agree with your position that the safety of the people on Earth are likely to be a problem because safety is a feeling, not some well defined risk factor. Without some large generational educational project (or maybe change the name?), most people will think that nuclear power can never be safe, even when driving their gasoline powered car on a two lane road to work.

nradov 9y ago

The trouble with nuclear propulsion is not the safety of the astronauts travelling to Mars, but rather the safety of people on Earth. If you launch a large reactor from Earth then a catastrophic launch vehicle failure could cause a radiological incident. Space agencies have launched RTGs before, but those are much smaller and more durable than the real reactors that would be needed to drive a useful propulsion system. Maybe someday we'll be able to mine fissionable materials from asteroids and construct nuclear rockets in deep space with no risk to Earth. But that technology is firmly in the realm of science fiction today.

njarboe 9y ago
If one gives this problem a bit of thought I think it is really political problem, not a safety issue. First, nuclear fuel is just pieces of metal or ceramic. If it blows up on launch these won't explode in a nuclear chain reaction like what happens in a nuclear weapon. They will just scatter and fall into the sea. They have not been activated yet so they have very low radioactivity at that point. Brand new nuclear fuel is basically harmless. The worry with nueclear fuel is after it is used it becomes very radioactive. And, even if the fuel was a problem, reactors are going to be designed to be refueled. One could send up the reactor and fuel on different launches with the fuel sent in packaging the would survive any explosion (although the fuel itself already would) RTGs are actually more of a radiological hazard, as the fuel for those are necessarily very radioactive. In the end I do agree with your position that the safety of the people on Earth are likely to be a problem because safety is a feeling, not some well defined risk factor. Without some large generational educational project (or maybe change the name?), most people will think that nuclear power can never be safe, even when driving their gasoline powered car on a two lane road to work.