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I wonder why there aren't any realistic plans for using nuclear propulsion. Chemical rockets simply produce too low thrust. Using nuclear pulse/fission fragment

I wonder why there aren't any realistic plans for using nuclear propulsion. Chemical rockets simply produce too low thrust. Using nuclear pulse/fission fragment rockets the solar system can be explored in a matter of months, rather than the years/decades that we're currently forced to endure. Project Orion was supposed to be feasible with 60s technology. Why aren't we trying to make similar technologies work?

nickff 10y ago
The main problems seem to be risk aversion and environmental groups. There will always be some risk to sending fissionable material on a very large chemical explosive (rocket); given our society's current risk aversion, it seems like a 'hard sell'. Environmental groups have been protesting every use of radioactive material in space for the last ~20 years, and seem likely to continue to do so; in the current political climate, nobody has the will to ignore them.
- justin66 10y ago
  It's incorrect to characterize the opposition as coming only from "environmental groups," as if the opposition those groups embody isn't representative of a public that largely defecates itself whenever the word "nuclear" is used in a sentence. Ignoring the groups, or the people, isn't an option. Developing safer nuclear options and educating the public as to why they're safer might work, although educating the public... yeah.
gene-h 10y ago
For one, nuclear pulse rockets violate several international treaties. Fission fragment rockets, while the performance is impressive on paper, have yet to be demonstrated in the lab. Nuclear thermal propulsion has been demonstrated on Earth[0] and Nuclear electric propulsion has been flight proven[1]. NASA had a serious effort to develop and flight prove a high power(200 KWe) nuclear reactor[2]. This would have been used to power the Jupiter Icy Moons Orbiter[3] which would have explored Europa, Ganymeade, Callisto, and Io if things were favorable. The reactor enabled high power electric propulsion, high bandwidth communication(10Mbit/s), and even a full scale ice penetrating radar. This much power is hard to come by as far out as Jupiter. The entire effort lasted about two years before it got canceled because NASA needed to free up money for the (now canceled) Constellation Program. The thing I would like to emphasize here is that this was a serious effort with money on the table and a mission in place. The nuclear propulsion work NASA is currently working on is either a concept study, that is just investigating whether an idea can work at all, or not very well funded. The issue is getting the funding to develop the hardware and actually following through [0]https://en.wikipedia.org/wiki/NERVA https://en.wikipedia.org/wiki/NERVA [1]https://en.wikipedia.org/wiki/Kosmos_1867 https://en.wikipedia.org/wiki/Kosmos_1867 [2]https://en.wikipedia.org/wiki/Project_Prometheus https://en.wikipedia.org/wiki/Project_Prometheus [3]https://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Orbiter https://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Orbiter
- maverick_iceman 10y ago
  I'm aware of the fact that nuclear pulse rockets will violate atmospheric test ban treaties. However I think if some major countries were serious about it then an exception for pulse propulsion could have been added to those treaties. (Yes, I understand the potential for abuse but in my mind the upsides and an effective monitoring system far outweigh the risks.)
sien 10y ago
Perhaps people are waiting for a space elevator or settlements in space that could build nuclear rockets. Project Daedalus ( https://en.wikipedia.org/wiki/Project_Daedalus https://en.wikipedia.org/wiki/Project_Daedalus) in the 1970s was the last time people looked seriously at theoretical proposals for nuclear powered interstellar flight.

nickff 10y ago

The main problems seem to be risk aversion and environmental groups. There will always be some risk to sending fissionable material on a very large chemical explosive (rocket); given our society's current risk aversion, it seems like a 'hard sell'. Environmental groups have been protesting every use of radioactive material in space for the last ~20 years, and seem likely to continue to do so; in the current political climate, nobody has the will to ignore them.

justin66 10y ago
It's incorrect to characterize the opposition as coming only from "environmental groups," as if the opposition those groups embody isn't representative of a public that largely defecates itself whenever the word "nuclear" is used in a sentence. Ignoring the groups, or the people, isn't an option. Developing safer nuclear options and educating the public as to why they're safer might work, although educating the public... yeah.

gene-h 10y ago

For one, nuclear pulse rockets violate several international treaties. Fission fragment rockets, while the performance is impressive on paper, have yet to be demonstrated in the lab. Nuclear thermal propulsion has been demonstrated on Earth[0] and Nuclear electric propulsion has been flight proven[1]. NASA had a serious effort to develop and flight prove a high power(200 KWe) nuclear reactor[2]. This would have been used to power the Jupiter Icy Moons Orbiter[3] which would have explored Europa, Ganymeade, Callisto, and Io if things were favorable. The reactor enabled high power electric propulsion, high bandwidth communication(10Mbit/s), and even a full scale ice penetrating radar. This much power is hard to come by as far out as Jupiter. The entire effort lasted about two years before it got canceled because NASA needed to free up money for the (now canceled) Constellation Program. The thing I would like to emphasize here is that this was a serious effort with money on the table and a mission in place. The nuclear propulsion work NASA is currently working on is either a concept study, that is just investigating whether an idea can work at all, or not very well funded. The issue is getting the funding to develop the hardware and actually following through [0]https://en.wikipedia.org/wiki/NERVA https://en.wikipedia.org/wiki/NERVA [1]https://en.wikipedia.org/wiki/Kosmos_1867 https://en.wikipedia.org/wiki/Kosmos_1867 [2]https://en.wikipedia.org/wiki/Project_Prometheus https://en.wikipedia.org/wiki/Project_Prometheus [3]https://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Orbiter https://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Orbiter

maverick_iceman 10y ago
I'm aware of the fact that nuclear pulse rockets will violate atmospheric test ban treaties. However I think if some major countries were serious about it then an exception for pulse propulsion could have been added to those treaties. (Yes, I understand the potential for abuse but in my mind the upsides and an effective monitoring system far outweigh the risks.)

sien 10y ago

Perhaps people are waiting for a space elevator or settlements in space that could build nuclear rockets. Project Daedalus ( https://en.wikipedia.org/wiki/Project_Daedalus https://en.wikipedia.org/wiki/Project_Daedalus) in the 1970s was the last time people looked seriously at theoretical proposals for nuclear powered interstellar flight.