As some of you may be familiar with the rocket equation and nuclear-powered submarines, for instance, I am interested in hearing your views on the possibility of using nuclear thermal propulsion instead of chemical propulsion. The incoming head of NASA is a big proponent of nuclear space, so there may be some activity in the area in the coming years.
The specific impulse (fuel efficiency) of a solid core nuclear engine with LH2 as a propellant is expected to be some 800-900 seconds. Even though this is only twice the specific impulse of LH2/LOX, which is used today in various rockets, a solid nuclear engine would make it "easy" to have a reusable rocket with only a single stage (or at least a stage and half) and would increase a lot of the safety margins that drive the extreme expense of spaceflight.
We have some experience with nuke subs, and that has been very positive to my mind, even though I don't know too much about nuke subs. We also have some experience with nuclear engines destined for space uses. The Kiwi solid core reactors and NRX engines were built and tested. 1,100 MW generated. The Phoebus engine generated 4,000 MW (i.e., the most powerful reactor ever built). A follow on viewgraph in the NERVA program was an engine of about 1,000 MW to be mated with a Saturn V upper stage.
So what say you? Is this just a huge boondoggle to the aerospace contractors and inherently unsafe otherwise, or is there substance here?
The specific impulse (fuel efficiency) of a solid core nuclear engine with LH2 as a propellant is expected to be some 800-900 seconds. Even though this is only twice the specific impulse of LH2/LOX, which is used today in various rockets, a solid nuclear engine would make it "easy" to have a reusable rocket with only a single stage (or at least a stage and half) and would increase a lot of the safety margins that drive the extreme expense of spaceflight.
We have some experience with nuke subs, and that has been very positive to my mind, even though I don't know too much about nuke subs. We also have some experience with nuclear engines destined for space uses. The Kiwi solid core reactors and NRX engines were built and tested. 1,100 MW generated. The Phoebus engine generated 4,000 MW (i.e., the most powerful reactor ever built). A follow on viewgraph in the NERVA program was an engine of about 1,000 MW to be mated with a Saturn V upper stage.
So what say you? Is this just a huge boondoggle to the aerospace contractors and inherently unsafe otherwise, or is there substance here?
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