Originally Posted by rickair7777

I think it needs to throttle actually, a hypersonic vehicle cannot be stealthy due to the immense thermal signature. I suspect you would want such a weapon to be able to cruise at a cool subsonic speed to get in close before sprinting to the target. Easy to throttle a reactor core (long as you don't need it to go to zero after a high power run!), the harder part would be designing the engine to deal with fluid dynamics at different flight speeds.




I think the public will accept nuclear spacecraft engines for deep space missions (we already use RTGs on some long-range spacecraft), you just need to mitigate the risk during launch to orbit. Probably have to package the thing to survive launch vehicle failure or unplanned re-entry (could ditch the heavy packaging prior to departing earth orbit). The engine would only actually be operated when leaving earth orbit and enroute, not in the atmosphere. If politically necessary, you could depart orbit on a conventional engine and the use the nuke in deep space.

I actually think this sort of nuclear engine offers the best path manned to mars. There are many technical and medical challenges to long deep space missions... reliability of flight hardware, temporary and permanent physiological degradation, cosmic/solar radiation exposure (at some point it would be essentially a guaranteed premature death sentence for the crew). A nuclear engine could cut mission transit time dramatically.

I also think instead of hemming and hawing about the affects of zero-G, they just need to accept the fact that the ship will need to be large and heavy enough to do centrifugal spin for gravity. Yes it will cost more but it could also be re-used many times (deep space or as a space station) if modular so that you can replace upgrade/components while retaining the main structure.

I have ethical reservations about sending folks on a mission that's going to destroy their health and probably kill them after they get home.




Nope, rooskies don't care. The US could build similar systems if necessary, since it would be a deterrent/doomsday weapon, the risk associated with the engine would be largely irrelevant. Although we might have to plan launch from ships/subs/aircraft, to avoid flying an operating nuclear engine over our people.