View Full Version : propulsion

2006-Oct-17, 06:34 PM
I want to know why NASA has not yet built a fission reactor propulsion system,?
Could it be done,?
Is it just the cost,?
How fast would it go,?

2006-Oct-17, 06:55 PM
They have built several, but they haven't left the ground.
The now shelved Prometheus project was one of these.

It was shelved for cost. It was going to be used for providing electric power to drive an ion engine, so the acceleration would have been slow, but the eventual speed could have been pretty high (up to about 100 km/sec).

Bearded One
2006-Oct-17, 07:10 PM
Cost and environmental concerns keep getting in the way. A lot of people have issues with launching nuclear reactors into space.

2006-Oct-17, 07:26 PM
Politics is the biggest problem. A nerva type nuclear-thermal rocket is not politically feasable for surface to orbit work, never mind the radiation. For in space work, ion and plasma thrusters will give a higher ISP than a nuclear thermal system. For the high end plans for spacecraft, they will require in space reactors, and NASA is trying to put off the nuclear firestorm for as long as possible