Fission fragment rocket engines are also (theoretically) extremely efficient.. using the particles that come out of the reaction directly as a high-velocity exhaust stream.
Practical for many missions, just not for sending humans in person to other planets. For example, consider a mission to deliver a telescope out past 550AU so that it can use the whole sun as a gravitational lens. That’s more than 11× further than Pluto, but a fission fragment drive could get the telescope out there in about the amount of time it took New Horizons to fly past Pluto.
Fission fragment rocket engines are also (theoretically) extremely efficient.. using the particles that come out of the reaction directly as a high-velocity exhaust stream.
FFR have super high ISP but microscopic thrust. Not exactly practical.
Practical for many missions, just not for sending humans in person to other planets. For example, consider a mission to deliver a telescope out past 550AU so that it can use the whole sun as a gravitational lens. That’s more than 11× further than Pluto, but a fission fragment drive could get the telescope out there in about the amount of time it took New Horizons to fly past Pluto.
For that particular mission I’d be curious to compare to an ion drive architecture.
Don't ion drives consume comparitively a lot of xenon to work?
Yes, they have substantially lower specific impulse than fission fragment.
If you like Orion check out Project Pluto (they even built some some test bench engines)
did they ever figure out how to brake? Spin the ship 180 degrees and bomb the front?
Couldn't you just turn and orbit ?
… without irradiating yourself?