I’ll be the actually guy because it’s pretty cool but there’s no fuel needed for the return since the moon’s gravity did the job to turn around Orion and with inertia plus Earth gravity Orion will essentially fall back to Earth.
The whole thing is actually quite similar to throwing a ball in the air, it goes up slowing down until it turns around and comes back to you. On a different scale but the idea is quite similar so the only energy truly needed is the initial push (plus a few trajectory adjustement).
By the time you enter an orbit around the Moon (actually once you start a capture burn), you will need fuel to return. The free return is only a contingency for something going wrong on the first part of the mission. Also I am a bit foggy on whether a safe reentry is possible from a free return trajectory without any mid course correction burn on the way back. (Possibly that can be done with RCS only, though, which you need to put the spacecraft in the right attitude to survive reentry anyway)
I’ll be the actually guy because it’s pretty cool but there’s no fuel needed for the return since the moon’s gravity did the job to turn around Orion and with inertia plus Earth gravity Orion will essentially fall back to Earth.
The whole thing is actually quite similar to throwing a ball in the air, it goes up slowing down until it turns around and comes back to you. On a different scale but the idea is quite similar so the only energy truly needed is the initial push (plus a few trajectory adjustement).
By the time you enter an orbit around the Moon (actually once you start a capture burn), you will need fuel to return. The free return is only a contingency for something going wrong on the first part of the mission. Also I am a bit foggy on whether a safe reentry is possible from a free return trajectory without any mid course correction burn on the way back. (Possibly that can be done with RCS only, though, which you need to put the spacecraft in the right attitude to survive reentry anyway)