Chinese astronauts make rocket fuel and oxygen in space

This won't enable perpetual space travel in case anyone thought so.

Rockets need to eject particles to generate force. And to eject 1 kg of fuel, its photo synthesis system has to lose 1 km of mass in one way or another.

The solution is to find a way to generate thrust without rocket fuel ejection.

Can we "swim" through space? Collect particles from space, add energy, expell them backwards to generate a net thrust.