> while this can only be useful where you still have atmosphere and oxygen
The planned SABRE engine can act as a rocket as well closing the intake and using stored liquid oxygen so it would be capable of operating without an atmosphere and oxygen and landing on Mars.
Can it take off from Mars? In another HN thread a month ago, we discussed how Mars' atmosphere is so thin that a Cessna would need 747 wings and near Mach 1 velocity to take off.
The planned SABRE engine can act as a rocket as well closing the intake and using stored liquid oxygen so it would be capable of operating without an atmosphere and oxygen and landing on Mars.