Scott Manley has a fantastic video explaining all of this: https://www.youtube.com/watch?v=4QXZ2RzN_Oo https://www.youtube.com/watch?v=4QXZ2RzN_Oo In terms of

Scott Manley has a fantastic video explaining all of this: https://www.youtube.com/watch?v=4QXZ2RzN_Oo https://www.youtube.com/watch?v=4QXZ2RzN_Oo In terms of efficiency, it's worth mentioning that even tiny gains have big impacts because of the rocket equation. Having a 1% boost the entire time the rocket is running can have an enormous impact in the overall velocity, or reduce the overall amount of fuel needed for the same targets.