Re:Alan Bean, 4th Person to Walk on the Moon, Dies at 86
by gpm on Sunday May 27, 2018 @09:14AM
(#17166764)
There are various ways to cheat the rocket equation that weren't possible during Apollo because of our level of technology, and to some extent the constraints of a mission where a substantial portion of the energy is consumed getting to LEO. I don't want to suggest I know how to build an interplanetary spaceship accelerator, but here are some common basic ideas
- Accelerate the ship be pointing lasers (or something that accelerates matter) at it from the launch point. Now one doesn't need to carry fuel and the rocket equation no longer applies.
- Use some form of ion engine where we accelerate particles to very high speed relative to chemical rockets. This makes the rocket equation very tame since so little of the mass (relatively speaking) is in propellant.
- Combine the above ion engine with some form of "ramjet" that takes hydrogen we collide with and turns it into fuel. This makes the rocket equation irrelevant since we don't carry our fuel (to the extent that we can get our fuel via the ramjet anyways).
Also as laumars says the 0.1% of annual energy usage was just a point of comparison because terwatts is such a foreign unit to most of us (including me) that it doesn't mean anything by itself.
- Accelerate the ship be pointing lasers (or something that accelerates matter) at it from the launch point. Now one doesn't need to carry fuel and the rocket equation no longer applies.
- Use some form of ion engine where we accelerate particles to very high speed relative to chemical rockets. This makes the rocket equation very tame since so little of the mass (relatively speaking) is in propellant.
- Combine the above ion engine with some form of "ramjet" that takes hydrogen we collide with and turns it into fuel. This makes the rocket equation irrelevant since we don't carry our fuel (to the extent that we can get our fuel via the ramjet anyways).
Also as laumars says the 0.1% of annual energy usage was just a point of comparison because terwatts is such a foreign unit to most of us (including me) that it doesn't mean anything by itself.