3 ms·
Would it be possible for the numbers to be a bit more difficult to work with so maybe we could go to low earth orbit, but never be able to make it to the moon?
by TheSpiceIsLife 7y ago
Would it be possible for the numbers to be a bit more difficult to work with so maybe we could go to low earth orbit, but never be able to make it to the moon?
- JshWright 7y agoIf you can make it to orbit, you can make it anywhere (it just may take multiple launches to assemble/fuel the spacecraft going elsewhere).
- fireattack 7y agoWait, really? So what's the deal of first and second cosmic velocity?
- cyphar 7y agoI guess the idea is that if you can make it to orbit (even if you waste all of your fuel), then you could in principle refuel in-orbit (by getting another unmanned rocket with just fuel into orbit) and thus escape the orbit. But yes, you still require more energy (exactly sqrt(2) times as much) to "escape" Earth's gravity entirely than to orbit it with a circular orbit.
- derekp7 7y agoOnce you are in orbit, anything else is possible. Because if you can get something small to orbit, you can get a lot of small things (such as additional fuel) to orbit, to reach escape velocity. That is because once in orbit you no longer have a need to reach the next velocity stage as rapidly as possible, which is why ion engines are so efficient but can only be used after LEO.
- jccooper 7y agoMaking orbit is a single hard step; raising orbit, which is all that making it to the moon requires, can be done more gradually (with low-thrust/high-efficiency engines, on-orbit resupply, etc). So if you can get off the planet you can get anywhere... but that doesn't mean cost-effectively. If your planet is such that it takes a Saturn V to launch a cubesat, it may simply cost too much to make it to the Moon.