Hopefully Interesting

See also parts  I ,  II ,  III ,  IV , and  V . Chemical rockets would be really nice if they were just a bit more energetic.  The energy that goes into pushing the propellant out comes from the propellant itself, so there's stuff you can do to minimize the transmission of heat from the propellant to the rest of your engine.  That helps you get around some of the problems of rockets where you  heat up the propellant  from outside.  And the fact that you're still basically using heat means you don't have to suffer the efficiency losses that happen turning heat to electricity when you use an  electric rocket .  But what sort of reactions are there that we might cause in our propellant that are higher energy than chemical reactions?  I think you've all seen the post title and know that I'm about to say "nuclear." Now I should make sure to say that unlike the other categories I've mentioned nobody is actively working on any of these.  In the case of s

See also parts  I ,  II ,  III ,  IV ,  and  VI . We've covered a bunch of ways of moving ships around in space by shoving stuff out their backs.  But there are some ways of moving around in outer space that actually don't involve the rocket equation at all.  When you fly in a plane on Earth you can push around all that nice air that surrounds you in your environment in order to fly.  Well, you can if you have a plane.  It's very convenient in terms of not having to carry around huge amounts of fuel.  There isn't any air in space but that doesn't mean that space is entirely featureless either.  There are basically three things I know of that you can push off against in order to go places in space: the light of the sun, the solar wind, and planetary magnetic fields. The principle behind solar sails is pretty simple.  You still have sunlight in space and it's very bright too, at least within Earth's orbit.  By Einstein's good old e=mc 2 we know that s