Project Orion is the best way given our current level of technology. Not many people know about it because Von Braun and his rockets won out, but this technology is possible and our best bet. It has no limitation on weight since it has a high specific impulse and a high thrust. In this article it was called "pulse nuke propulsion" (#3).
http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)
The pulse nuke system might be fine for the first ship going out in a particular direction, but wouldn't any other future ships have to travel through the nuclear radiation left behind by the first ships trail of nuclear explosions?
It kind of poisons the well doesn't it?
Nothing is static in space. The problem isn't so much about leaving a trail, but rather that the trail is pulled into the closest gravity well (for example, Earth). They can made very cleanly though and they're rather small nukes. It's too bad we can't make fusion bombs because those would work better and be much, much cleaner.
I still like the boobie one.
Edit: Does all the talk about thrusters science get anybody else all heated up?
Sure, but I'd be more excited if SpaceX were not the only company that cared about space...
And I prefer my boobies in pairs. That fusion drive has far too many. :)
Maude_Lynne
I like the boobie one!