/sci/ - Science & Math

This question has been bugging me for a while.

What forms of space travel are not limited by reaction mass?
There are a few obvious ones like a solar sail or optical resonance mirrors, which each get their reaction mass from their energy source, but they are very limited. I'd count a bussard ramjet because it uses a portion of its energy to collect more reaction mass, but that's not pheasible with current technology. I suppose memedrive might count too if anyone can prove it works.

So far the only other contenders I've been able to come up with is a craft with a powerful laser to propel it which is similar to the solar sail but less efficient, and a nuclear-powered ion drive that expels spent fuel as reaction mass but that doesn't technically meet the criteria and its wasteful.

I feel like I'm missing some obvious solutions

>>9829949 #
>>9830151 #
Furst one nen da udder