>> Wednesday, October 7, 2009
Jeff King asked: What alternative rocket fuel do we have to look forward to, to help our stagnate space program to take the next big leap?
I don't know that new fuels are the key. With all our technologies, hydrogen/oxygen are still the most efficient of rocket fuels, but cryogenic support systems are expensive, complex and prone to failure. H/O and hypergolics (like hydrazine) dominate here in the US. Russia has an amazing launch record using almost exclusively kerosene-based rocket fuels (which have the advantages of liquid based throttle-ability without the problems of cryogenics). Hydrogen peroxide has also been touted as potential fuel.
But most if not all of the fuels we're talking about are effectively the same ones from 40 years ago. When it comes to lifting off the planet, we're still using traditional methods. However, once you're in orbit (or a transition orbit), there are alternate methods of propulsion, like for interplanetary travel, that move beyond the traditional fuels.
Among the possible methods of propulsion that have potential, however, there are several nuclear possibilities, including using radioisotope rocket, electric propulsion, and solar sails.