The Daedalus Propulsion System

The idea of rocket propulsion is somewhat familiar to most people, in the sense that it is understood that gases are ejected at high pressure from the rear of a spacecraft, and that this ejection generates thrust. Rocket propulsion is ideal for launching spacecraft from the Earth, because the amount of force generated by the fuel is huge. However, one of the drawbacks of conventional rockets is their low exhaust velocity; that is, only a relatively small amount of net energy can be liberated from the fuel, when compared with, say, nuclear fuel. This drawback means that to accelerate an object to very high speeds, say a reasonable fraction of the speed of light, that a huge amount of fuel would be required. In fact, some fairly simple calculations using the Tsiolkovsky rocket equation demonstrate that to accelerate a spacecraft to about 10% the speed of light would require more propellant than is available in the known universe! Clearly  chemical rocket fuels are inadequate for the task of interstellar propulsion if travel times are to be on the order of a human lifespan. (more…)