Reply To: Investment risk

[Ferret]

opensource wrote: What we’re talking about I think – to be quite vague – is a technology that best converts between energy and matter. The more of the latter you have, the more effective the propulsion system will be in this sea of gas and gravitation. Sound right?

Generally, a rocket engine is more effective in terms of fuel used when it puts more energy into less matter. Energy means kinetic energy. Thus, an efficient rocket engine has higher exhaust speeds for less matter exhausted. For atmospheric engines things change a bit, since air may be taken in and used as the exhaust. But basically you still want to use the least amount of fuel.

Now for FF atmospheric propulsion, one would probably have to send the FF ion jets into a heating chamber, where they heat the air, which is then expelled to the back. It is much like a turbojet or a ramjet engine, only you use the FF exhaust to heat the air instead of burning some petroleum fuel. In terms of fuel used, this is much more efficient than a jet engine, since you use nuclear energy and the fuel quantity is some 1 000 000 times smaller. It remains to be seen whether it is more efficient in terms of engine mass, too. You don’t want a huge, heavy engine to do the same work as a jet engine. If you wanted that, the solution were right around the corner: a thermal nuclear fission reactor powering an aircraft engine. Think about an aircraft carrier power source on an airplane.