4 ms·
With ion engines, you need fuel to be ionized - usually xenon. The faster you want to go, the more of your energy just goes toward accelerating the fuel in your
by skykooler 7y ago
With ion engines, you need fuel to be ionized - usually xenon. The faster you want to go, the more of your energy just goes toward accelerating the fuel in your tank. The upper limit for speeds you can reach approaches the speed of the exhaust - which tops out around 50 km/s for current ion drives, about .0002C.
- adwn 7y ago> The upper limit for speeds you can reach approaches the speed of the exhaust - which tops out around 50 km/s for current ion drives, about .0002C. That is not correct. The delta-v of a rocket (i.e., the maximum speed it can reach) depends on the effective exhaust velocity and on the mass fraction of its propellant; see [1]. For example, a rocket which is initially 90% propellant, can reach a velocity ~2.3 times its effective exhaust velocity. [1] https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation
- skykooler 7y agoFair enough. Either way, the fuel requirement makes it pretty much impossible to reach a significant fraction of the speed of light with ion engines.