VASIMIR thought experinment

[aquitaine]

Ok, so we've all been hearing about the VASIMIR in recent years. If we were to use something like that to lift something off of the Earth (like or rocket or horizontally like a jet), how much power would it need? I'm guessing an order of magnitude more than the 200kW version currently being developed for space only purposes.

 

[hamster143]

VASIMR has high specific impulse and therefore low thrust to power ratio. To lift a meager 1 ton spacecraft off the surface of the planet, you need thrust of 10^4 Newton. Assuming specific impulse of 3000 s (exhaust velocity 30 km/s, on the low end for VASIMR), you need W = T*v/2 = 15 megawatt.