Re:The EmDrive just won't die
by jiofih on Sunday September 13, 2020 @04:41PM
(#24463809)
The trick is not requiring propellant. You can’t carry 90 years worth of water or gas. The Dawn spacecraft launched to Ceres in 2007 used up 425kg of Xenon for only eleven days of thrust for its ion engine.
[ Parent
| on HN ]
If you let the fission fragments out the back of the reactor you get more thrust than this. (Even if the EmDrive worked).
You still need tons of fuel for that, in the order of tens of tons per year travelled - unrealistic for travel outside our solar system. Thrust doesn’t really matter at that time scale.
The fuel is the reactor fuel. Literally the fission products of the uranium/plutonium in your reactor, from where the power you want to use for the EmDrive comes from, would beat this.
If the EmDrive actually worked, the correct use is to violate conservation of energy and momentum, not as a straightforward substitute for the engines we have now.