> These ion thrusters have worse thrust/watt than an electric propellor drive, and far worse than the jet engines they use.
From the Ars article (for others who were curious about this):
> Measurements showed the thrusters collectively generated five newtons for each kilowatt of power, which is actually similar to the output of jet engines. But because of many inefficiencies in the system, the overall efficiency was only about 2.5 percent—well below that of conventional aircraft.
From the Ars article (for others who were curious about this):
> Measurements showed the thrusters collectively generated five newtons for each kilowatt of power, which is actually similar to the output of jet engines. But because of many inefficiencies in the system, the overall efficiency was only about 2.5 percent—well below that of conventional aircraft.