[Capitalism2003]

curious...How fast can this thing go?

[petuniasevan]

The ion propulsion system on Deep Space 1 carried about 81.5 kilograms of xenon propellant, and it took about 20 months of thrusting to use it all. It increased the speed of the spacecraft by about 4.5 kilometers per second, or about 10,000 miles per hour. This of course was in addition to the speed imparted by the launch into space, and any and all "slingshot" gravity assist maneuvers.

Under the circumstances for which ion propulsion is appropriate, it can push a spacecraft up to about ten times as fast as chemical propulsion. Because the ion propulsion system, although highly efficient, is very gentle in its thrust, it cannot be used for any application in which a rapid acceleration is required.

Missions to the Moon wouldn't use this technology, for example. Neither would manned missions to Mars. It would be in the future Mars-bound astronauts' best interest to get to Mars ASAP.