Thursday, May 27, 2010
VASIMR is often seen in the news as the next generation of propulsion that will be able to bring trip times to Mars down from six months to about 40 days (though this also requires a large power source in order to happen), but little is said about its application on other destinations as well. This pdf is a good overview of some of the missions in which VASIMR would bring an efficiency not present now. Since VASIMR is a type of ion engine it has a much lower thrust than a chemical engine but much higher efficiency, resulting in much higher velocities over the long term than a traditional rocket. As the pdf shows though, when sending cargo to the Moon its greater efficiency can also be used to save a lot of space and increase the amount of payload that can be sent, as long as there is no need for haste. A trip to the Moon using VASIMR in this way would take six months (with a chemical rocket it's only about three days), in a trip that involves an ever-expanding orbit around Earth, then finally breaking orbit and heading to the Moon, entering orbit there and slowly moving into a closer and closer orbit after which it can be considered to have arrived.