Added 1 new A* page:SpaceX launches electric satellites is a BBC article covering today's launch of two commercial satellites by the space flight company SpaceX, and it makes a point of discussing the fact that these satellites use electrically boosted xenon ions for propulsion, rather than conventional gas-burning thrusters. Such ion drives have been more and more popular with European and Asian space vehicles in recent years, for instance there was the Japanese Hayabusa probe that returned material from asteroid 25143 Itokawa in 2010, and the European SMART-1 satellite that used an ion thruster to reach the Moon in 2004. As the BBC article puts it,|
|The efficiency of electric thrusters does away with the bulky fuel tanks required by traditional chemical engines. [...] The downside is that it takes longer for a spacecraft to get into position once it is dropped off in orbit - on the order of months rather than weeks.|
It appears that the first working ion thruster was built by NASA in 1959. NASA conducted successful test missions of ion engines in 1964 and 1970 (SERT I and II), but it was the Soviet Union who really ran with the technology, using hundreds of ion engines on satellites from the '70s through the '90s. NASA has run successful tests of ion drives running steadily for years on end; in one such test, the engine was 12 times more efficient than an conventional chemical thruster would have been, per kilogram of propellant. NASA's first spacecraft to use an ion drive was 1998's Deep Space 1, which made a flyby of asteroid 9969 Braille and Comet Borrelly. The US military and Boeing have used ion thrusters in their satellite projects, and let's not leave out NASA's Dawn probe, currently closing in on the dwarf planet Ceres with its ion drive.