NASA Studying Solar Powered "Space Tugboat" 86
Zothecula writes "Last year, NASA announced it was seeking proposals for mission concept studies of a high-power solar electric propulsion (SEP) system that could be used in a 'space tugboat.' Such a ship would be used to ferry payloads in low Earth orbit (LEO) into higher energy orbits, including geosynchronous Earth orbit (GEO) and Lagrange point one (L1) — saving on fuel and the use of expensive secondary boosters. NASA also anticipates an SEP system could be used to propel spacecraft into deep space for science missions and for the placement, service, resupply, repositioning and salvaging of space assets by commercial operators."
Re:Electricity source (Score:5, Informative)
The sterling engine work that NASA is doing is to make the RTGs more efficient - this is not for propulsion but for providing power to other systems on the spacecraft (avionics, transceiver, instruments). Part of the motivation is to reduce weight, or to get more power for the same amount of weight. The other issue is that the isotopes which are commonly used for RTGs were byproducts of nuclear weapon production, hence, have not been produced (in America, at least) for decades.
Casamir effect thrusters? (Score:5, Informative)
Do you mean VaSIMR?
http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket [wikipedia.org]
Or Hall Effect Thrusters?
http://en.wikipedia.org/wiki/Hall_effect_thruster [wikipedia.org]
And Ion Thrusters of various types have been used as primary propulsion n space successfully ever since Deep Space 1. They've been used for satellite orientation and station keeping for decades. They are vastly more efficient than chemical thrusters, reducing the amount of propellant you need to carry, and therefore reducing launch costs.