On this episode of Kickstarter of the Week, we are propelling a tiny solar-powered satellite into space using only water for fuel. The spacecraft could someday average over 1 billion miles per gallon.
The engine produces thrust through the expansion of a super-heated 350,000°C plasma, an ionized gas that can be accelerated to produce thrust. The gas could be one of many, including water vapor. It is turned into plasma for thrust by a radio frequency antenna. The force generated by the thruster is low, but very efficient.