Previous article about the engine (from 2011) http://www.sciencedaily.com/releases/2011/10/111006084023.htm.<p>Video from the tests: http://www.youtube.com/watch?v=RP48Eb4lr54<p>Surpsisingly engine worked at the first try in simulated space conditions :)<p>Engine has mass of 4kg, and length of 12 cm. It' meant for adjusting orbit and manouvering in space of probes with mass around 100 kg.<p>It uses krypton (33$ per 100g) instead of Xenon (120$ per 100g) as propellant so should be much cheaper, while it's simillary efficient as other thrusters.