The Electromagnetic Drive (EM) drive is a method of propulsion which is so clever scientists have not figured out why it works as it appears to break the law of conservation of momentum.
The “reactionless” Electromagnetic Drive, or EmDrive for short, is an engine propelled solely by electromagnetic radiation confined in a microwave cavity. It generates mechanical action without exchanging matter which is technically impossible.
Since 2010, both the United States and China have been pouring serious resources into it and the results seem promising. Now China claims it has made a key breakthrough.
Dr. Chen Yue, Director of Commercial Satellite Technology for the China Academy of Space Technology (CAST) announced that China had successfully tested EmDrives technology in its laboratories and its proof-of-concept is currently undergoing zero-g testing in orbit.
This test is taking place on the Tiangong 2 space station. If China can install EmDrives on its satellites for orbital manoeuvring and altitude control, they would become cheaper and longer lasting.
Li Feng, lead CAST designer for commercial satellites, states that the current EmDrive has only a thrust of single digit millinewtons, for orbital adjustment; a medium sized satellite needs 0.1-1 Newtons. A functional EmDrive would open new possibilities for long range Chinese interplanetary probes beyond the Asteroid belt, as well freeing up the mass taken up by fuel in manned spacecraft for other supplies and equipment to build lunar and Martian bases.