The Emdrive is an electromagnetic drive that would generate thrust from a closed system — “impossible” say some experts.
To critics, it’s flat-out junk science, not even worth thinking about. But its inventor, Roger Shawyer, has doggedly continued his work. As Danger Room reported last year, Chinese scientists claimed to validate his math and were building their own version.
Shawyer gave a presentation earlier this week on the Emdrive’s progress at the CEAS 2009 European Air & Space Conference. It answered few questions, but hinted at how the Emdrive might transform spaceflight — and warfare. If the technology works, that is.
The heart of the Emdrive is a resonant, tapered cavity filled with microwaves. According to Shawyer, a relativistic effect generates a net thrust, an effect confirmed by various Emdrives he has built as demonstrations. Critics say that any thrust from the drive must come from another source. Shawyer is adamant that the measured thrust is not caused by other factors.
While the argument over the drive’s impossibility continues, so does the engineering work. The problem is that nobody wants to talk about it. Even Shawyer gives little away.
Last year, professor Yang Juan of the College of Astronautics at Northwestern Polytechnical University (NPU) in Xi’an was happy to confirm that they were building an Emdrive which would be tested by the end of the year. But following the publication of this news in Danger Room, the situation changed. I was informed that the publicity was very unwelcome, especially any suggestion that there might be a military application. (Yang had previous published a study on the use of plasma as a weapon against low-orbiting satellites. [.pdf]) No further information has been forthcoming, and no Chinese papers have been published on the Emdrive, though Yang has recently published work on (unrelated) microwave plasma thrusters (.pdf).
Shawyer asserts that work is also being carried out in France, Russia and in the United States by a major aerospace company. But he cannot provide details beyond vague promises of “significant progress [that] has been made in both theoretical and experimental work, within these groups.” He also asserts that the British National Space Centre is said to be reviewing the Emdrive. Again, no details.