DARPA, NASA, JPL and various aerospace giants are rushing to learn more about a massless thruster developed by Dr Young Bae: http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=201804852 http://www.photonics.com/content/news/2007/September/7/88894.aspx At the claimed millinewtons of thrust, it may be applicable for orbital maneuvering. However, the claim is also being made that it could be scaled up to deliver kilonewtons of thrust, given enough power (from a nuclear reactor, for example) Wow, that would be pretty amazing, not to have to carry propellant mass with you. But I wonder how efficient the power coupling/conversion is? What are the limitations on how far it can be scaled up? Are kilonewtons really possible? And of course, is this phenomenon really legitimate? I'd really like to hear comments/feedback.