Saw this last night while googling around. Liquid bi-propellent engine, website claims 233 sec ISP, 2500 lbf, and a >60 sec burn time. I've never heard of a "triplet" injector before. Really cool stuff, i hope they're successful. http://www.burocket.org/lotus-dev-2 PS All of their engines are very impressive. "The Mk. IIB had the first successful implementation of liquid injection thrust vector control on a hybrid rocket motor" that is very cool!