An advanced rocket engine design project named Raptor—then a hydrolox engine—was first publicly discussed by SpaceX's Max Vozoff at the American Institute of Aeronautics and Astronautics Commercial Crew/Cargo symposium in 2009.[1] As of April 2011[update], SpaceX had a small number of staff working on the Raptor upper-stage engine, then still a LH 2/LOX concept, at a low level of priority.[42] Further mention of the development program occurred in 2011.[43] In March 2012, news accounts asserted that the Raptor upper-stage engine development program was underway, but that details were not being publicly released.[44]