 NASA formally approved the mission to the ISS on a 2013 launch slot in May 2012.The mission had been slated to travel to the ISS in the unpressurized cargo compartment of a SpaceX Dragon spacecraft during one of the contracted NASA cargo re-supply missions in mid-2013.The "ISPS NOFBX Green Propellant Demonstration" will utilize a deep-throttling -thrust-class engine burning NOFBX rocket engine that will be mounted to the outside the European Columbus module on the ISS, and had been expected to remain on-orbit for approximately one year while undergoing a "series of in-space performance tests."