Raptor is a new family of methane-fueled engines to be used in its future Starship rockets. Testing versions were test fired in late 2016. On April 3, 2019, SpaceX conducted a successful test in which the engine was started but the rocket was held down in Texas on its Starhopper vehicle, which ignited the engine while the vehicle remained attached to the ground. On July 24, 2019 SpaceX conducted a successful test flight of 20 meters up of its Starhopper test vehicle. On the 28th August 2019 SpaceX's Starhopper prototype conducted a successful test flight of 150-meters.