Peter Siebold is a member of the Scaled Composites astronaut team. He is their Director of Flight Operations was one of the test pilots for SpaceShipOne and SpaceShipTwo. On October 31, 2014, Peter Siebold and Michael Alsbury were piloting the SpaceShipTwo VSS Enterprise on flight PF04, when the craft came apart in mid-air and then crashed, killing Alsbury and injuring Siebold.