Peter Siebold is a member of the Scaled Composites astronaut team http://www.space.com/php/multimedia/imagegallery/igviewer.php?imgid=1858&gid=154 and was one of the test pilots for SpaceShipOne, the experimental spaceplane

Spaceplane

A spaceplane is a vehicle that operates as an aircraft in Earth's atmosphere, as well as a spacecraft when it is in space. It combines features of an aircraft and a spacecraft, which can be thought of as an aircraft that can endure and maneuver in the vacuum of space or likewise a spacecraft that...

 developed by Scaled Composites

Scaled Composites

Scaled Composites is an aerospace company founded by Burt Rutan and currently owned by Northrop Grumman that is located at the Mojave Spaceport, Mojave, California, United States...

.http://www.space.com/missionlaunches/spaceshipone__secretpilot_040618.html On 8 April 2004, Siebold piloted the second powered test flight of SpaceShipOne, flight 13P

SpaceShipOne flight 13P

Flight 13P of SpaceShipOne was its second powered flight, which occurred on April 8, 2004. The pilot was Peter Siebold.SpaceShipOne was released from White Knight at an altitude of 45,600 ft . Ignition was delayed by about two minutes to evaluate a shock-induced stall buffet...

, which reached a top speed of Mach 1.6 and an altitude of 32.0 kilometers.

Siebold holds a degree in aerospace engineering

Aerospace engineering

Aerospace engineering is the primary branch of engineering concerned with the design, construction and science of aircraft and spacecraft. It is divided into two major and overlapping branches: aeronautical engineering and astronautical engineering...

 from California Polytechnic University

California Polytechnic State University

California Polytechnic State University, or Cal Poly, is a public university located in San Luis Obispo, California, United States. The university is one of two polytechnic campuses in the 23-member California State University system....

; a design engineer at Scaled Composites since 1996, Siebold was responsible for the simulator, navigation system, and ground control system for the SpaceShipOne project.

Although he was one of four qualified pilots for SpaceShipOne, Siebold did not pilot the craft during the flights later in 2004 to meet the requirements of the Ansari X Prize

Ansari X Prize

The Ansari X Prize was a space competition in which the X Prize Foundation offered a US$10,000,000 prize for the first non-government organization to launch a reusable manned spacecraft into space twice within two weeks...

.http://web1-xprize.primary.net/downloads/ScaledComposites.pdf Although Siebold flew SpaceShipOne to an altitude of 32 km (just under 20 miles), he did not cross the 100 km Kármán line

Karman line

The Kármán line lies at an altitude of above the Earth's sea level, and is commonly used to define the boundary between the Earth's atmosphere and outer space...

 -- the international standard for reaching space.

For his contribution to the project, Siebold received the 2002 Iven C. Kincheloe Award

Iven C. Kincheloe Award

The Iven C. Kincheloe Award recognizes outstanding professional accomplishment in the conduct of flight testing. It was established in 1958 by the Society of Experimental Test Pilots and honors the memory of test pilot and Korean War ace Iven C...

 presented by the Society of Experimental Test Pilots

Society of Experimental Test Pilots

The Society of Experimental Test Pilots is an international organization that seeks to promote air safety and contributes to aeronautical advancement by promoting sound aeronautical design and development; interchanging ideas, thoughts and suggestions of the members, assisting in the professional...

.

He was the pilot who flew the White Knight Two on its maiden flight on the 21st of December 2008. http://www.scaled.com/news/wk2_21_12_08.pdf