Tier 1b

Tier 1b is Burt Rutan's nickname for the suborbital tourist human spaceflight platform in development at Scaled Composites with Mojave Aerospace Ventures by The Spaceship Company for Virgin Galactic. It is an evolutionary development of Tier One, the Ansari X-Prize winning entry in the demonstration suborbital space tourism contest held by the X-Prize Foundation.

White Knight Two will be an aircraft capable of attaining an altitude of at least 50,000 ft (15,000 m) or 15 km and be aerobatic, offering several seconds of weightlessness. This will allow space tourists to train before their flight. White Knight Two will have a twin-boom design, with SpaceShipTwo nestled between the two hulls. One hull will contain tourists on zero-g flights, the other hull will contain astronauts in training, and be identical to SpaceShipTwo's cabin. White Knight Two is a development upon the White Knight (or White Knight One) design.

SpaceShipTwo will have a cockpit similar to SpaceShipOne, and a large cabin to allow tourists to float weightlessly. It is anticipated that the flight profile will allow for 4 minutes of weightlessness and 40 seconds transition from weightless to one g. SpaceShipTwo is a development upon the SpaceShipOne design.

White Knight Two will carry SpaceShipTwo up to launch altitude, where it will be air launched, and will rocket through suborbital trajectory.

The launch customer of Tier 1b is Virgin Galactic, which will have the first two WK2 units, first five SS2 units, and exclusive rights to the craft for the first few years.

The first WK2 was rolled out on July 28, 2008 and named VMS Eve. Its first test flight was on December 21, 2008.

External links

• SPACE.com : Burt Rutan on Civilian Spaceflight, Breakthroughs, and Inside SpaceShipTwo (Leonard David) 11 August 2006 03:54 pm ET