Sen—Microsoft founder and billionaire Paul G Allen is funding a radical new launch system to send spacecraft into orbit from a high-flying aircraft.
A giant twin-fuselaged jet plane will carry vehicles that could hold cargo or crew to an altitude of 10,000 meters before releasing them to rocket into space.
If the design looks familiar, it is because it is a scaled-up version of the White Knight/SpaceShipTwo configuration that Virgin Galactic will use to carry tourists to the edge of the final frontier.
The revolutionary new system's carrier aircraft is being developed by aerospace pioneer Burt Rutan's company Scaled Composites which designed the Virgin hardware. It will be the largest plane ever built, with a wingspan of 385ft and powered by six engines of the type used by Boeing 747 jumbos.
The aircraft will be so large that it will have to take off from especially long, 12,000ft runways, such as that at Kennedy Space Center, Florida, that was used to land the Space Shuttles.
Once it has reached high altitude, the plane will drop the booster that it has carried between its twin hulls and this will then fire its rocket engines to continue the journey into orbit.
The company developing the new technique is Stratolaunch Systems, and its largely reusable design looks set to challenge the space delivery methods being developed by Alan Bond's UK-based Skylon, though using more conventional technology.
The developers say their air-launch system will allow access to low-Earth orbit - the zone where the International Space Station flies - with greater safety, cost-effectiveness and flexibility than launching rockets from the ground.
They will be able to have a quick turnaround between missions and, by operating above the clouds, avoid the delays that can hamper rocket launches from the ground.
Allen has worked with Rutan before. Their partnership saw the development of Rutan's SpaceShipOne, the first privately-funded, manned rocket ship to fly beyond Earth's atmosphere. It won the $10 million Ansari X PRIZE in 2004 after successfully making two sub-orbital flights within a two week period.
Allen said: "I have long dreamed about taking the next big step in private space flight after the success of SpaceShipOne – to offer a flexible, orbital space delivery system. We are at the dawn of radical change in the space launch industry. Stratolaunch Systems is pioneering an innovative solution that will revolutionise space travel."
The 540-tonne carrier aircraft, which should be ready for testing by 2016, will be built in a new hangar at Mojave Air and Space Port in southern California.
The multi-stage booster it will carry is being manufactured by Elon Musk's Space Exploration Technologies (SpaceX) who developed the Falcon 1 and Falcon 9 rockets and Dragon spacecraft that is due to make commercially-operated flights to the International Space Station.
The third partner in the new venture is leading aerospace engineering company Dynetics, of Hunstville, Alabama, who will produce the mating and integration system to allow the aircraft to carry the spacecraft safely.
The Stratolaunch Systems team has an impressive line-up. Apart from Allen and Rutan, it is being led by CEO and President Gary Wentz, a former chief engineer at NASA. And former NASA Administrator Mike Griffin is on the board.
Early flights from the mobile launcher will focus on launching commercial and government payloads into space. Only when these have proved its safety and reliability will human missions be launched.
Virgin's Richard Branson praised the new launch system as "very exciting" and "a historic day for space travel" on his blog. He added: "This is a long term project and will initially be for unmanned flight, but eventually may be capable of helping to take people into orbit. One day, Virgin Galactic will be offering orbital spaceflights in addition to our sub-orbital space experience."