However, Rutan and backers are not talking about the inherent capability of using this system as a low-cost, rapid response military satellite launcher. In the existing system, a large carrier aircraft dubbed "White Knight" hauls the 6,600 pound SpaceShipOne to around 50,000 feet. SpaceShipOne is released, drops away from the carrier, and then ignites a hybrid motor that uses rubber and nitrous oxide as fuels as it rockets up to an altitude of over 100 kilometers (63 miles) the "official" height where the atmosphere ends and space begins. It coasts for a minute or two before gliding back to earth and landing on a runway. There's a minimal ground crew and mission control fits into the back of a large truck.
Depending on the design requirements, several different derivative vehicles could be slung under the "White Knight." The most obvious version would be an expendable booster designed to loft a small payload into low earth orbit. Orbital Sciences Corporation already does this with its Pegasus booster, using a converted L-1011 widebody commercial airliner to lift the solid rocket booster up to 40,000 feet. Pegasus is capable of putting up to 1,000 pounds into low earth orbit at a cost of between $15-20 million per launch. Since there's a lot of "dead weight" in SpaceShipOne for items such as wings, flight control systems, life support for the pilot, and the like, developing an expendable booster based on a derivative of SpaceShipOne should be relatively straight-forward. With a little more effort, a reusable rocket stage could be designed to either parachute or fly back to earth.
How useful is 1,000 pounds to low earth orbit? A number of imaging satellites weighing in between 240 to 1000 pounds are in operation today. For example, Israel's Ofek-5 weighed in at 660 pounds at launch when put into orbit in June 2002 and is capable of taking pictures with a resolution of 1 meter good enough to tell the difference between a tank and a car and spot a group of tanks assembling for attack. The TacSat-1 experimental satellite scheduled for launch this fall weighs under 240 pounds and carries an infrared camera, regular camera, and a radio signals collection package.
Scaled Composites is also no stranger to the Department of Defense. The company has built several different aircraft prototypes for Army, DARPA and Navy projects, plus has worked on various classified projects. The total bill for the SpaceShipOne project is around $20 million and Scaled is notoriously frugal, so even a one-time injection of $3-5 million could likely produce at least one derivative unmanned launcher to complement privatized manned space launch efforts.
At the end of September, Scaled Composites SpaceShipOne will be competing for a $10 million dollar prize. If the privately-funded manned vehicle can make two trips to 100 kilometers altitude twice in two weeks, carrying the pilot and the weight/volume equivalent of two additional passengers, it wins the money. The Ansari X prize is designed to stimulate efforts to privatize space flight and drive launch costs to orbit downward. SpaceShipOne designer and aviation legend Burt Rutan has been making the rounds discussing how the current three-man suborbital vehicle could evolve into a one-man orbital vehicle capable of a round-trip flight to 130 kilometers and an orbiting space "hotel."