What do you do with an old Learjet?
If you’re George French and David Urie, you send it into orbit.
French, who is president and CEO of Rocketplane Ltd., Inc. and Urie, the company’s vice president and program manager, are modifying Learjet 25 airframes as platforms for re-usable spacecraft, capable – they say – of carrying four passengers to sub-orbital altitudes of up to 330,000 feet. They call it the Rocketplane XP.
The company was started four years ago and began operations last June, after obtaining – and selling — $13 million in transferable investment tax credits from the state of Oklahoma. They intend to develop a sub-orbital tourist business at the Oklahoma Spaceport in Burns Flat, with first revenue flights planned for 2007.
The Rocketplane XP will start as a stripped Learjet 25 fuselage. It will be fitted with new wings, new turbofan engines, and an Orbital Technologies re-usable rocket engine. (Dr. Eric Price, president of Orbital Technologies, is a Rocketplane board member.) The rocket will use liquid oxygen and kerosene as its propellant.
The idea is to fly to 30,000 feet on turbofan power, then light off the rocket, which will take the plane to about 158,000 feet. From there it will coast to its 330,000 foot apogee, ultimately gliding back to Earth on its very basic wings. Urie commented that the wing doesn’t have to offer much more than lift for takeoff and climb, and a reasonable surface for gliding home. There is no need for cruise efficiency because there is no cruise, he said. Passengers can expect a half hour flight with about four minutes of weightlessness at the apogee.
The Learjet 25 was chosen because it is a very strong and durable airframe, some models of which already are certified to 51,000 feet, according to Urie. The pressure difference between 51,000 feet and 330,000 feet is very slight, but the company plans to “burst” one fuselage during pressure tests, to determine its limits.
Learjets in space. Bill Lear would be proud.
