It's a Rocket! It's a Plane! It's...Rocket Plane!

Business Class-In 4 Gs

In early 2004, as one of his first acts as Rocketplane´s president, French hired aerospace engineer David Urie as Rocketplane´s engineering guru. (Clapp left the company shortly afterward, citing â€creative differences†with the company´s new management.) A 30-year veteran of aerospace giant Lockheed Martin and its famously secretive Skunk Works design lab, Urie oversaw, among other projects, the development of the X-33 Venture Star, the ship that NASA hoped would replace the space shuttle in the 1990s.

At Rocketplane, Urie immediately began recruiting a mix of veteran engineers and recent grads to pull off his feat. One of his key acquisitions was Bob Seto, Learjet´s program manager for all its models. Seto says that using an existing fuselage instead of designing one from scratch gives Rocketplane a running start in the new space race. â€There´s a big cost to designing the details of a fuselage,†he says. â€Purchasing the fuselage reduced a lot of that risk and development effort. We don´t have to spend a large amount of time starting from a blank sheet of paper.â€

Aiding the effort is the fact that the Learjet is exceptionally well suited to the task. The Learjet 25 was designed for more than three Gs of acceleration, which puts it in the ballpark of what the Rocketplane XP will encounter during its rocket-powered ascent and turbulent reentry. The XP´s new, stronger delta-wing assembly and a reengineered tail will give the craft the increased structural strength it needs to survive 4-G flight. To cope with atmospheric heating on reentry, the ship will rely on a protective coating developed at NASA´s Ames Research Center. The nose, the leading edges of the wing structure, and the jet engine inlets will be titanium, which can withstand higher temperatures than the aluminum used elsewhere in the craft. All these modifications come with a weight penalty. At 19,500 pounds takeoff weight-4,500 pounds more than the Learjet 25-the XP will need plenty of runway to get airborne, so it will take off and land from the 13,500 foot strip built for B-52 bombers at the former Strategic Air Command base at Burns Flat, Oklahoma.

Inside the â€Space Limoâ€

Aerodynamics engineer Gary Lantz, recruited from leading small-aircraft manufacturer Cessna, describes the Rocketplane XP as a â€space limo†because of the limited number of passengers it can carry. Reda Anderson likes that term because it conveys exclusivity: more passengers on board would make for more of a space bus, and that´s not the kind of experience she wants. â€I like world-class events,†she says-like the private dive to the wreck of the Titanic she took last year-and she doesn´t want to share it with a gaggle of other people. Nor does she mind that the XP´s relatively cramped interior will prevent passengers from floating around the cabin in zero G. It´s the
view she´s after, not a few minutes of free-floating weightlessness.

Rocketplane´s engineers and contractors say their plan will send Anderson to space before SpaceShipTwo´s planned 2008 or 2009 launch. But will it work? Nesrin Sarigul-Klijn, professor of mechanical and aeronautical engineering at the University of California at Davis and a spacecraft-design consultant for commercial space companies t/Space and SpaceDev, has doubts. She fears that the beefed-up Learjet fuselage and the heavy engines will weigh too much. â€The first thing they will run out of is propellant,†Sarigul-Klijn says, â€and then when they add more propellant, they will run out of volume to put people in.â€