http://www.aviationnow.com/avnow/noys/noys_story.jsp?id=news/SSO11014.xml

By Jefferson Morris

11/01/2004 09:00:46 AM

SPACESHIPONE LESSONS FEEDING INTO RASCAL AIRCRAFT - Lessons and technology from Scaled Composites' SpaceShipOne are being applied to the supersonic manned aircraft the company is developing for the Defense Advanced Research Projects Agency's (DARPA) RASCAL program, according to Jacob Lopata, chief executive officer for RASCAL prime contractor Space Launch Corp. The RASCAL (Responsive Access, Small Cargo, and Affordable Launch) aircraft is one element of a two-part system for launching small payloads quickly and affordably into low-Earth orbit. The other part of the system is a two-stage expendable rocket that would be released from the RASCAL aircraft when it reaches the edge of the Earth's atmosphere.

"We consider SpaceShipOne to be a significant risk mitigation step for us," Lopata said to the FAA's Commercial Space Transportation Advisory Committee (COMSTAC) in Washington last week. "A lot of the things that Scaled has learned during the course of their program will directly benefit the RASCAL program.

"They're learning a lot about flight paths in a regime that they didn't have any experience in up until this point," Lopata said. "SpaceShipOne and RASCAL will be operating in a very similar environment in terms of speed and altitude." The RASCAL aircraft also will feature the same thermal protection system used by SpaceShipOne, he said. The RASCAL aircraft will be powered by four mass-injection pre-compressor cooled (MIPCC) turbojet engines. After takeoff from Mojave Airport in California, the aircraft will climb to 50,000 feet and then perform a supersonic "zoom" maneuver until it reaches 100,000 feet altitude. At that point the engine will shut off and the aircraft will coast on a ballistic trajectory to approximately 180,000 feet, where the rocket is released. The rocket will feature a hybrid first stage and a solid-fuel second stage.

Among the program's performance goals are 75 kilograms (165 pounds) of payload delivered into a 500-kilometer (310-mile) sun-synchronous orbit, a mission turnaround time of 24 hours from payload arrival, and recurring launch costs of $750,000 per flight.

Despite DARPA's emphasis on MIPCC turbojet engines for RASCAL, if the technology runs into difficulties the program won't necessarily be "wedded" to it, according to Lopata. However, "from a ground testing standpoint and an analytical standpoint, [MIPCC is] doing everything we expected it to do," he said.

The RASCAL program is "a few days" from the end of its second phase, and is awaiting approval to move into a 36-month demonstration phase that would culminate in two flights in 2008, according to Lopata. "The challenge is now, can we convince ... the government that we can integrate this aircraft, integrate this system?" he said. "And that's what we're working very hard to do now."