The RASCAL could have been the first practical orbital launch system for small payloads, had DARPA not shifted priorities...

Three views of initial DARPA/Scaled Composites concept.

Sub-scale hybrid motor testing to acquire burn rate data
for the design of the heavy weight motor.

Description of a typical RASCAL mission

Type: two-stage, orbital air launch system



Powerplant: 4 x Mass Injection Pre-Compressor Cooling (MIPCC) F100s

Significant date: 2002

The Defense Advanced Research Projects Agency (DARPA) started work in 2002 on a project to create a low-cost, partially-reusable launch vehicle for small payloads. The project was seen as a potential solution to the U.S. military’s need for operationally responsive spacelift (ORS). This ORS requirement was expressed in a USAF mission need statement in 2001. The RASCAL (Responsive Access, Small Cargo, Affordable Launch) program sought to develop a two-stage air launch system that could place payloads weighing up to 100 kilograms (221 pounds) into LEO. This capability would provide a means for rapid launch of orbital assets for changing national security needs. In many respects, the mission requirements are similar to the Bantam-X effort of several years prior (see insert).

The RASCAL was a two-part system for launching small payloads quickly and affordably into low-Earth orbit. The RASCAL first stage was to be an air-breathing jet aircraft that flew to an altitude of at least 55 kilometers (34 miles). The aircraft would then deploy an expendable rocket to place the payload into orbit. The vehicle was to put at least 50 kilograms (110 pounds) into any inclination, including 75 kilograms (165 pounds) into Sun-synchronous orbit (SSO) and heavier payloads into equatorial orbits. The RASCAL vehicle would be able to take off within 1 hour of a launch command and refly again within 24 hours at a cost of no more than $10,000 per kilogram per flight. To achieve these performance goals, RASCAL was to use an engine technology called Mass Injected Pre-Compressor Cooling (MIPCC) on its aircraft stage. A MIPCC engine is a conventional turbojet with an additional stage that injects a coolant, such as water or liquid oxygen, into the engine inlet. The other part of the system was a two-stage expendable rocket that would be released from the RASCAL aircraft when it reached the edge of the Earth's atmosphere.

In March 2002, Pioneer Rocketplane was awarded a Phase 1 contract by DARPA for the RASCAL program, along with five competitors: Coleman Research Corp., Northrop Grumman Corp., Space Launch Corp., Space Access LLC, and Delta Velocity. The RASCAL program also involved the contribution of Rutan, through the Scaled Composites design team. Then in 2003, DARPA selected Space Launch as the only RASCAL Phase 2 award winner. Scaled Composites was on the Space Launch Corporation team and was designing the RASCAL airframe. Phase 2 was an 18-month design phase that advanced the RASCAL system to preliminary design level and validated system design feasibility that had been completed in 2004.

Lessons and technology from Scaled Composites' SpaceShipOne were applied to the supersonic manned aircraft, according to Jacob Lopata, chief executive officer for Space Launch. A lot of the things that Scaled learned during the course of their program directly benefitted 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. Despite DARPA's emphasis on MIPCC turbojet engines for RASCAL, if the technology ran into difficulties the program wouldn'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.

Phase 3 served as the detailed design, construction, test, and demonstration launch phase of the RASCAL program. Flight tests were scheduled to begin in 2006 with final system demonstrations–including the launch of two orbital payloads– in 2008. After takeoff from Mojave Airport in California, the aircraft was to climb to 50,000 feet and then perform a supersonic "zoom" maneuver until it reached 100,000 feet altitude. At that point the engine would shut off and the aircraft would coast on a ballistic trajectory to approximately 180,000 feet, where the rocket would be released. The rocket was to feature a hybrid first stage and a solid-fuel second stage. Among the program's performance goals were 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.

However, The DARPA announced cancellation of the whole RASCAL program on February 2, 2005. The fate of RASCAL had been in doubt for months, particularly after DARPA Director Tony Tether had expressed doubts about the program at a Smallsat conference in Utah in August. DARPA will instead proceed with other efforts to develop low-cost responsive launchers, such as the FALCON program. Space Launch Corporation officials said RASCAL was their main source of revenue, but that they are exploring other opportunities. The fate of the RASCAL program "proves how many technological ideas are often phased out before even leaving a test stage or the R+D money is ciphered off to other areas that prove more viable."

Population: not completed

System Performance:
- Performance to LEO (expected):
- 400 lbs to 270 nm, 28.5° inclination
- Nonlinear Finite Element Analysis
- 250 lbs to 270 nm, 97.1° inclination

MIPCC Powered Vehicle (MPV):
- New aircraft design
- 81 ft span, 89 ft length, 2700 ft2 wing area
- 90,000 lb GTOW
- 4 F100-class engines with LOX/Water MIPCC

Expendable Rocket Vehicle (ERV):
- 2 stage Vehicle, 16,000 lbs at release
- 1st Stage: Hybrid Rocket Motor
- 2nd Stage: Solid Rocket Motor
- Payload volume: 10 ft length, 6 ft diameter

Crew/passengers: unknown

Main sources:
- A demonstration of operationally responsive space launch (.pdf)
- Space Launch Corporation
- SpaceShipOne Lessons Feeding Into RASCAL Aircraft


Final configuration of RASCAL as built by Space Launch.



If the program had reached completion, RASCAL would have
allowed for the insertion of a tactical imaging satellite over
a theater of operations within hours of threat identification.



Comparative sizes of F-15 Eagle, RASCAL and SR-71.

Pioneer Rocketplane's other spaceship designs

In 1996, soon after the setup of the company, Pioneer Rocketplane submitted a bid for the X-34 NASA Research Agreement (NRA) to design and build a subscale reusable hypersonic demonstrator. The commercial vehicle was to be named Pathfinder, a name already used for NASA's Mars probe and high-altitude solar-powered UAV (ironically, an unrelated company by the name of "Pioneer Aerospace" had also been involved with the Mars Pathfinder parachute system). On June 10, NASA chose between nine initial submissions and awarded the X-34 to Orbital Sciences Corporation, the company that failed on the first incarnation of the X-34 NRA, but this didn't keep Pioneer Rocketplane from refining the Pathfinder concept. It had to require no new engine developments, which would postpone the first flight by years. It had to be built by subcontractors to avoid the time and expense of building an in-house manufacturing capability. Most importantly, it had to be able to support the requirements for the new low earth orbit communications satellites. This led to the switch from hydrogen peroxide to liquid oxygen as the preferred oxidizer, and drove an increase in overall size. Version 2.0 of the Pathfinder concept was delivered in 1997 by Conceptual Research Corporation. Pioneer Rocketplane completed a milestone in early September 1998 by completing a full internal systems design review with its subcontractors. The system design review revealed a very well constructed, consistent, "closed" design for Pioneer Rocketplane’s Pathfinder Launch system. A "closed" design represents a good engineering solution we are sure will work when the hardware is actually built.

On June 9, 1997, NASA's Marshall Space Flight Center announced Pioneer Rocketplane as one of four winners in phase one of the Bantam-X program competition. Pioneer Rocketplane; Summa Technology, Inc. (partnered with Lockheed Martin) of Huntsville, Alabama; Aerojet-General Corp. of Sacramento, California; and Universal Space Lines of Newport Beach, California were selected. Total funding for these awards was approximately US$8 million. During the Bantam effort, Pioneer Rocketplane relocated to Vandenburg Air Force Base. It also severed its relationship with Robert Zubrin's Pioneer Astronautics in Lakewood, CO. Co-founder Dr. Robert Zubrin remained President of Pioneer Astronautics, but was no longer affiliated with Pioneer Rocketplane.

Finally came the Pioneer XP (X-Prize), a concept for a four-seat fighter-sized vehicle powered by two jet engines and two rocket engines, enabling it to reach altitudes of 350,000 feet. This concept was developed initially as a contender for the Ansari X Prize. It has applications for passenger travel, as a research and observation platform, and as a promotional and sponsorship opportunity. The XP would operate from ordinary airfields within the well-established rules and practices for aircraft. This concept has evolved into the Rocketplane XP program. In 2001, Rocketplane Limited, Inc. was formed. Pioneer Rocketplane is a part owner of Rocketplane Limited, but ceased operations as an independent company. Rocketplane Limited purchased the intellectual property of Pioneer and put in place an all new management and engineering team to push the development of the Rocketplane XP.