|Volume 4,||Number 1||March/April 1996|
In July 1995, the U.S. Air Force transferred to NASA's Office of Space Access and Technology the unpiloted, single-stage rocket known as the Delta Clipper-Experimental (DC-X), for use in NASA's Reusable Launch Vehicle (RLV) technology program. The goal of the RLV program is to dramatically reduce the cost of access to space as compared to current launch systems.
After successfully completing a series of eight test flights, the DC-X rocket was transferred to NASA. The rocket, which NASA renamed the Delta Clipper-Experimental Advanced (DC-XA), will be modified with technology components to demonstrate their applicability to the X-33 and X-34 RLVs now under development by NASA and its aerospace industry partners. Technology components being integrated into the DC-XA vehicle are: a composite (graphite-epoxy) liquid hydrogen tank; an aluminum-lithium alloy liquid oxygen tank constructed in Russia; a composite intertank primary structure; and an auxiliary propulsion system consisting of a composite liquid hydrogen feedline, a composite liquid hydrogen valve, and a liquid-to-gas conversion system in the flight reaction control system.
"We plan to take these new technology components and test them in a real-world environment," said NASA's DC-XA project manager Dan Dumbacher of NASA's Marshall Space Flight Center in Huntsville, Alabama. Marshall is the host center for NASA's RLV technology program. "We will demonstrate what it takes to support and operate these technology components and show their performance in the real-world operating conditions. What we learn by testing the DC-XA will enable us to better understand the technology integration issues ahead of us in the X-33 and X-34 programs. This will save these programs both time and money."
In December 1995, the lightweight composite hydrogen tank was the first component to successfully complete testing. The ability to use composites is important to the development of a single-stage-to-orbit RLV because of the weight reduction they provide. "This is the largest composite hydrogen tank ever to successfully survive flight operating conditions. It demonstrates that composite tanks can be used for other reusable launch vehicles in the future," said Dumbacher.
McDonnell Douglas is responsible for developing the technology components, integrating them into the DC-XA vehicle and conducting the ground and flight test series. This work is being performed under a cooperative agreement, as an example of a new way of doing business. Under this arrangement, McDonnell Douglas and NASA have agreed to a fixed government contribution to complete the work, and McDonnell Douglas has provided corporate contributions of in-kind material and internal research and development (IRAD) funds to share the costs. This arrangement also puts McDonnell Douglas and NASA in partnership roles without the typical government oversight. Hardware costs for the DC-XA project are $20 million, and integration costs are $30 million.
The DC-XA program has been extremely successful in maintaining its fast-paced schedule in spite of the technology development challenges experienced during the design and fabrication of the components. The liquid oxygen tank and composite intertank have been delivered to McDonnell Douglas in Huntington Beach, California, for vehicle integration. The auxiliary propulsion system is undergoing integration testing at Aerojet in Sacramento, California, prior to vehicle integration.
The DC-XA will begin extensive ground and flight testing, providing valuable information to the X-33 and X-34 programs, in May 1996 at White Sands, New Mexico. Phillips Laboratory at Kirtland Air Force Base in Albuquerque, New Mexico, will act as NASA's deputy for flight test and operations for the DC-XA. NASA field centers supporting the DC-XA include Marshall, Langley Research Center in Hampton, Virginia, and Dryden Flight Research Center in Edwards, California.
Information is available through the RLV Home Page on the World Wide Web at: http://rlv.msfc.nasa.gov/
The DC-XA is a single-stage-to orbit launch vehicle concept, whose development is geared to significantly reduce launch costs. It will provide a test bed for NASA RLV technology.
For more information, contact Dan Dumbacher at the Marshall Space Flight Center. Phone: 205/544-1289, E-Mail Dan.Dumbacher@msfc.nasa.gov Please mention that you read about it in Innovation.