WHITE SANDS MISSILE RANGE, N.M., July 7, 1995 -- The Delta Clipper Experimental launch vehicle's (DC-X) successful completion of an aggressive series of flight tests this week builds on it's successes by beginning the next phase of a program in which it will receive advanced technology components.
Light weight, high strength materials will be used in DC-XA's new liquid oxygen tank fabricated from aluminum lithium and liquid hydrogen tank constructed from graphite composite.
These components will be integrated into the McDonnell Douglas-built reusable rocket and Huntington Beach, Calif. In 1996, the DC-X will be returned to White Sands
Missile Range in January as the DC-XA, and a new series of flight tests will resume in April under a series of agreements awarded by NASA. The tests will continue to demonstrate the feasibility of a reusable rocket which has aircraft-like operability and maintainability.
The Delta Clipper has demonstrated fast turnaround by being readied for flight in seven days. In addition, the reusable launch vehicle's engines were test fired twice within eight hours.
The DC-X also demonstrated its aircraft-like operability by being flown by a three member crew. Normal maintenance of the experimental rocket was accomplished by seven technicians.
Other firsts for the DC-X included the use of reaction control thrusters fueled by gaseous oxygen and hydrogen used as an additional flight control for the first time during a recent flight. Global positioning satellite-aided data was also used by the vehicle's internal navigation system. Attitude control of the DC-X demonstrated the blending of differential throttling with engine gimbaling.
On it's eighth and last flight of the recently completed tests, the DC-X pointed its nose 10 degrees below the horizon and rotated through a 180 degree angle of attack sweep for a base-first landing using its engines to brake. The maneuver would be executed by a vertical-landing rocket after reentering the Earth's atmosphere.
"Completion of this critical rotation maneuver and continued reduction of time required to maintain and prepare the DC-X for flights, shows that vertical-takeoff, vertical landing technology is feasible," said Dave Schweikle, program director for McDonnell Douglas Aerospace.
Anomalous radar altimeter signals biased the DC-X's guidance system, resulting in a harder than planned landing. A more rapid than planned descent velocity during the landing phase of the successful flight test caused compression of energy-absorbing honeycomb material in the landing gear. However, the flight accomplished its goal by demonstrating the rotation maneuver. Initial review of the vehicle and ground support systems indicated that the DC-X could have accomplished the rapid turnaround. A rapid turnaround demonstration will be performed in the DC-XA test series with a goal to ready the launch vehicle within 72 hours between flights, noted Lt. Col. Jess Sponable, Advanced Spacelift Technology Office program manager for U.S. Air Force Phillips Laboratory at Kirtland Air Force Base in New Mexico.
At the conclusion of the flight, the DC-X was officially turned over to NASA. Lt. Col. Jess Sponable presented a plaque attesting to the turnover to NASA Program Manager Dan Dumbacher. McDonnell Douglas will integrate key advanced technology components into the vehicle under a contract with NASA. The upgraded vehicle will be called the DC-XA.
The DC-X was built by McDonnell Douglas in California and is managed by the Phillips Laboratory. Flight test support is provided by the Air Force Space and Missile Systems Center, Space and Missile Test and Evaluation Directorate.
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