THE MCDONNELL Douglas Delta Clipper experimental launch vehicle (DC-X) had its operating envelope expanded to an altitude of 5,700ft (1,740m) and 70° angle-of-attack (AoA) during the latest test flight at the US Army's White Sands Missile Range, New Mexico.

The DC-X flights, are managed by the US Air Force Phillips Laboratory, at nearby Kirtland AFB, in support of the NASA re-useable-launch-vehicle programme. An upgraded vehicle, the DC-XA, is being prepared for test flights in 1996, using data collected during the current series of flights. These will culminate later this year with high AoA manoeuvres of up to 180°, to simulate the rotation manoeuvre, which a single-stage-to-orbit vehicle would need to perform for a vertical landing.

During the 2min 12s flight, the DC-X traveled almost 600m downrange and flew sideways at 6,600ft/min (33.5m/s) back to the landing site. The launch vehicle beat its previous altitude by more than 1,300ft, before descending base-first to land at just over 11,800ft/min, compared to 8,600ft/min on the earlier flight.

The DC-X was being taken through the more extreme manoeuvres in preparation for its eighth flight, when MDC plans to rotate the vehicle. The test flight also demonstrated the first use of four reaction-control gaseous oxygen-hydrogen thrusters, which improve precise control of the DC-X.

Further tests of other flight controls were also conducted, including engine throttling and testing of control flaps located on the side of the vehicle.

Source: Flight International