Martin X-23 PRIME

The Martin- Marietta X -23 was a small supporting hull reentry aircraft that has been tested by the United States Air Force in the 60s. The X -23 was designed primarily to investigate the effects of aircraft maneuvers during reentry, this included flight maneuvers up to a deviation of 1143 km from the ballistic trajectory a.


The X -23A, also known as SV - 5D, was developed under the project PRIME (Precision Recovery Including Maneuvering Entry), which in turn was part of the three- START ( Spacecraft Technology And Advanced Entry) program. In these programs, the shape of the SV -5 buoyant body both at very high speeds reentry ( X 23A), as well as at low landing speeds (X -24A ) was tested. As a launcher, its SLV -3 Atlas was used in the experiments that were started from the premises SLC -3E at Vandenberg Air Force Base.


Each X 23 is made from a 2014 T6 alloy of titanium and beryllium, stainless steel and aluminum. The complete system was protected by a model developed by Martin Marietta heat shield, which was 20 to 70 mm thick. The nose consisted of a carbon - phenolic resin.

The attitude was 30 cm long bottom flap, top flap and rudder controls. A nitrogen gas control system has been used outside the Earth's atmosphere. At Mach 2, a drogue parachute has been opened, in order to brake the descent of the X- 23. Later, a special 16.4 m parachute was opened, which was obtained from a modified Lockheed C -130.

Flight tests

The first X -23 was launched on 21 December 1966 by Vandenberg from an Atlas rocket. During the mission, the X -23 took a low orbit. Upon returning to Earth, the first parachute opened at an altitude of 30.43 km, however, the main parachute could not be opened successfully, so the X -23 crashed into the Pacific Ocean.

The second flight was launched on 5 March 1967 and reached during re-entry a "reach" ( deviation from the ballistic trajectory ) of 1053 km, and the control at supersonic speed. Some " stringers " on the main parachute were not separated, which again prevented a successful recovery of the X -23.

The third and last flight of an X -23 was carried out on 19 April 1967. This time, all systems worked perfectly and the X -23 was recovered after landing. After a thorough investigation it was found that the X -23 would be ready to use again, but no further flight, it was done with her.


The third X -23 is now on display at Wright - Patterson Air Force Base. The whereabouts of the fourth built the float, which never flew, nothing was known.

General data