Weird Wings - Lifting Bodies - Martin SV-5D

In the 1960s, the Martin Company developed a lifting body design, the SV-5, in response to the US Air Force Project START (Spacecraft Technology and Advanced Re-entry Tests). A configuration was selected from over a dozen others and developed through scaled-down mockups to the SV-5D. Over 50 subsonic flights were made by Martin's Baltimore Division.

The unmanned test vehicle was to be trial launched by the end of 1966 from Vandenburg Air Force Base, California. It was only 8 ft (2.44 m.) long with a maximum width of 4 ft. (1.22 m.), flat-bottomed with a curved uppr surface, two vertical stabilisers and no wings.

The fuselage shape provided lift, and the SV-5 could change direction whilst gliding in the thin upper air. The mock-up weighed 880-900 lb. (399-408 kg.). Leading edges were of ceramic zirconium graphite and treated molybdenum and columbium. the rest of the body was covered with a silicone ablator.

The USAF's interests in this type were the hopes of a more efficient means of recovering reconnaissance data. In the 1960s this was limited to either television transmission, or physical recovery of film in ballistic capsules, usually air-snatched as they parachuted down near Hawaii.

Normal recovery from the Agena spacecraft of the period required the vehicle to enter a special orbit before triggering re-entry. A manouverable spacecraft could initiate re-entry from a wide range of orbital configurations. As well as easing the recovery operation, the vehicle would also be less vulnerable to anti-satellite missiles.

The carriage of nuclear missiles into space was also a factor. If that was to occur, it was seen as far safer for them to be carried in a vehicle which was easy to control and recover. In theory, a lifting body spacecraft could be launched into standing orbital patrol, to return to its base and land after the emergency period. This would be similar to bombers being sent up on alert, except that the space vehicle could actually overfly its adversary, supposedly as a reminder of its retaliatory power.

A further use was envisaged in the form of manned supply ships for orbital stations. The USAF expected, by 1969, to explore the military potential of space with the Manned Orbiting Laboratory.

The proposed flight plan for the SV-5D was to begin with launch by an Atlas SLV-3 rocket. It would separate from the booster at up to 17,500 mph (28,157 km/h) and steer by a self-contained guidance system and reaction jets until re-entry. A pair of hinged flaps under the tail would control pitch and roll in the atmosphere. When speed had fallen to around Mach 2, a drogue parachute then, at around 45,000 feet, a main parachute. It would then be either air-snatched by a modified C-130 Hercules, or picked up from the sea by recovery ships. Successful testing was hoped to lead to production of a full-sized SV-5R.