Project 7969 Designs Credit - © Mark Wade

Lockheed's proposal for the Air Force initial manned space project was a 20 degree semiapex angle cone with a hemispherical tip of 30 cm radius. The pilot was in a sitting position facing rearward. The capsule would be launched by an Atlas-Hustler combination into a 480 km orbit for a 4 hour mission.

Tracking would use the Minitrack System and deorbit would be accomplished by retrorocket providing a 60 m/sec braking impulse. Spacecraft attitude control was by rocket thrusters and electrically-powered motors. The spacecraft was automatic and no pilot intervention was required. Maximum G-forces during re-entry were 8 g's and either ablative or beryllium heat shields could be used. In case of booster failure during ascent to orbit the capsule would eject from the booster. The spacecraft had a ballistic coefficient (W/CdA) of 500 kg per square meter. Landing precision was within a 650 x 30 km footprint. It was expected that a first manned orbital flight could be achieved 24 months after a go-ahead at a cost of $ 10-100 million.

Design Life: 5 hours. Typical orbit: 480 km at 28 deg inclination. Length: 4.26 m (13.97 ft). Maximum Diameter: 2.74 m (8.98 ft). Mass: 1,400 kg (3,000 lb). Associated Launch Vehicle: Atlas LV-3A / Agena A.

• Grimwood, James M., Project Mercury: A Chronology, NASA Special Publication-4001.

• Baker, David, The History of Manned Spaceflight, Crown, New York, 1981. The best overview of America's manned space programs up to Skylab. Information and details not available anywhere else. Unfortunately out of print and difficult to locate.