Apollo-Soyuz Command Module

Apollo-ASTP launch. Photo courtesy of NASA.

...this Apollo command module was flown by American astronauts Tom Stafford, Deke Slayton and Vance Brand to rendezvous with a Russian Soyuz spacecraft parked in orbit around the Earth. Although built to fly to the moon as Apollo 18 its mission was changed when funding was cut for the Apollo program. The Science Center’s Apollo Space Capsule is on loan from the Smithsonian Institution, National Air and Space Museum.

Apollo-ASTP Specs
Launch date: July 15, 1975


Crew: The entire ASTP crew included American astronauts Thomas Stafford (standing, left); Donald K. “Deke” Slayton (seated, left) and Vance D. Brand (seated, center) and Russian cosmonauts Aleksey A. Leonov (standing, right) and Valeriy N. Kubasov (seated, right)

Initial docking with Soyuz: July 17, 1975
Altitude at time of docking: 222 km (138 miles)
Duration of initial docking: 44 hours
Final undocking with Soyuz: July 19, 1975
Apollo Command Module splashdown: July 24, 1975
Duration of Apollo flight: 9 days, 1 hour, 28 minutes, 24 seconds
Number of orbits for Apollo Command Module: 148
Distance traveled for Apollo Command Module: 5,990,000 kilometers (3,700,000 miles)
Launch vehicle: Saturn 1B

The Apollo ASTP Command Module and the Russian Soyuz Spacecraft in Earth orbit. Photo courtesy of NASA.

Crew transfer between Apollo and Soyuz: The atmospheric pressure and gas composition inside the Apollo command module differed from that used inside the Russian Soyuz spacecraft. The American spacecraft used a pure oxygen environment at one-third atmospheric pressure (5 psi). The Soyuz used an 80-percent nitrogen 20-percent oxygen environment at a pressure of one full atmosphere (14.7 psi). In order to allow safe transfer between vehicles the Russian and American engineering teams jointly created a docking module that was inserted between the Apollo and Soyuz spacecraft. Prior to docking with the Apollo command module (that was linked to the docking module) the Russian crew lowered their cabin atmospheric pressure from a full atmosphere to two-thirds atmosphere. After docking with the Soyuz, the American crew transferred from the Apollo spacecraft into the docking module and closed the hatch behind them. They added nitrogen to the pure oxygen environment which raised the pressure inside the docking module from one-third atmosphere to two-thirds atmosphere and resulted in a gaseous composition that matched the Russian Soyuz spacecraft. The astronauts could then safely open the hatch between the docking module and the Soyuz.

Manufacturer: North American Aviation, Inc. which became North American Rockwell Corporation in September 1967 and then Rockwell International Corporation in February 1973.