Co-developed by American and Soviet engineers through a series of in-person meetings, letters and teleconferences, APAS-75 was initially planned to be used on an American mission to a
Salyut space station which instead became
Apollo–Soyuz. The device is called the Androgynous Peripheral Docking System (APDS) in the NASA press packet for ASTP. The Americans selected
North American Rockwell to construct seven docking mechanisms (two flight, four test, and one spare). The Soviet Union built five
Soyuz spacecraft that used APAS-75. The first three flew as test systems (
Cosmos 638,
Cosmos 672 and
Soyuz 16). The fourth one was used for the Apollo-Soyuz Test Project,
Soyuz 19 the only Soyuz to actually use the docking system, while the last APAS-75 fitted to
Soyuz 22 was replaced by a camera prior to flight. On the American side the Apollo–Soyuz Docking Module carried one APAS-75 docking collar and one Apollo docking collar.
Development In April 1970 NASA Administrator
Thomas O. Paine suggested, in an informal meeting with Russian academician
Anatoli Blagonravov in New York, that the two nations cooperate on astronaut safety, including compatible docking equipment on space stations and spacecraft to permit rescue operations in space emergencies. Engineer Caldwell Johnson proposed a ring and cone system during a meeting in Moscow during October 1970. Boris N. Petrov rejected the simple adaptation of Apollo and Soyuz as a "space stunt" and had proposed developing a universal docking mechanism, Johnson suggested that the
Manned Spacecraft Center (MSC) draw up a "design specifically adequate to requirements of a particular CSM/Salyut mission, the design being representative only of the fundamental form and function of docking gear satisfying the requirements for compatible docking system for future spacecraft." Larry Ratcliff drew the capture ring and guides on drafting paper, and Robert McElya supplied the details of the structural interface ring, while Bobrov prepared a similar drawing for the structural latches. Final official approval of a joint docking mission came in Moscow on 24 May 1972. U.S. President Nixon and U.S.S.R. Premier
Aleksey N. Kosygin signed the Agreement Concerning Cooperation in the Exploration and Use of Outer Space for Peaceful Purposes, including development of compatible spacecraft docking systems to improve safety of manned space flight and to make joint scientific experiments possible. Some refinements were made in the guides and other parts of the mechanism; as with the other groups, a schedule for the upcoming months was written, indicating documents to be prepared and tests to be conducted. Some of the Americans observed that while the U.S.S.R. mechanism was more complex mechanically than the American one, it was suitable for the mission and "sophisticated" in its execution. The Americans arrived in Moscow on December 6 and worked through December 15. ==APAS-89==