[5] The device is called the Androgynous Peripheral Docking System (APDS) in the NASA press packet for ASTP.

After these caught, shock absorbers dissipated residual impact energy in the American unit; mechanical attenuators served the same function on the Soviet side.

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.

[5] To Johnson's surprise, Vladimir Syromyatnikov had been working on a variation of NASA's ring and cone concept since the previous October.

[5] In essence, the Soviets had accepted the idea of using a set of intermeshing fingers to guide the two halves of the docking gear from the point of initial contact to capture.

[5] Both groups of engineers planned to retract the active half of the docking gear using an electrically powered winch to reel in a cable.

[5] Johnson, Creasy, and the other engineers in the Spacecraft Design Division had wanted to use four guides because they believed that it provided the best geometry when using hydraulic attenuators.

[5] As Bill Creasy subsequently explained it, the most probable failure situation using hydraulic attenuators would be a leak that would cause one shock absorber to collapse on impact.

[5] A study of various combinations had led the MSC specialists to conclude that four guides and eight shock absorbers was the optimum design.

[5] By the end of the November–December meeting, the two teams had signed a set of minutes outlining the basic concept for a universal androgynous docking system.

[5] The formal statement read, "The design concept includes a ring equipped with guides and capture latches that were located on movable rods which serve as attenuators and retracting actuators, and a docking ring on which are located peripheral mating capture latches with a docking seal.

[5] As long as the requirement for absorbing docking forces was met, each side was free to execute the actual attenuator design as it best saw fit.

[5] In addition, the group concurred on details regarding the alignment pins, spring thrusters (to assist in the separation of the spacecraft at undocking), and electrical connector locations.

[5] To evaluate the docking system concept and to ensure the establishment of compatibility at an early point in the development, the men planned to build a two-fifths-scale test model, the exact details of which would be decided at the next joint meeting.

'"[5] Bill Creasy and several of his colleagues worked with Yevgeniy Gennadiyevich Bobrov at the drafting table to lay out these first Soviet-American engineering drawings.

[11] In April 1972, the Soviets informed NASA that they had chosen to use a Soyuz spacecraft in place of a Salyut space station for cost and technical reasons.

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.

[12] 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.

[12] After the team had a thorough look at the American two-fifths-scale docking system, which helped the designers discuss the operation of the mechanism and decide on refinements, they scheduled joint model tests for December.

[12] Under the direction of Syromyatnikov, the Soviet team had readied their documentation in both English and Russian and had prepared their two-fifths-scale model of the docking system for the joint meeting.

[13] Bushuyev and Lunney called for a thorough re-evaluation of all these issues and advised the group to present their specific recommendations to them in December and January.

APAS was selected for the Shuttle-Mir program and manufactured by Russian company RKK Energiya under a $18 million contract signed in June 1993.

The capture ring aligned them, pulled them together and deployed 12 structural hooks, latching the two systems with an airtight seal.