The correspondence between Kennedy and Khrushchev regarding the joint exploration of space led to a 1965 agreement between the two countries to publish a joint review of space biology and medicine. However, no more cooperative ventures regarding space arose until 1969. Thomas Paine, the Administrator of NASA at the time, believed that the relationship between the USA and the USSR would improve if the two countries were to establish a cooperative space program. And with the United States so far ahead in the race to the moon, a cooperative mission would not give the USSR any advantage in the race. In fact, Paine believed, the USSR might agree to such a venture, because it would give the Soviets an image of technological parity by working with the United States, which had been the only nation to send men in an orbit around the moon.
The following summary of the interchange between the United States and the Soviet Union leading up to the Apollo Soyuz Test Project is taken directly from a NASA News release dated June 10, 1975:
In 1969, NASA Administrator Dr. Thomas O. Paine wrote to Soviet Academy President M. V. Keldysh and Academician Blagonravov, inviting new initiatives in space cooperation, in general scientific fields, and in rendezvous and docking of manned spacecraft.
In October 1970 talks related to the possibility of the U.S. and U.S.S.R. each designing a manned spacecraft with a compatible docking mechanism were held in Moscow. These discussions were resumed in January 1971. Later, joint working groups were established and technical understandings required for design of these systems were developed. In April 1972, the necessary management and operational understandings were established to warrant a government-level agreement to a joint test docking mission.
Broader discussions on cooperation in space science and applications took place in January 1971 in Moscow. As a result of these talks, an agreement was reached which provided for:
- Exchange of lunar samples obtained in Apollo and Luna programs;
- Exchange of weather satellite data between the United States National Oceanic and Atmospheric Administration (NOAA) and the Soviet Hydrometeorological Service;
- Coordination of networks of meteorological rocket sounding along selected meridianal lines;
- Development of a coordinated program to utilize space and Earth resources survey techniques to inves tigate the natural environment in areas of common interest;
- Joint consideration of the most important scientific objectives for exchange of results from investigation of near-Earth space, the Moon, and the planets; and
- Exchange of detailed medical information of man's reaction to the space environment.
ASTP was formally provided for in the U.S.-U.S.S.R. Agreement Concerning Cooperation in the Exploration and Use of Outer Space signed by President Richard Nixon and Soviet Chairman Aleksey Kosygin in Moscow May 24, 1972. This agreement also pledged both countries to fulfill the NASA-Soviet Academy of Sciences agreement of January 1971.
The 1972 Agreement Concerning Cooperation in the Exploration and Use of Outer Space was part of the Strategic Arms Limitation Talks (SALT I), a series of negotiations between the United States and the Soviet Union primarily intended to limit some of their most important armaments. These talks were part of Nixon's detente, an attempt to ease tensions between the US and the USSR. The Apollo Soyuz Test Project was largely made in an attempt to ease the competition of the space race, and, triumphantly, it worked.