The Apollo-Soyuz Test Project marked many firsts, including the first internationally manned
mission, the first rendezvous between two manned spacecraft and the first time Americans and
Russians floated into each others' spacecraft.
ASTP was part of an agreement signed by U.S. President Nixon and Soviet Union Premier
Kosygin on May 24, 1972. The mission allowed astronauts to test the new U.S. docking module
and opened the door for future internationally manned missions and possible international space
Existing Apollo and Soyuz spacecraft were used. The Apollo 18 spacecraft was nearly identical to
the one that orbited the moon and later delivered astronauts to the Skylab space station. The
Soyuz spacecraft has been the primary Soviet space vehicle for manned spaceflight since it was
introduced in 1967.
NASA designed the docking module to serve as an airlock and corridor between the two
Soyuz 19 launched from Baikonur Cosmodrome on July 15, 1975 carrying cosmonauts Alexei
Leonov and Valery Kubasov. Apollo 18 launched seven and a half hours later using a Saturn IVB
launch vehicle. It took off from Kennedy Space Center, Fla. carrying astronauts Tom Stafford,
Deke Slayton and Vance Brand.
These two stamps share the same design as two Soviet stamps issued on the same date. The top design is American, the lower is Soviet.
Issue Date: July 15, 1975