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| An Apollo-Soyuz Test Project launch cover from "KNIGA", postmarked in Moscow with a hand cancel on July 15, 1975, signed by both the US and Russian crew members: Thomas Stafford, Vance Brand, Donald Slayton, Alexei Leonov and Valeri Kubasov. |
The Apollo-Soyuz Test Project (ASTP) was the first crewed space mission carried out jointly by the United States and the Soviet Union. It was a remarkable event in the middle of the Cold War, bringing together two countries that had been competing in space for nearly two decades. NASA describes it as the first international partnership in human spaceflight.
On July 15, 1975, the two spacecraft launched from opposite sides of the world - Soyuz 19 launched from the Baikonur Cosmodrome at 8:20 a.m. EDT with Alexei Leonov and Valeri Kubasov, the American Apollo spacecraft launched from Kennedy Space Center at 3:50 p.m. EDT aboard a Saturn IB, carrying Thomas Stafford, Vance Brand and Donald Slayton.
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| An Apollo-Soyuz Test Project launch cover from "KNIGA", postmarked in Moscow with a hand cancel on July 15, 1975, signed by Russian crew members: Alexei Leonov and Valeri Kubasov. |
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| An Apollo-Soyuz Test Project launch cover postmarked at Star City with a hand cancel on July 15, 1975, signed by the US backup crew: Alan Bean, Jack Lousma and Ronald Evans. |
After two days of orbital maneuvering, Apollo and Soyuz met and docked on July 17, 1975. Stafford and Leonov then exchanged the famous first international handshake in space. The spacecraft remained together for roughly two days while the five astronauts and cosmonauts carried out joint experiments, exchanged visits, and demonstrated the new international docking system.
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| An Apollo-Soyuz Test Project link-up cover postmarked at Star City with a hand cancel on July 17, 1975. |
The two spacecraft remained connected for roughly two days. The five crewmen moved between the spacecraft, conducted joint experiments, exchanged gifts, ate together, conducted television broadcasts and performed a series of joint activities.
On July 19, the joint phase came to an end. The first undocking occurred at about 8:03 a.m. EDT. Apollo backed away from Soyuz and positioned itself between Soyuz and the Sun, creating an artificial solar eclipse. Leonov and Kubasov photographed the solar corona from Soyuz.
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| An Apollo-Soyuz Test Project undocking cover postmarked in Kaluga with a hand cancel on July 19, 1975. |
The spacecraft then performed another docking exercise. Apollo redocked with Soyuz, this time with Soyuz's docking system active. After remaining together for about three hours, the spacecraft performed the final undocking at 11:26 a.m. EDT. Apollo then moved away and conducted the ultraviolet atmospheric absorption experiment, while also photographing Soyuz at close range.
After the final separation, the two spacecraft continued independently. Soyuz 19 remained in orbit until July 21, when Leonov and Kubasov returned to Earth in Kazakhstan. Apollo continued flying for several more days, conducting additional experiments, before Stafford, Brand and Slayton splashed down in the Pacific on July 24.
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| Photo: Alexei Leonov displays his "Space Age Solar Eclipse" painting at a press conference. |
