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| A Soyuz 16 First Day Cover from "KNIGA", postmarked in Moscow with a hand cancel on March 28, 1975, signed by Anatoly Filipchenko and Nikolai Rukavishnikov. |
Soyuz 16 was launched from Baikonur on December 2, 1974, carrying Soviet cosmonauts Anatoly Filipchenko and Nikolai Rukavishnikov. It was essentially a full-scale dress rehearsal for the Soviet portion of the Apollo-Soyuz Test Project (ASTP), which was scheduled for July 1975.
The spacecraft incorporated modifications that would be needed for the joint U.S.–Soviet mission, including an experimental docking system and changes to its life-support system. The crew also tested the spacecraft under atmospheric conditions designed to make transfers between Soyuz and Apollo safer and faster.
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| A Soyuz 16 US/USSR joint tracking exercise cover, postmarked at Houston, Texas, with a hand cancel on Dec 3, 1974. |
On December 3, 1974, NASA began a joint U.S.–Soviet tracking exercise using Soyuz 16. NASA's Spaceflight Tracking and Data Network (STDN) began tracking the spacecraft shortly after its launch. Data obtained by nine U.S. tracking stations was to be compared with data gathered by Soviet tracking stations. This was intended to verify that the two countries could independently track the spacecraft and exchange the information necessary for the rendezvous and docking operations planned for Apollo-Soyuz.
The simulated docking operations on December 5–7 were successful, and the spacecraft returned to Earth on December 8, 1974. NASA subsequently regarded the mission as an important rehearsal for the Soviet side of Apollo-Soyuz.
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| A Soyuz 16 recovery cover, postmarked in Moscow with a hand cancel on December 8, 1974, signed by Anatoly Filipchenko and Nikolai Rukavishnikov. It features a hand-painted cachet by artist Detlev Van Ravenswaay. |
