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1.9 ASTP Soyuz (1974-1976) ASTP Soyuz (figure 1-21) was the Soyuz Ferry modified to carry out the specialized mission of docking with a U.S. Apollo spacecraft in Earth orbit.

Figure 1-21. Apollo-Soyuz Test Project (ASTP) Soyuz. The APAS-75 docking unit is located at left.

1.9.1 ASTP Soyuz Specifications

Launch weight (Soyuz 19) ....................... 6680 kg

Launch weight (Soyuz 22) ....................... 6510 kg

Length (Soyuz 19) .................................. 7.48 m

Length (Soyuz 22) .................................. 7.6 m

Span across solar arrays ......................... 8.37 m

Diameter of habitable modules ................. 2.2 m

Maximum diameter ................................. 2.72 m

Habitable volume .................................... about 10 m³

Number of crew ...................................... 2

1.9.2 ASTP Soyuz Notable Features Soyuz 22, the backup to the Soyuz 19 ASTP Soyuz which docked with Apollo, did not incorporate all these notable features. Some may also have been absent from the Cosmos 638 and Cosmos 672 ASTP Soyuz spacecraft; nonetheless, the ASTP Soyuz was generally associated with the following notable features:

Advanced solar arrays. Modified life support systems capable of supporting four crew. This was necessary for Apollo crew visits to Soyuz, and also in the event that Soyuz had to pull away from Apollo with two Americans aboard. APAS-75 androgynous docking unit (figure 1-22) compatible with the unit on the docking module.

U. S. and Soviet engineers jointly developed the system for ASTP. APAS is the acronym for the English translation, “androgynous peripheral assembly system,” and the number is the year of its first use in space. Modified coloration for compatibility with Apollo rendezvous sensors. Improved control systems.