Kosmos 573 (Russian: Космос 573 meaning Cosmos 573) was an unmanned test of the Soyuz without solar arrays in 1973. It did not dock with a space station.[1][2][3]
^Soviet Space Programs, 1976-80: Manned space programs and space life sciences, page 503
^The Soyuz Launch Vehicle: The Two Lives of an Engineering Triumph By Christian Lardier, Stefan Barensky