Soyuz7K-T No.39 (also named Soyuz 18a or Soyuz 18-1 by some sources and also known as the April 5 Anomaly): 192–3 was an unsuccessful launch of a crewed
learned from the Apollo Soyuz Test Project, Soyuz7K-TM and Military Soyuz. The Soyuz-T was a major upgrade over previous Soyuz spacecraft, sporting solid-state
second generation of the Soyuz spacecraft, the Soyuz7K-T, comprised Soyuz12 through Soyuz 40 (1973–1981). In the wake of the Soyuz 11 tragedy, the spacecraft