Soyuz 8
The Soviet Union launches Soyuz 8, intended to be the passive partner in a space rendezvous and docking with Soyuz 7 (launched the previous day), as the already-launched Soyuz 6 films the docking. When the rendezvous radar gear aboard all three Soyuz vehicles fail to function properly, the docking is aborted; the only history made by the near-simultaneous trio of Soyuz craft is the largest number of humans in orbit at the same time to date (seven). Cosmonauts Vladimir Shatalov and Alexei Yeliseyev – both veterans of the docking missions of Soyuz 4 and 5 earlier in the year – return to Earth after nearly five days in space.