Short answers, pulled from the story.
Salyut 1 was the world's first space station, launched by the Soviet Union on the 19th of April 1971 into low Earth orbit. Officially designated DOS-1 (Durable Orbital Station 1), it was adapted from an Almaz military airframe and measured 15.8 meters in length with 90 cubic meters of habitable space.
The Soyuz 11 crew, Georgy Dobrovolsky, Viktor Patsayev, and Vladislav Volkov, died of asphyxia when a pressure relief valve malfunctioned during reentry on the 29th of June 1971, allowing the cabin atmosphere to escape. None of the three were wearing pressure suits. They are the first and, as of 2026, only humans to have died above the Karman line.
The Soyuz 11 crew spent 23 days aboard Salyut 1, completing 362 orbits. Their stay marked the first time in spaceflight history that a space station had been occupied, and it set a new record for time spent in space.
Soyuz 10, carrying Vladimir Shatalov, Aleksei Yeliseyev, and Nikolai Rukavishnikov, soft-docked with Salyut 1 on the 24th of April 1971 but failed to achieve a hard dock due to technical malfunctions. The crew was unable to enter the station and returned to Earth the same day after 5.5 hours docked.
The Orion 1 Space Observatory was an astrophysical instrument designed by Grigor Gurzadyan of the Byurakan Observatory in Armenia and installed inside Salyut 1. It captured ultraviolet spectrograms of the stars Vega and Beta Centauri in a wavelength range of 2000 to 3800 angstroms. Viktor Patsayev operated it, becoming the first person to use a telescope outside of Earth's atmosphere.
Salyut 1 reentered Earth's atmosphere and burned up over the Pacific Ocean on the 11th of October 1971, after 175 days in orbit. The station was deliberately deorbited because it ran out of fuel before a redesigned Soyuz spacecraft could be sent to it.