Space stations are large structures in space where astronauts live and work Since the 1970s humans have built several space stations that orbit Earth Many countries have sent astronauts to live in these stations for days weeks or even months These longer stays allow scientists to study how living in space affects the human body The Soviet Union built the first space station in 1971 Known as Salyut 1 it launched into space on April 19 Two days later a Soyuz space shuttle carried three cosmonauts into space The shuttle docked or connected with Salyut 1 However the cosmonauts could not open the station's hatch so they had to return to Earth Another Soyuz shuttle carried a new crew to Salyut 1 in June 1971 This time the cosmonauts were able to open the hatch and enter the station They spent three weeks in space While they were
An artist's illustration of a Soyuz shuttle left preparing to dock with Salyut 1 right on the space station the cosmonauts orbited Earth 383 times However tragedy struck during their return flight An air leak depressurized the shuttle and all three died cosmonauts
Salyut 1 orbited Earth for a total of 175 days Then Soviet scientists fired the empty space station's engines pushing it into a lower orbit From there Salyut 1 fell toward Earth and splashed into the Pacific Ocean Despite the deaths of the three cosmonauts the Soviet Union sent six more Salyut stations into space Each new space station used an improved design But all of the stations stayed in a fairly low orbit around Earth This low orbit made each station easy to reach with space shuttles However it also meant the station was still inside Earth's upper atmosphere As the space station moved through the atmosphere drag lowered the station's orbit The station needed booster rockets to move it back up to a slightly higher orbit Otherwise the station would fall back Earth to
LI H UOMIOITATE Soyuz shuttles continued to carry passengers and cargo to several other space stations Salyut 7 was the last space station of its kind The last crew visited Salyut 7 in 1986 The Soviet Union's government struggled in the late 1980s It could not afford any more repairs or shuttles Left unused for several years Salyut 7 fell to Earth in 1991 Most of the station burned up as it reentered Earth's atmosphere However the technology used to build it paved the way for future space stations
