Space research days in the space station, but this achievement was quickly overshadowed since the crew died on reentry to Earth. Salyut 1 was intentionally deorbited six months into orbit since it prematurely ran out of fuel. Skylab was the first American space station. It was 4 times larger than Salut 1. Skylab was launched in May 19, 1973. It rotated through three crews of three during its operational time. Skylab’s experiments confirmed coronal holes and were able to photograph eight solar flares. From 1986 to 2001, Russian space station Mir served as a permanent microgravity research laboratory in which crews conducted
International Space Station leftover USOS hardware and '"Zvezda" 2' as a refuelling depot and service station located at one of the Earth-Moon Lagrange points, L1 or L2. The entire USOS cannot be reused and will be discarded, but some Russian modules are planned to be reused. "Nauka", the Uzlovoy Module, two science power platforms and "Rassvet", launched between 2010 and 2015 and joined to the ROS, may be separated to form OPSEK. "Nauka" will be used in the station, whose main goal is supporting manned deep space exploration. OPSEK will orbit at a higher inclination of 71 degrees, allowing observation to and from