The two nations continued to compete rather than cooperate in space, as the US turned to developing the Space Shuttle and planning the space station, which was dubbed "Freedom". The USSR launched three Almaz military sortie stations from 1973 to 1977, disguised as Salyuts. They followed Salyut with the development of "Mir", the first modular, semi-permanent space station, the construction of which took place from 1986 to 1996. "Mir" orbited at an altitude of , at an orbital inclination of 51.6°. It was occupied for 4,592 days and made a controlled reentry in 2001.