The first was Almaz-T which launched on 29 October 1986. The Proton rocket in launched on failed, and was destroyed by its safety system. The next was Almaz-T2, which went to space on 25 July 1987 and stayed in space for two years. The third was Almaz-1 which launched on 3 March 1991 and stayed in space for 18 months. A fourth satellite (Almaz-2) was built but never sent to space.