Polyus (Spacecraft)

Polyus, also known as Skif-DM with GRAU index 17F19DM, was a prototype Soviet orbital weapons platform designed to destroy satellites of the American Strategic Defense Initiative with a one-megawatt carbon-dioxide laser. A Functional Cargo Block derived from the TKS spacecraft controlled its orbit, and it could launch test targets to demonstrate its fire control system. NPO Energia was ordered in the mid-1970s to research space-based strike weapons, and the spacecraft was rushed through development between September 1985 and September 1986 so that it could serve as the payload of the first Energia launch. It lifted off on 15 May 1987 from Baikonur Site 250 but failed to reach orbit: it was launched upside down and was meant to turn 180 degrees after separation, yet a faulty inertial guidance system let it spin a full 360 degrees, the engine fired against its motion and the craft burned up over the South Pacific. It was 37 metres long, 4.10 metres across and had a mass of 80,000 kilograms. Parts of its hardware were reused in Mir and International Space Station modules.