Polyus (spacecraft)

The Polyus spacecraft (Russian: Полюс, pole), also known as Polus, Skif-DM, GRAU index 17F19DM, was a prototype Soviet orbital weapons platform designed to destroy Strategic Defense Initiative satellites with a megawatt carbon-dioxide laser.

The Polyus spacecraft was launched 15 May 1987 from Baikonur Cosmodrome Site 250 as part of the first flight of the Energia system,[2] but failed to reach orbit.

This failure was attributed to a faulty inertial guidance system that had not been rigorously tested due to the rushed production schedule.

NPO Energia received orders from the Soviet government to begin research on space-based strike weapons in the mid-1970s.

In the nuclear exchange scenario, the interceptors would destroy the SDI satellites, followed by a so-called "pre-emptive retaliation" large-scale Soviet ICBM launch.

The introduction of the Energia, capable of launching about 95 tonnes into orbit, finally allowed the spacecraft to accommodate the massive laser.

The catastrophic malfunction that led to Skif entering the atmosphere in the same area as Energia's second stage was successfully investigated.