Polyus

The Polyus spacecraft was a prototype orbital weapons platform designed to destroy Strategic Defense Initiative satellites with a megawatt carbon-dioxide laser, Kaskad. It had a Functional Cargo Block derived from a TKS spacecraft to control its orbit, and it could fire test targets to demonstrate the laser control system. A computer error resulted in spacecraft attempting to perform circularisation burn in a retrograde orientation. As a result, it failed to reach orbit. The station performs several experiments, including several Kaskad laser firing on ground targets and balloons filled gas released by Polyus.