Polyus (spacecraft)
| Mission type | Military technology | 
|---|---|
| Mission duration | Spacecraft failure | 
| Spacecraft properties | |
| Launch mass | 80,000 kilograms (180,000 lb) | 
| Dimensions | 37 m × 4.10 m | 
| Start of mission | |
| Launch date | 15 May 1987 | 
| Rocket | Energia | 
| Launch site | Baikonur 250 | 
| Orbital parameters | |
| Reference system | Geocentric | 
| Regime | Low Earth | 
| Perigee altitude | 280 km (170 mi) | 
| Apogee altitude | 280 km (170 mi) | 
| Inclination | 64° | 
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. It had a Functional Cargo Block derived from a TKS spacecraft to control its orbit and it could launch test targets to demonstrate the fire control system.