Okno (Russian: Окно meaning window) is a Russian space surveillance station located in Nurak in Tajikistan . It is run by the Russian Aerospace Defence Forces and is part of the Centre for Outer Space Monitoring . It is located 2,216 metres (7,270 ft) above sea level in the Sanglok mountains, an area with clear night skies.

The facility consists of a number of telescopes in domes and is similar to the US GEODSS system. It is designed for the detection and analysis of space objects such as satellites . The designers were awarded a Russian state prize for science and technology in 2004.

The Okno facility was started by the Soviet Union in 1979. All construction stopped in 1992 due to the civil war in Tajikistan and the centre started test operations in 1999 and combat duty in 2004 . Ownership of the complex was transferred from Tajikistan to Russia in 2004 in return for the writing off of $242 million USD of Tajikistan's $299 million USD debt to Russia .

When it was built built it was believed by some in the west to be a military anti-satellite laser facility for rather than one for optical tracking. In 1987 John E. Pike of the Federation of American Scientists was quoted as saying "Whether or not this facility will be capable of shooting down satellites or 'Star Wars,' it most certainly is developing the kind of technology that would eventually be able to do so."