Cosmos 2546

The Tundra or EKS (Edinaya Kosmicheskaya Sistema) series of satellites is the next generation of Russian early warning satellites to replace the US-K and US-KMO early warning satellites of the Oko-1 system. The development of the EKS started in 2000. The Russian Ministry of Defence awarded in 2007 a contract for the EKS system to RKK Energiya with a first test launch planned in 2009. Several problems, changing requirements and a court case led to long delays, postponing the first mission to the end of 2014. Reportedly the Tundra satellites carry also a secure emergency communications payload to be used in case of a nuclear war.