The US-K and US-KMO early warning satellites of the Oko-1 system will be replaced by the next generation of Russian early warning satellites, known as the Tundra or EKS (Edinaya Kosmicheskaya Sistema) series.The EKS was first developed in 2000. 2009 saw the first test launch of the EKS system, which was contracted by the Russian Ministry of Defense to RKK Energiya in 2007. Due to a number of issues, evolving specifications, and a legal dispute, the initial mission was delayed until the end of 2014.According to reports, in the event of a nuclear conflict, the Tundra satellites are also equipped with a secure emergency communications payload.