Russia launched the Cosmos 2546 satellite into a highly elliptical Earth orbit at 0731 GMT using a Soyuz 2-1B/Fregat M launch vehicle from Pad 43/4 at the Plesetsk Cosmodrome in Northern Russia. Cosmos 2546 is also known as Tundra 4, Kupol No. 4 and EKS 4. The satellite will be placed into the EKS constellation to provide Missile Early Warning to the Russian Ministry of Defence.

Molniya and Tundra orbits are similar but have different periods. Courtesy: Marcom/Marintek/Sintef

Update on 23 May 2020: Cosmos 2546 confirmed as successfully launched into Molniya style 38,508 x 1656 km orbit at 63.8 degrees inclination.