In February 2009, Gazprom ordered two Yamal-400 type satellites from Thales Alenia Space. The satellites were named Yamal-401 and Yamal-402. Thales Alenia Space was to be responsible for all aspects of the development and building of the satellites. Both satellites were to be based on Spacebus4000C3 satellite buses.[3]
However, in 2010, Gazprom changed their satellite order so that the Yamal-401 satellite would be developed by ISS Reshetnev and be based on their Ekspress-2000 satellite bus. Thales Alenia Space would deliver the payload for Yamal-401 as originally agreed (also, no changes on the payload side of things). There were no changes with the Yamal-402 satellite, with Thales Alenia developing and building the whole satellite as originally planned.[4]
Originally, both Yamal-401 and Yamal-402 were to be launched by Ariane 5, but the launches were changed to Proton-M launch vehicles.
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).