Inmarsat has taken out an option for a launch on an ILS (International Launch Services) Proton rocket in case its plan to launch the Hellas-Sat 3/Europasat on a Falcon Heavy falters. That launch was booked to take place in late 2016, however, SpaceX has now moved this maiden flight to early 2017. The Proton launch option has been provisionally booked for 2017. Inmarsat is managing the launch and operations of the spacecraft which is jointly owned by Hellas-sat (now part of Arabsat) and Inmarsat.
The moves follows a similar move by Viasat. Concerns over the increasing delays to the maiden launch of the SpaceX Falcon Heavy (Falcon 9 Heavy) led Viasat to move its Viasat 2 spacecraft from that flight to Arianespace’s Ariane 5 ECA launcher.