Having been delayed by the weather and by the need to change out an inertial measurement unit on the rocket, at 2102 GMT on 25 April 2016 a Soyuz ST-A (Fregat M) finally launched from the Sinnamary launch site near Kourou in French Guiana.
The main payload aboard was the Sentinel-1B radar satellite which was being launched on behalf of the European Space Agency (ESA).
Also on the manifest was the MICROSCOPE satellite being launched for the French Space Agency CNES. It is a science satellite carrying test masses made out of different materials to test out the equivalence principle described by Albert Einstein. The spacecraft will use Field Emission Electric Propulsion (FEEP) Thrusters to create a ‘drag deceleration free’ free fall testing environment.
Three 1U cubesats were also on the flight: OUFTI-1 for the University of Liege which is to test D-Star amateur radio protocols for digital radio communications, AAUSAT-4 for Aalborg University in Denmark which is to carry a student-built AIS (Automated Identification System) receiver, and E-St@r-II for the Politechnic University of Turin which is to demonstrate a system to detect and control spacecraft’s attitude using measurements of the Earth’s magnetic field.
The NORSAT-1 spacecraft, a test satellite carrying a solar radiation monitor and VHF AIS system, made by the Norwegian Space Center (NSC) was intended to be part of the launch however, a few days before the launch it was pulled from the manifest due to a faulty holding bracket supplied by Arianespace. Launch alternatives are being looked into by both Arianespace and the NSC.