The withdrawal of GSAT-11 from its planned Ariane 5 ECA launch (with Azerspace 2/Intelsat 38) caused a major interruption in Arianespace’s launch schedule. The heaviest satellite produced by ISRO at 5725kg, GSAT-11 arrived at the Kourou launch site in French Guiana to some fanfare on 30 March, ready for its launch. However, the satellite was soon put on an aircraft back to India on 23 April as it was deemed that extra checks were needed. The cause was concern over the satellites power system redundancy following the post launch failure of GSAT 6A after an apparent failure in its power system in late March.
As a result of GSAT-11’s withdrawal, the May launch of that satellite and Azerspace 2/Intelsat 38 was cancelled and is now thought unlikely to take place until late summer – although ISRO hopes its testing will be over by 17 May. Theoretically, a flight in late June/early July might be possible if it can be returned in time, but it would be a rush, and an August flight is more likely. For the time being, the early summer looks surprisingly bare in the Ariane 5 launch schedule with the next launch (of an Ariane 5 ES) on 25 July carrying four Galileo satellites. Following this the six metric ton Hellas-Sat 4/Saudigeosat-1 could theoretically be launched in August, although it would ideally need a smaller satellite to pair with it. The delayed 3.5 metric ton Azerspace 2/Intelsat 38 would fit the bill, although it is more likely that the GSAT-11 will return to fly with it. Complicating matters in respect of the Kourou range is the Vega launch of the ADM Aeolus wind monitoring mission which is planned to take place on 21 August.