Europe’s normally highly dependable rocket, the Ariane 5, experienced an anomaly during its latest launch.Telemetry from the vehicle was lost about nine minutes into its flight from French Guiana, shortly after its upper-stage began the final push for orbit.Uncertainty then followed as controllers tried to determine the status of Ariane and the satellites it was carrying.Eventually, though, radio signals from the spacecraft were picked up.It seems the rocket did do its job – but beyond the sight of controllers on the ground.Arianespace, the company that operates the Ariane 5 from the Kourou spaceport in French Guiana, issued the following statement late on Thursday, local time: “The launcher’s liftoff took place… at 7:20pm,” it read. “A few seconds after ignition of the upper-stage, the second tracking station located in Natal, Brazil, did not acquire the launcher telemetry. “This lack of telemetry lasted throughout the rest of powered flight.”Subsequently, both satellites were confirmed separated, acquired and they are on orbit. [The two satellites] are communicating with their respective control centres. Both missions are continuing.”One satellite is owned by Luxembourg-based operator SES, the other belongs to Abu Dhabi-based Yahsat. They are both telecommunications platforms.The SES satellite, called SES-14, was manufactured in the UK by Airbus at its Portsmouth and Stevenage plants.What is not yet completely clear is if the two satellites separated from the upper-stage of the Ariane in the right part of the sky.If they were released at a less than optimal altitude, this could make it difficult for them to reach their final, planned stations some 36,000km above the planet.The SES satellite does however have electric propulsion. This is a slow but very efficient means of raising the orbit of the spacecraft and would give it a very good chance of recovering any orbital shortfall. Yahsat’s spacecraft, Al Yah-3, on the other hand, has a more conventional chemical propulsion system, which could make it harder to reach its station if the separation from the rocket was significantly off mark.
What happened during Thursday’s flight was a highly unusual occurrence.Although, famously, the Ariane 5 failed on its very first outing in 1996, it has since set a benchmark for reliability in the launcher business. Before this flight it had gone to space 82 times on the trot without mishap.An inquiry will try to determine what exactly went wrong and assess whether any changes are required to the vehicle’s design to ensure there is no repeat telemetry loss in future.On the current calendar, the Ariane 5 is due to make up to six more launches this year. Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos
Source: BBC Bucks