Advanced Television

Arianespace avoids disaster

January 29, 2018

By Chris Forrester

Arianespace Group’s phenomenal Ariane-5 rocket has been a remarkable success for so long that it is a major surprise when something goes awry. The last failure was back in December 2002, when a Eutelsat (Hot Bird 7) was lost along with a scientific satellite. Since then, Ariane has managed 82 perfectly successful missions.

A lift-off on Thursday evening (January 25) from its French Guiana site seemed to go well initially and for viewers to its web-cast, but the engineers and technicians sat in the Jupiter 2 Control Room were quickly aware that there were two problems: there was inadequate telemetry data flowing from the rocket following the ignition sequence, and this lack of telemetry lasted throughout the flight.

It now appears that the rocket’s initial launch trajectory may have been off. A local observer in French Guiana simply said that launches normally never fly directly over a local beach! Closer examination of the official Space Centre live graphic also appears to experts to show the rocket’s flight path as deviating from that which was intended. Later on Jan 26th Arianespace confirmed the “trajectory deviation”.

Then and to make matters seem much worse, the rocket failed to correctly deploy its cargo (‘orbit injection’) of two satellites causing some early reports to suggest that the satellites had been lost.  Dr Mohamed Nasser Al Ahbabi, director general of the UAE Space Agency and members of his team were on hand to monitor proceedings – and explained that Al Yah 3 had not been correctly launched.

The first deployment (SES-14) was scheduled for 27 minutes after launch, and the second passenger, Al Yah-3 some eight minutes later.

Some 20 further minutes passed before Arianespace CEO Stephane Israel appeared in the Jupiter control room to explain that contact with the rocket’s upper stage had been lost, and that there had been no contact with the satellites. “We need now some time to know if they have been separated, and where they are exactly, to better analyse the consequences of this anomaly,” he told VIPs.

The following hour saw the technicians finding their important children, and Arianespace speedily put out a statement saying that the satellites had been confirmed to have separated from their compartments within the rocket’s faring and were in an orbit, and – importantly – communicating to their ground station engineers.

Further investigation during the following 24 hours confirmed that SES-14, which as an ‘all electric’ craft which was always expected to take some four-to-six months to reach its target orbit, would now take about four weeks longer. SES’s statement added: “SES confirms that the spacecraft is in good health, all subsystems on board are nominal, and the satellite is expected to meet the designed life time.  SES-14 will be positioned at 47.5 degrees West to serve Latin America, the Caribbean, North America and the North Atlantic region with C- and Ku-band wide beam coverage and Ku-band high throughput spot beam coverage.”

YahSat admitted to some “challenges” in its launch that “differed from the flight plan” but that Al Yah 3 was healthy and operating nominally. “A revised flight plan will be executed in order to achieve the operational orbit and fulfil the original mission,” said their statement.

Arianespace says that it will mount an independent inquiry board, headed by the European Space Agency, to investigate the problems.







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