WASHINGTON — Arianespace executives said Nov. 17 that the failure of a Vega launch the previous day was caused when the rocket’s upper stage tumbled out of control due to incorrectly installed cables in a control system.
In a call with reporters, Roland Lagier, chief technical officer of Arianespace, said the first three stages of the Vega rocket performed normally after liftoff from Kourou, French Guiana, at 8:52 p.m. Eastern Nov. 16. The Avum upper stage then separated and ignited its engine.
However, “straightaway after ignition” of the upper stage, he said, the vehicle started to tumble out of control. “This loss of control was permanent, inducing significant tumbling behavior, and then the trajectory started to deviate rapidly from the nominal one, leading to the loss of the mission.”
Analysis of the telemetry from the mission, along with data from the production of the vehicle, led them to conclude that cables to two thrust vector control actuators were inverted. Commands intended to go to one actuator went instead to the other, triggering the loss of control.
“This was clearly a production and quality issue, a series of human errors, and not a design one,” Lagier said.
Arianespace will convene an investigation commission, chaired by the European Space Agency’s inspector general, to confirm the cause of the failure and recommend corrective actions. That commission will start work as soon as Nov. 18, said Stéphane Israël, chief executive of Arianespace, on the call.
He emphasized that this failure was not linked to the previous Vega failure in July 2019. That launch, carrying an imaging satellite for the United Arab Emirates, failed because a structural problem with the rocket’s second stage that has since been corrected.
Israël added that the failure won’t affect launches of other Arianespace missions. The company has three Soyuz launches, two from Kourou and one from the Vostochny Cosmodrome in Russia, scheduled through the end of the year, and those launches will proceed while the Vega investigation continues. He added that the company will be “100% transparent” about the investigation and outcome.
The failure caused the loss of two spacecraft, the SEOSAT-Ingenio Earth observation satellite for Spain and the TARANIS satellite for France to study electromagnetic phenomena in the upper atmosphere.
“I want to present my deepest apologies to our customers,” Israël said. “This is part, unfortunately, of the launcher life.”
