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Reversed cables on the Vega rocket’s upper stage control system apparently caused the launcher to fall just minutes after takeoff Monday night, a failure that led to the loss of a Spanish Earth observation satellite and a French research probe. Arianespace officials said Tuesday.
Officials from Arianespace – the French company that manages the Vega rocket launches – said on Tuesday that engineers examined telemetry data and documentation overnight and found that the most likely cause of the launch failure was a case of error. human.
The engineers concluded that the cables leading to the thrust vector control actuators on the upper stage were reversed, apparently an error due to the assembly of the upper stage motor, according to Roland Lagier, technical director of Arianespace. The thrust vector control system rotates the upper stage motor nozzle to direct thrust, allowing the rocket to control its orientation and steering.
The wiring problem caused the engine to move its nozzle in the wrong direction in response to commands from the rocket guidance system. This resulted in the rocket losing control and dropping immediately after starting the upper stage engine about eight minutes after launch.
Lagier called inverted cables a “human error” and not a design problem.
The 98-foot (30-meter) high Vega rocket took off from the Guiana European Space Center in South America at 20:52 EST on Monday (0152 GMT on Tuesday) with the Spanish Earth observation satellite SEOSAT-Ingenio and the French Satellite of Taranis research designed to study the mysterious electrical discharges of thunderstorms.
The solid-fueled lower three stages of the Vega rocket performed normally, accelerating the launcher to a speed of nearly 17,000 mph, or 7.6 kilometers per second, just short of the speed required to enter Earth’s orbit.
The Attitude and Vernier Upper Module, or AVUM, stage of the Vega rocket would have had to fire its main engine four times to deploy the SEOSAT-Ingenio and Taranis satellites in two slightly different orbits about 420 miles (676 kilometers) above Earth.
The first power up of AVUM was programmed to place the satellites in a preliminary parking orbit. Without the burn, the rocket and its two satellite payloads fell back to Earth and burned during atmospheric reentry. Any debris from the vehicle fell into an uninhabited area in the Arctic.
Arianespace and the European Space Agency will set up an independent commission to investigate the launch failure. ESA’s inspector general will lead the investigation, according to Stéphane Israël, CEO of Arianespace.
The launch incident on Monday evening was the second launch failure in the last three flights of the European Vega rocket program. Vega launchers have completed 14 consecutive missions successfully since the rocket’s debut in 2012, before a Vega flight failed in July 2019 with the Falcon Eye 1 military spy satellite for the UAE.
Investigators traced the cause of the Falcon Eye 1 crash to a “thermo-structural failure” on the front dome of the solid fuel second stage of the Vega rocket, which led to the launch vehicle crashing in flight.
The Vega rocket returned to service with a successful launch on September 2 that delivered 53 small satellites into orbit for numerous international customers. In addition to signaling the return to operation of the Vega rocket, the rideshare launch on September 2 demonstrated a new multi-satellite distributor aimed at helping Arianespace attract smaller satellite launch businesses.
The Vega rocket is capable of placing up to 3,300 pounds – 1.5 metric tons – of payload in a 435-mile (700-kilometer) high polar orbit.
An upgraded rocket called Vega C with more powerful first and second stage engines is scheduled for first launch in mid-2021. orbit with respect to the basic version of the Vega rocket.
Israel said Monday night’s mission failure had “nothing to do” with Vega’s failure last year.
The previous failure was linked to a weakness in the design, “Israël told reporters on Tuesday. He added that the design problem blamed for the 2019 failure has been corrected, resulting in the Vega rocket returning to the flight mission in September.
Israel said misplaced cables identified as the most likely cause of Monday night’s failure were a “quality and production problem.”
“We are looking at all the processes to better understand why this integration error has not been corrected,” said Israël.
Arianespace and ESA officials said they will hold a press conference once the investigation is over.
“We will be 100% transparent,” said Israël.
The AVUM upper stage structure is manufactured by Airbus and Ukrainian missile contractors Yuzhnoye and Yuzhmash supply the main engine of the AVUM stage, which consumes hydrazine and nitrogen tetroxide propellants.
Avio, the main Italian contractor for the Vega rocket, oversees the final integration of the upper stage of the AVUM.
The Spanish SEOSAT-Ingenio satellite traveled in the upper position of the Vespa dual payload dispenser of the Vega rocket, while the French research payload Taranis was launched into the lower berth of the Vega payload cover
The 1,650-pound (750-kilogram) SEOSAT-Ingenio satellite carried two optical cameras to capture high-resolution images for use in environmental monitoring, agricultural and forest management, mapping, urban planning, disaster response and border security .
Designed primarily for civilian use, SEOSAT-Ingenio was supposed to collect images for the European Commission’s Copernicus program, which includes a fleet of dedicated Sentinel environmental monitoring satellites. As a contributing mission in the Copernicus fleet, SEOSAT-Ingenio was to integrate data collected by Sentinel satellites distributed worldwide and free of charge.
SEOSAT-Ingenio was owned by the Spanish government, but the European Space Agency provided assistance to the project in technical and contractual matters. ESA was also tasked with organizing the satellite launch with Arianespace.
One of the main objectives of the SEOSAT-Ingenio project, initiated by the Spanish government in 2007, was to promote a growing Spanish space industry. About 80% of the spacecraft was manufactured in Spain.
“The SEOSAT-Ingenio program had two goals,” said Josef Aschbacher, director of Earth observation programs at ESA. “The first objective was to build an industrial capacity in Spain to implement a complete space system – a satellite, a ground system and a data analysis – and the second objective was to establish a strategic national Earth observation system, which was the SEOSAT system.
“The first goal has been fully achieved,” Aschbacher said on Tuesday. “The Spanish industry now has the full capacity to implement a complete space system … The second goal was not achieved due to the loss of SEOSAT-Ingenio in this unfortunate launch failure.”
Aschbacher said the SEOSAT-Ingenio satellite was not insured against launch or failure. It is normal practice for government missions not to acquire launch insurance, he said.
Juan Carlos Cortés, director of space and dual programs at the Spanish Center for the Development of Industrial Technology, helped the SEOSAT-Ingenio project cost around 200 million euros, or $ 236 million.
Aschbacher said ESA “is ready to support” the Spanish government to “explore possible options for establishing a national optical Earth observation system to replace the one that failed in this launch.”
The 175-pound (175-kilogram) French research satellite Taranis was designed to trace the origins of mysterious light phenomena above thunderstorms. Taranis, led by the French space agency CNES, allegedly attempted to untangle what triggers these brief flashes over thunderstorms and how transient events could affect conditions within the atmosphere or in space.
“We have lost the beauty of technology, the fruit of over 15 years of hard work in French industry and the CNES,” said Lionel Suchet, CNES chief operating officer. “But this kind of event is part of our difficult job and we have to face it together”.
Suchet said CNES will explore new possibilities for pursuing the research objectives of the Taranis mission.
“We have lost a satellite, but all is not lost,” Suchet said.
While the short-term schedule of Vega launches is clouded by the failure on Monday night, Arianespace will continue with preparations for three missions before the end of the year using Russian Soyuz rockets.
A Soyuz rocket launch is scheduled for November 28 from French Guiana with the UAE’s Falcon Eye 2 military spy satellite, followed by a Soyuz launch from the Vostochny Cosmodrome in Kazakhstan in mid-December with 36 OneWeb broadband satellites.
Another Soyuz mission is scheduled for launch in late December from French Guiana with the French Army’s CSO 2 optical reconnaissance satellite.
All three Soyuz missions are operated by Arianespace, which markets the launch services of Ariane 5, Soyuz and Vega.
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