Inverted cables sent Vega's upper stage tumbling — two satellites and €200M lost

On a November 2020 night from Kourou, French Guiana, the Vega rocket carrying Spain's first Earth-observation satellite SeoSat-Ingenio and France's Taranis research satellite malfunctioned eight minutes after liftoff, right after the first ignition of the Avum upper stage meant to deliver them to orbit. Engineers watched it deviate from its trajectory, shake and lose control; both satellites were lost.

Analysis of telemetry and manufacturing specifications concluded the cabling on the thrust vector control system must have been inverted when the upper-stage engine was assembled. Arianespace chief technical officer Roland Lagier attributed the failure to 'human error' during assembly, not the rocket's design. Arianespace and the European Space Agency formed an investigative commission to detail the causes and recommend changes, and chief executive Stéphane Israël apologised to clients.

The loss was brutal in the specifics: SeoSat-Ingenio represented ten years of work and €200 million invested by Spain, led by Airbus, and was not insured. It was also the second Vega failure of 2020 — a July mission had already destroyed a United Arab Emirates satellite insured for €415 million, then the biggest loss of its kind in the sector, though Lagier said the November failure 'had nothing to do' with the July one.

The root cause was assembly, not engineering: cables on the thrust vector control system were installed inverted, a two-wire mistake with mission-ending consequences.

Quality control failed to catch a physically simple error on the most stage-critical subsystem of the rocket.

It was Vega's second failure in four months, compounding the damage to the launcher's reliability record.

The flagship payload was uninsured, so the full €200 million cost of a decade's work fell on the public programme.

In launch vehicles the cheapest component is process: one cable reversed in assembly defeated a decade of engineering and every design margin.

The investigative commission was tasked with recommending changes to assembly and verification. Spain said the project still proved its industry could build complete space systems, and pointed to the €380 million LSTM contract it would lead. Spain remained dependent on other countries' satellites for Earth observation.