The launch of the Vega launch vehicle, which took place yesterday, November 17, as part of the VV17 mission under the Arianspace program, was unsuccessful. At the final stage of placing the payload into orbit, the upper stage AVUM deviated from the specified trajectory, which subsequently led to the loss of control over it and the declaration of two satellites as lost.
According to the official message Arianspace, it was previously established that the incident was caused by an integration error during the installation of the AVUM overclocking unit.
According to Roland Lagier, CTO of Arianespace, quoted by the press service of Yuzhmash, it was found that the cables leading to the traction control actuators on the upper stage were turned over when the engine was mounted on the upper stage. A cabling issue caused the engine to move the injector in the wrong direction in response to commands from the missile guidance system. This led to the rocket losing control immediately after the launch of the fourth stage engine of the launch vehicle. Laguire described inverted cables as a “human error” rather than a design problem.
The RD-843 main engine block is manufactured at Yuzhmash under a contract with AVIO (Italy) and is supplied to the customer for subsequent installation on the fourth stage of the Vega LV (aka the AVUM upper stage).
“Thus, the cause of the incident is not structural defects of the RD-843 main engine block or defects in its manufacture at Yuzhmash. Moreover, attempts by some biased and unscrupulous media outlets to blame Yuzhmash for the accident are unfounded, ”the company said in a statement.
However, no final conclusions have been made yet. Arianspace said in a statement that “In line with their standard protocols, Arianespace and the European Space Agency (ESA) will establish an independent Experimental Commission chaired by Daniel Neuenschwander, Director of Space Transport at ESA, and Stefan Israel, Executive Director of Arianespace, on 18 November. The panel will provide detailed evidence to explain why action was not taken to detect and correct the integration error.
In connection with the incident, Yuzhmash expressed its support for Arianespace and its cooperation partners.
“The human factor and related failures is an integral part of our joint work. The main thing is to draw the right conclusions and make every effort to prevent similar cases in the future, "Yuzhmash summed up.