Investigation into upper stage failure during Ariane-6’s first launch completed
The Ariane-6 rocket investigation team, including people from the European Space Agency (ESA), CNES (France’s space agency), ArianeGroup (which built and owns the rocket), and Arianespace (which presently manages the rocket), has identified the issue that caused the rocket’s upper stage failure during the rocket’s first launch in July.
In a 16 September update, the Task Force announced that the investigation had identified a single temperature measurement that “exceeded a predefined limit” as the root cause of the anomaly. The tripped limit caused the software to trigger a shutdown of the APU which ensured the rocket’s Vinci upper stage engine could not be restarted for the final burn.
In order to remedy this issue and ensure a similar shutdown does not occur in the future, the ignition preparation sequence, specifically the APU chill-down sequence, has been changed. The updated flight software is already being tested as teams prepare for the rocket’s first commercial flight which is set to take place before the end of the year.
Because of that incorrect temperature, the upper stage did not do its final burn, thereby stranding the stage and two demonstration return capsules in the wrong orbit. This prevented the test return of both capsules, as well as the test planned de-orbit of the stage over the ocean.
The Ariane-6 rocket investigation team, including people from the European Space Agency (ESA), CNES (France’s space agency), ArianeGroup (which built and owns the rocket), and Arianespace (which presently manages the rocket), has identified the issue that caused the rocket’s upper stage failure during the rocket’s first launch in July.
In a 16 September update, the Task Force announced that the investigation had identified a single temperature measurement that “exceeded a predefined limit” as the root cause of the anomaly. The tripped limit caused the software to trigger a shutdown of the APU which ensured the rocket’s Vinci upper stage engine could not be restarted for the final burn.
In order to remedy this issue and ensure a similar shutdown does not occur in the future, the ignition preparation sequence, specifically the APU chill-down sequence, has been changed. The updated flight software is already being tested as teams prepare for the rocket’s first commercial flight which is set to take place before the end of the year.
Because of that incorrect temperature, the upper stage did not do its final burn, thereby stranding the stage and two demonstration return capsules in the wrong orbit. This prevented the test return of both capsules, as well as the test planned de-orbit of the stage over the ocean.