A test of an Ariane 6 upper stage that took place on 7 December was aborted after just two minutes. The cause of the early abort is currently under investigation.
The Ariane 6 upper stage test took place at the DLR facility in Lampoldshausen, Germany. An initial full-duration test firing of the rocket’s upper stage was completed at the facility on 1 September. The stage was fired for a total of 680 seconds. The purpose of this second test was to demonstrate the performance of the stage in degraded conditions.
Neither the European Space Agency nor prime contractor ArianeGroup announced the results of the test following the early abort. It wasn’t until a question was asked during a 14 December press briefing following an ESA council meeting that the outcome was revealed by the agency’s director of space transportation, Toni Tolker-Nielsen. According to Tolker-Nielsen, the issue is currently under investigation by ArianeGroup.
Following a successful full-duration core stage test that took place on 23 November, ESA announced that the maiden Ariane 6 flight would take place between 15 June and 31 July 2024. The agency’s director general, Josef Aschbacher, explained that a 15 June launch date would require a flawless run-up to the flight. With the aborted upper stage test, that goal appears to already be unachievable. However, during the 14 December briefing, Tolker-Nielsen did state that the early abort would not affect its ability to launch within the stated timeframe.
Regardless of whether or not the early abort will impact the current timeline leading up to the maiden flight of Ariane 6, ESA’s failure to disclose the result of the test in the week leading up to the 14 December briefing does fly in the face of Aschbacher commitment for increased transparency.
Update: 19 December statement from ESA
“Two minutes after the Vinci engine and APU were fired up, the test was automatically aborted when sensors detected that some parameters had gone beyond predetermined thresholds. The engines were shut down with the nominal sequence, the upper stage test model and test bench entered a safe condition, and the tanks were emptied.”
“This HFT-4 test went beyond the normal flight profile for Ariane 6. The stage will not operate in such a test configuration on the inaugural flight. Teams are analysing test hardware and investigating possible root causes of the abort, with results expected mid-January 2024.”
