FARNBOROUGH, England — The European Space Agency is optimistic that its “launcher crisis” is behind it after the mostly successful inaugural launch of the Ariane 6 earlier this month.

Speaking at a briefing at the Farnborough International Airshow July 22, Josef Aschbacher, ESA director general, hailed the July 9 launch of the rocket on a test flight that successfully deployed several smallsats in orbit, but suffered a malfunction in the auxiliary power unit (APU) in the rocket’s upper stage that prevented it from performing a final deorbit burn.

“The launch was 100% successful,” he said, noting that the launch phase of the mission was designed as its first hour and six minutes after liftoff, when the upper stage reached orbit and deployed its smallsat payloads.

The second phase, or “technical experiment,” involved testing the upper stage while in orbit. It was during this phase that the stage’s APU malfunctioned, preventing the Vinci engine from performing a final deorbit burn. That stage remains in low Earth orbit, with two reentry vehicles, intended to deploy after the burn, still attached.

Neither ESA nor the other organizations involved in the flight have disclosed details about what caused the APU problem. Aschbacher said the Ariane 6 task force plans to meet Friday, July 26, and will release its findings to date either that day or the following Monday. “We’re focused on keeping our promise on being transparent so you know exactly what’s going on,” he said.

In an interview after the briefing, he said he wanted to wait until after the task force meeting at the end of the week to discuss the APU malfunction in more detail, but stressed that it would not affect plans for the first operational Ariane 6 mission, expected to carry a French reconnaissance satellite known as CSO 3, set for late this year.

“The CSO flight does not need the APU, so from that point of view it’s not critical,” he said, suggesting the APU may not be included on that launch.

The next flight after CSO was to carry a geostationary weather satellite called MTG-S1 for Eumetsat, but that agency announced last month it would launch the satellite instead on a Falcon 9, a move that surprised and disappointed European space officials like Aschbacher. He said he talked with Eumetsat officials at the Ariane 6 launch but got no indication that the agency would backtrack after the success of the inaugural flight. He noted Eumetsat’s decision, coming a couple weeks before the launch, was tied to the agency’s schedule of twice-yearly council meetings.

“We’re looking at different options” for a replacement payload for the launch that was to fly MTG-S1. “We have one option in particular in mind,” he added, but did not disclose it.

ESA is also preparing for the return to flight of the Vega C, grounded since a launch failure in December 2022. A separate task force is working on that effort, Aschbacher said. “Since the beginning of the task force, which was the end of last year, we have not lost a single day along the schedule,” he said.

That return-to-flight mission, carrying the Senintel-1C radar imaging Earth science satellite, is scheduled to fly between mid-November and mid-December, with a more specific date to come after a second test firing of the redesigned second-stage motor at the end of September or early October.

Aschbacher said in the interview that another factor in the launch date for Vega C will be the upcoming final launch of the original version of the Vega rocket, currently set for September carrying Sentinel-2C. “There’s a certain number of weeks necessary for the ground operations and the preparations in Kourou,” the spaceport that hosts Vega and Ariane launches, he said. Any slip in that Vega launch could push back the Vega C launch, he said, even if the Vega C is itself ready to launch.

He said the launch of Ariane 6 was a sign that the “launcher crisis” in Europe had come to an end. “I see so many reports about launchers and the launcher crisis,” he said at the briefing, while acknowledging that he had emphasized that crisis, which left Europe without independent access to space, many times to “sharpen the focus” for Europeans on ways to resolve it.

“You can imagine,” he said of the launch, “how important this success was for all of us. For ESA, for space in Europe, it was really huge.”

He offered a similar message in an earlier speech at the “Space Zone” part of the air show. “This launch was so important for the autonomy of Europe and the strategic importance of space,” he said. “It was an absolute success that Europe needed because it brings us back into space with our own rocket.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...