Last month, a full-scale test model of Europe's Ariane 6 was put to the test on its launch pad in the jungles of French Guiana. For the first time, the launch team at the tropical spaceport loaded cryogenic liquid hydrogen and liquid oxygen into the Ariane 6 over the course of a marathon 26-hour test campaign.
But it took a week for the European Space Agency, which is funding the 3.8 billion euro ($4.1 billion) development of Ariane 6, to release an update on the test. It turned out the launch team could not accomplish one of the main goals of the countdown rehearsal: A brief four-second ignition of the Ariane 6's main engine.
An ESA spokesperson described the test on July 18 as "very satisfactory" even though the engine didn't light. It's true that the simulated countdown checked off some key objectives. The launch team in French Guiana—consisting of membership from ESA, prime contractor ArianeGroup, and the French space agency CNES—supervised the loading of more than a half-million liters of liquid hydrogen and liquid oxygen into the 207-foot-tall (63-meter) Ariane 6.
"During the 26-hour exercise, the teams successfully tested many degraded and contingency modes, demonstrating that the launcher and the launch base fit correctly," ESA said. "Operational procedures, lower and upper stages, avionics, software, launch base, and control bench worked correctly together, and the performance of the full launch system was measured with excellent results."
The countdown test on July 18 proceeded up to the time that the Ariane 6's Vulcain 2.1 main engine would have ignited during a real launch attempt. Going into the test, officials planned to fire the engine for approximately four seconds while the Ariane 6 remained on the pad. Managers called off that objective because time ran out, ESA said, without offering additional detail.
The Ariane 6 countdown test originally started July 13, but the countdown that day was cut short before the test continued five days later. ESA didn't mention that in its press release discussing the outcome of the countdown rehearsal.
You won’t get to watch the Ariane 6 hot-fire test
An ESA spokesperson told Ars that engineers are considering whether to mount another countdown rehearsal to complete the four-second engine-firing milestone or to go directly to a follow-up simulated countdown that was already planned for September. That one will culminate in a longer Vulcain 2.1 engine firing that could last up to 500 seconds, approximating the duration of a main engine burn during launch.
The space agency's spokesperson said ESA is not planning to provide live video of the long-duration Ariane 6 test-firing in French Guiana. That's disappointing and would be a missed opportunity for ESA to engage with the taxpayers footing the bill for this new rocket.
Other entities like ArianeGroup and the French space agency occupy the launch control center consoles for the Ariane 6 testing. ESA not only controls the purse strings but also has the final say in releasing updates on the Ariane 6 program.
ESA's decision not to broadcast live video of the Ariane 6 hold-down test-firing easily contrasts with NASA, which provided live coverage of two hot-fire tests for its Space Launch System rocket in 2021. Like the Ariane 6, NASA's SLS Moon rocket is a publicly funded venture.
Other companies also have livestreamed test firings of their high-profile rockets. SpaceX provided live video of a multi-engine test-firing of its Super Heavy booster earlier this year before it launched on SpaceX's first full-size Starship test flight. In June, United Launch Alliance produced a live webcast for a six-second engine firing of its new Vulcan rocket.
Josef Aschbacher, ESA's director general, has promised more "openness and transparency" from the space agency. After several reporters recently voiced concerns about ESA's opacity, Aschbacher outlined several steps in this area, including more access to ESA officials for journalists and the public release of more ESA documents. Another way ESA could fulfill Aschbacher's pledge is to be more forthcoming with detailed and timely updates on Ariane 6, the agency's most expensive program.
Aschbacher has prioritized modernizing ESA, which draws upon funding from 22 European members. Some of his proposals include a more commercially focused procurement framework, allowing Europe's private sector to move faster than ESA's sluggish bureaucracy. France, Germany, and to a lesser extent, Italy drive Europe's government-funded launch vehicle programs.
But getting all of ESA's member states to buy in to high-level reforms is not easy. Parochial politics are at play, with each nation desiring "geographic return"—i.e., jobs—commensurate with their investment. By definition, that approach limits flexibility and agility in developing a new rocket.
Approving a livestream of the Ariane 6's upcoming engine hot-fire test should be an easier lift. After all, ESA already regularly hosts live launch broadcasts from French Guiana.
These are important times for the Ariane 6 program, which initially targeted an inaugural test launch in 2020. The debut of Ariane 6 is now expected sometime next year—four years late—but ESA has declined to offer a more specific timetable until more test results give the agency some confidence in the schedule.
Aside from the launch pad tests in French Guiana, engineers in Germany plan a pair of firing tests of the Ariane 6's restartable upper-stage engine later this year. By the end of 2023, ESA hopes to disassemble the Ariane 6 test vehicle currently undergoing testing in French Guiana, then install the Ariane 6 assigned for the first flight.
The Ariane 6 delays have left Europe largely without independent access to space, causing ESA to move some of its payloads to launch with SpaceX, a rival to the Ariane rocket on the global marketplace.
The final European Ariane 5 rocket launched on July 5. ESA originally wanted at least a couple of years with both Ariane 5 and Ariane 6 flying. With Ariane 5 now retired, there's even more pressure for ESA and ArianeGroup (the parent company of French launch services company Arianespace) to get Ariane 6 flying as soon as possible.
They need to get it right. A launch failure early in the Ariane 6 program would set back Europe's launch efforts even more. Once operational, ESA will hand over the Ariane 6 to Arianespace for commercial exploitation.
That's not to mention burning questions about the competitiveness of Ariane 6 on the international commercial launch market dominated by SpaceX's partially reusable Falcon 9 rocket. A number of other reusable launchers are on the horizon, but Ariane 6 is based on a single-use expendable design. That puts Ariane 6 at a disadvantage against international competitors and has led Aschbacher to write that Europe is in an "acute launcher crisis."
Speaking in June at the Paris Air Show, ESA's Toni-Tolker Nielsen said the Ariane 6 is projected to come in at higher costs per launch than first predicted. The Ariane 6's cost per flight will be about 40 percent lower than that of the now-retired Ariane 5, short of the goal of a 50 percent cost reduction, Nielsen said.
