Ariane 5 launches for the final time

One chapter in European access to space came to a close July 5 with the final launch of the Ariane 5, but the beginning of the next chapter faces additional delays. An Ariane 5 lifted off from the European spaceport at Kourou, French Guiana, at 6 p.m. Eastern. The launch had been scheduled for June 16 but was postponed a day in advance after Arianespace concluded that three pyrotechnical transmission lines used for the separation of the rocket’s solid rocket boosters needed to be replaced. The company rescheduled the launch for July 4, only to delay it an additional day because of strong upper-level winds. As with so many Ariane 5 missions, this launch, designated VA261, carried two communications satellites destined for geostationary transfer orbit. Nearly 30 minutes after liftoff, the rocket deployed Heinrich-Hertz-Satellit, a spacecraft built by OHB for the German Space Agency on behalf of other German government agencies. The 3,400-kilogram satellite will test advanced communications technologies. About three and a half minutes later, the rocket deployed the other payload, the Syracuse 4B satellite for the French military. The 3,570-kilogram satellite was developed by a consortium of Airbus Defence and Space and Thales Alenia Space, using an Airbus Eurostar 3000 bus.

An Ariane 5 lifts off for the final time July 5 carrying two European government communications satellites. Credit: ESA-CNES-Arianespace/Optique video du CSG/P. Piron

“It is a success for ‘Team Europe’ tonight with this last and final Ariane 5,” Stéphane Israël, chief executive of Arianespace, said on the company’s webcast of the launch after confirmation of successful payload deployment.

“Thanks for ArianeGroup, Arianespace and CNES. It was a wonderful launch, even if it is the last one,” said Gen. Michel Sayegh, director of space programs for the French armaments agency DGA during the launch webcast.

The launch was the 117th and final flight of the Ariane 5 over 27 years. The vehicle made its first, unsuccessful launch in June 1996, and suffered a partial failure on its second launch in October 1997 before an unqualified success on its third launch in October 1998. The rocket’s ability to carry two large geostationary communications satellites at once made it a key vehicle for many years in the commercial space industry during an era when geostationary communications satellites dominated the market.

The European Space Agency also regularly used the rocket for several science missions as well as the launch of five Automated Transfer Vehicle cargo spacecraft to the International Space Station between 2008 and 2014. In perhaps the rocket’s highest-profile launch, it successfully launched the James Webb Space Telescope for NASA on Christmas Day 2021, delivering it on a trajectory so accurate it had the effect of significantly increasing the spacecraft’s lifetime by reducing the amount of propellant needed for trajectory correction maneuvers.

“Ariane 5 is now over, and Ariane 5 has perfectly finished its work and really is now a legendary launcher,” Israël said. “But Ariane 6 is coming.”

Waiting on Ariane 6

In the lead up to the final Ariane 5 launch, Arianespace has advertised a “spaceflight continuum,” of past and future rockets, but that continuum is not necessarily continuous. The Ariane 5 overlapped with the end of the Ariane 4 rocket, which made its last launch in 2003. ESA had originally planned for a similar overlap between the end of the Ariane 5 and the introduction of its successor, the Ariane 6.

However, the development of Ariane 6 has been plagued by delays that have pushed out its first launch, once planned for 2020, by several years. In October 2022, ESA said it projected the first launch to take place in the fourth quarter of 2023, but it is increasingly likely the launch will slip into 2024.

Executives with OHB, a supplier on the Ariane 6 program, said in an earnings call in May that they expected the first Ariane 6 launch to take place in early 2024, and no later than May 2024. “I am getting more and more confident we will see the first launch of Ariane 6 early next year,” Marco Fuchs, chief executive of OHB, said during the call.

ESA and Arianespace have declined to provide an updated launch date for that inaugural mission. “Today it would be speculative to mention a launch date,” ESA Director General Josef Aschbacher said during a press briefing June 29 after an ESA Council meeting in Stockholm. “We have to go through a number of technical milestones over the summer period but I promise, after the summer in September, we will indicate a period which is the target period for the Ariane 6.”

Those milestones include a hot-fire test of the Ariane 6 upper stage scheduled for July at a test facility in Lampoldshausen, Germany, which will be followed by a second test in the fall to test its performance in what ESA calls “degraded cases.” Assembly of the first flight model of the Ariane 6 is planned to begin in November in French Guiana, according to an ESA update published June 8.