Ariane 6 test
An Ariane 6 upper stage fires its Vinci engine during an Oct. 5 test at a DLR facility in Lampoldshausen, Germany. Credit: ESA

WASHINGTON — ArianeGroup has started static-fire tests of the upper stage of the Ariane 6 rocket, a key step in the development of the vehicle whose first launch remains uncertain.

ArianeGroup and the European Space Agency announced Oct. 6 that they started a campaign of hot-fire tests of the Ariane 6 upper stage and its Vinci engine at a test site in Lampoldshausen, Germany, operated by the German Aerospace Center (DLR). The test firing on Oct. 5 was the first of up to four planned to qualify the stage for flight.

“The completion of this hot-firing test is an important step on the way to the qualification of Ariane 6 and its successful inaugural flight,” André-Hubert Roussel, chief executive of ArianeGroup, said in a company statement.

The Vinci engine uses liquid hydrogen and liquid oxygen propellants and is designed to be re-ignited up to four times to enable complex payload deployments. The stage includes an auxiliary power unit to pressurize the propellant tanks in place of helium.

The test facility at Lampoldshausen is designed to simulate the conditions that the upper stage will experience during a launch, other than microgravity and vacuum. Once the hot-fire tests are complete, the stage will go to an ESA center in the Netherlands for acoustic and stage separation tests.

At the same time, other Ariane 6 hardware is being tested at the launch site in French Guiana, so called “combined tests” to study interfaces between the launch vehicle and ground infrastructure. The stages for the first flight model of the Ariane 6 are being assembled at ArianeGroup factories in Bremen, Germany, and Les Mureaux, France.

“We are working tirelessly to ensure the successful first flight and series production of Ariane 6, meeting the expectations of Arianespace’s prestigious European institutional customers as well as its commercial customers around the world,” Roussel said in the statement.

However, neither ArianeGroup nor ESA disclosed a date for that inaugural launch. Development of Ariane 6 has suffered significant delays and that first launch, once planned for 2020, has now slipped to 2023.

During a panel session at World Satellite Business Week in Paris Sept. 12, Stéphane Israël, chief executive of Arianespace, declined to give an updated estimate of when that first launch would take place, saying that ESA and Ariane 6 development partners would meet later in the month to update its status. They have since not reported any updates on when the vehicle might be ready for launch.

“Ariane 6 development is not a walk in the park,” Roussel said in comments at the opening ceremony of the International Astronautical Congress in Paris Sept. 18. “We’re all working like hell to put the rocket on the pad for the first launch.”

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...