WASHINGTON — An Ariane 5 successfully launched a European spacecraft on an eight-year journey to Jupiter April 14 on the penultimate flight of the venerable rocket.

The Ariane 5 lifted off from the European spaceport at Kourou, French Guiana, at 8:14 a.m. Eastern after weather scrubbed a launch attempt the previous day. The Jupiter Icy Moons Explorer, or JUICE, spacecraft separated from the Ariane upper stage 26 minutes after liftoff.

Controllers made contract with JUICE about 40 minutes after liftoff and, a half-hour later, deployed its two large solar arrays with a total area of 85 square meters that will generate power for the six-ton spacecraft.

The acquisition of signals from JUICE took place a little later than expected, although still within the nominal window for doing so. Solar array deployment took place a little earlier than expected. Jean-Marc Nasr, head of space systems at Airbus Defence and Space, explained at a post-launch briefing that the array deployment took place earlier because the sun acquisition by spacecraft systems was precise. “It is a sign of a perfect mission,” he said.

The launch starts an eight-year journey for JUICE to reach Jupiter and three of its largest moons. The Airbus-built spacecraft will perform several gravity-assist flybys to reach Jupiter, starting with a joint flyby of the Earth and the moon in August 2024. Additional Earth flybys are scheduled for September 2026 and January 2029, along with a Venus flyby in August 2025.

JUICE will enter orbit around Jupiter in July 2031, performing 35 flybys of Europa, Ganymede and Callisto to characterize their surfaces and subterranean oceans, including determining if they are habitable. JUICE will go into orbit around Ganymede in December 2034 through the end of its mission, currently planned for September 2035.

“I think this is something that Europe can be extremely proud of,” Josef Aschbacher, director general of ESA, said at the post-launch briefing. “This is a mission that is answering questions of science that are burning to all of us.”

JUICE, with an estimated total cost of 1.5 billion euros ($1.65 billion), will attempt to answer those questions with a suite of 10 instruments, one of which was contributed by NASA. The Japanese space agency JAXA and Israel Space Agency are also partners on the mission, contributing parts of other instruments.

The launch was the sixth Ariane 5 flight to carry ESA missions, a total that includes the December 2021 launch of NASA’s James Webb Space Telescope that features significant ESA contributions. It was the 116th Ariane 5 launch overall, dating back to 1996.

Only one more Ariane 5 flight remains, a launch tentatively scheduled in late June of two European government communications satellites, France’s Syracuse 4B and Germany’s Heinrich Hertz.

“I think it’s a wonderful symbol to have made this one with ESA and the very last for Germany and France,” Stéphane Israël, chief executive of Arianespace, said at the post-launch briefing.

The Ariane 5 is being replaced by the Ariane 6, whose first flight has been delayed by several years. The most recent date announced by ESA for the inaugural Ariane 6 flight is late 2023, amid speculation it could slip again into 2024.

Aschbacher did not give a new estimate for the debut of the Ariane 6. “We are working very hard and doing everything to get it on the launch pad as quick as we can,” he said. “We have to go through some decisive milestones in the next couple of weeks, but certainly we are on a good track.”

“I feel a bit sad that this wonderful rocket is going out of service,” he said of the Ariane 5, but added that Ariane 6 “will be an equally good launcher.”

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...