NASA has launched the countdown for humanity’s first crewed mission to the Moon in more than five decades, with liftoff targeted for Wednesday evening.

The 32-storey Space Launch System rocket is set to carry four astronauts into space. After spending about a day orbiting Earth, their Orion spacecraft will head toward the Moon, perform a flyby and return directly without landing. The mission is expected to last nearly 10 days, ending with a splashdown in the Pacific Ocean.

“Our team has worked extremely hard to get us to this moment,” said launch director Charlie Blackwell-Thompson, adding that all systems are currently in excellent condition.

Officials said the rocket is performing well after recent repairs, while weather forecasts indicate favourable launch conditions.

The Artemis II mission was initially scheduled for February but was delayed due to hydrogen fuel leaks. Although those issues were resolved, a clogged helium pressurisation line forced the rocket back to the hangar last month. It returned to the launch pad about a week and a half ago, and the joint US-Canadian crew arrived at the site on Friday.

Unlike the Apollo program missions between 1968 and 1972, which included only male astronauts, Artemis II features a more diverse crew, including a woman, a person of colour and a non-US citizen.

Mission pilot Victor Glover said he hopes the mission will inspire young people, especially those from underrepresented communities, to see themselves reflected in space exploration. At the same time, he expressed hope that such “firsts” will eventually no longer be notable as space travel becomes a shared human endeavour.

NASA has a launch window through the first six days of April, after which it will pause attempts until later in the month.