Humans could stay on the Moon for lengthy periods during this decade, a Nasa official has told the BBC.
Howard Hu, who leads the Orion lunar spacecraft programme for the agency, said habitats would be needed to support scientific missions.
He told Sunday with Laura Kuenssberg that Wednesday’s launch of the Artemis rocket, which carries Orion, was a “historic day for human space flight”.
Orion is currently about 134,000km (83,300 miles) from the Moon.
The 100m-tall Artemis rocket blasted off from the Kennedy Space Center as part of Nasa’s mission to take astronauts back to Earth’s satellite.
Sitting atop the rocket is the Orion spacecraft which, for this first mission, is uncrewed but is equipped with a ‘manikin’ which will register the impacts of the flight on the human body.
Wednesday’s flight followed two previous launch attempts in August and September that were aborted during the countdown because of technical woes.
Mr Hu told Laura Kuenssberg that watching Artemis lift off was “an unbelievable feeling” and “a dream”.
“It’s the first step we’re taking to long-term deep space exploration, for not just the United States but for the world,” he said.
“And I think this is an historic day for Nasa, but it’s also an historic day for all the people who love human space flight and deep space exploration.