Just a few days after a NASA official apparently confirmed the deadline of landing people on the Moon by the “second half of 2024”, another NASA spokesperson has suggested the “aggressive goal” of the current administration is highly unlikely to be met.

In fact, according to AP News, the top NASA official's words were: “I wouldn’t bet my oldest child’s upcoming birthday present or anything like that.”

The White House-imposed 2024 deadline came back in March, issued by Vice President Mike Pence at the fifth meeting of the National Space Council. Before that, NASA had a working deadline of 2028, but "that's just not good enough," Pence had said. “We’re better than that.”

Nobody has set foot on the Moon since the final Apollo mission, Apollo 17, in 1972.

"The United States must remain first in space in this century as in the last, not just to propel our economy and secure our nation but, above all, because the rules and values of space, like every great frontier, will be written by those who have the courage to get there first and the commitment to stay," said Pence.

Though an admirable goal, Kenneth Bowersox, acting associate administrator for human exploration and operations at NASA, told a Congressional subcommittee this week that other factors, like safety, funding, and overcoming the technical challenges that have so far prevented NASA from revisiting the Moon need to be considered.

Bowersox – former astronaut, commander of both the space shuttle and the International Space Station, and former vice president of astronaut safety at SpaceX – told the committee that while it was good for NASA to have “that aggressive goal” as a deadline to urge the agency on, they still needed to be realistic.

“What’s important is that we launch when we’re ready, that we have a successful mission when it launches, and I’m not going to sit here and tell you that just arbitrarily we’re going to make it,” he said. Though, he did add: “There’s a lot of risk in making the date, but we want to try to do it.”

It’s no secret that the current president is more interested in a mission to Mars than the Moon, but a Moon landing is integral to NASA’s eventual plan to get there. Named Artemis, after Apollo’s sister, NASA’s Moon exploration mission has a two-phase plan: Land astronauts on the Moon in 2024, and establish a permanent lunar base by 2028.

NASA and other space agencies are working on a new space station, called the Lunar Gateway, which will orbit the Moon. As well as a science lab and holding area for equipment like rovers, this will also provide a refueling station for spacecraft, and a break for astronauts, the journey to Mars being an estimated eight months. The Gateway is scheduled for assembly in 2022, with crewed missions taking place in 2024. However current plans suggest it won’t be complete until 2026.

Other aspects that may hinder the tight 2024 deadline include a lack of rovers, landers, new spacesuits, and, vitally, NASA's much-delayed Space Launch System (SLS) – which will be the first to launch from US soil since 2011 – and is currently set to miss its launch date of 2020. Asked if private companies like SpaceX may actually beat NASA to the Moon, Bowersox still has faith in the agency, though.

“I’d still bet on us – but they might be part of our program.”