HOUSTON — An organization of current and former space travelers is offering its expertise to NASA as the agency works towards a “quite aggressive” goal of landing people on the moon in five years.

Leaders of the Association of Space Explorers (ASE), a professional group comprised of about 400 people who have made at least one orbit of the Earth, said at a press conference at the beginning of their week-long 32nd Planetary Congress here Oct. 14 that their experience in spaceflight could be critical to the success of the Artemis program.

“We’ve been, in the last few years, trying to become better known as a resource for human spaceflight,” said Michael Lopez-Alegria, a former NASA astronaut and president of ASE. “It’s hard to argue against the vast majority of people that have flown in space.”

Lopez-Alegria called 2024 deadline for returning humans to the moon, set earlier this year by Vice President Mike Pence, as a “quite aggressive” timetable, but one that also serves a purpose. “In any complex program like that, somebody needs to draw a line in the sand,” he said. “It may be aspirational, but without something like that it’s difficult to get people pulling in the same direction.”

Other ASE representatives endorsed the international aspects of Artemis, building upon the experience of the International Space Station. “I’m very happy that, as I call it, the blueprint of the ISS is also working in this respect,” said Reinhold Ewald, a former German astronaut who leads ASE’s European chapter. “This is exactly how we envisage cooperation.”

International cooperation, he said, can provide a degree of redundancy. “To stand on many columns is better than to rely on one national technical column.”

One criticism of the international cooperation argument has been the lack of opportunities for non-NASA partners, at least in the program’s initial phases. While Ewald cited the European Space Agency’s development of the Orion service module, most of the rest of the initial infrastructure for landing humans on the moon, including the Space Launch System, first elements of the lunar Gateway and lunar landers, will be provided by NASA or American companies it contracts with.

Soichi Noguchi, a Japanese astronaut who leads ASE’s Asian chapter, didn’t see that as a problem. He noted “phase one” of the ISS was the Shuttle-Mir program, by NASA and Russia alone. “Initially it will start small, as a domestic project,” he said of Artemis. “But pretty soon they will want to expand.”

Noguchi is one of a number of ASE members who are still active astronauts, and he is training for an upcoming mission to the ISS. Because of that, he said he wasn’t in a position to formally endorse the Artemis program. However, he said that he and fellow active astronauts “are very excited to know that NASA is moving towards the moon by 2024.” He added that he expected the Japanese government to make a “huge decision pretty soon” on its role in the program.