"Now, NASA is working to build a sustainable, open architecture that returns humanity to our nearest neighbor," Jim Bridenstine, the administrator of the U.S. space agency, said in a statement to a Senate committee on Wednesday.

"We are building for the long term, going to the Moon to stay, and moving beyond to Mars."

The next manned mission to the moon will require leaps in robotic technologies and a plan for NASA to work with private companies such as Elon Musk’s SpaceX or Jeff Bezos’ Blue Origin to help cut the cost of space travel.

Using NASA’s Space Launch System, a heavy-lift rocket being built for a debut flight in late 2020, the agency is aiming to return humans to the moon by 2024 in an accelerated timeline set in March by the Trump administration.

No humans have launched from U.S. soil since the space shuttle program ended in 2011.

NASA officials say exploration of the moon and Mars is intertwined, with the moon becoming a testbed for Mars and providing an opportunity to demonstrate new technologies that could help build self-sustaining extraterrestrial outposts.

“We are working right now, in fact, to put together a comprehensive plan on how we would conduct a Mars mission using the technologies that we will be proving at the moon,” Bridenstine told reporters on Monday, adding that a mission to the Red Planet could come as soon as 2033.

Technologies that can mine the moon’s subsurface water ice to sustain astronaut crews, but also to be broken down into hydrogen and oxygen for use as a rocket propellant, could be crucial for missions to Mars. The planet is reachable in months-long missions when at its closest orbital approach of 35.8 million miles from Earth.

“It’s utilization versus curiosity,” said roboticist and research professor at Carnegie Mellon University William Whittaker, comparing the Artemis program, as the new lunar mission has been dubbed, with Apollo. Artemis is the twin sister of Apollo and goddess of the moon in Greek mythology.

REUTERS