While SpaceX founder Elon Musk has expressed a preference for focusing on missions to Mars over the Moon, NASA experts argue that lunar exploration is critical for the development of technologies necessary for human missions to the Red Planet.
Musk, in a January 2 post on X (formerly Twitter), made it clear that he believes the Moon is a distraction from the goal of reaching Mars. “No, we're going straight to Mars. The Moon is a distraction,” Musk wrote in response to a suggestion about producing liquid oxygen on the Moon for Starship missions to Mars. His comments did not completely rule out lunar exploration but indicated a preference for prioritizing Mars missions. SpaceX has received around $4 billion in NASA contracts to develop a lunar version of its Starship for the Artemis 3 and 4 missions, which are scheduled for later in the decade.
Despite Musk's ambitions, NASA engineers have stressed the importance of first proving key technologies on the Moon before attempting human missions to Mars. During a panel at the AIAA SciTech Forum on January 7, NASA experts voiced their concerns about the viability of Mars missions without prior testing on the Moon.
Michael Chappell, a member of NASA's Mars Architecture Team, emphasized the Moon's value as a testbed for Mars mission technology. “The moon is an outstanding testbed that we have for development of Mars,” Chappell stated. “To me, it's pretty critical to go back to the moon before we go on to Mars.”
One of the primary challenges for human missions to Mars is the impact of long-duration space travel on human health. “We have a substantial gap in knowledge about the health impacts of long-duration space travel, which is going to be necessary for a trip to Mars,” Chappell explained. Testing these factors on the Moon, he noted, would allow NASA to gain insights that would be invaluable for future Mars missions.
Dayna Ise of NASA's Mars Campaign Office echoed this sentiment, pointing out that while the International Space Station (ISS) has provided some data on life support systems for Mars missions, more testing will be necessary. “There is going to be no resupply for a Mars mission,” she noted, contrasting it with the regular resupply missions to the ISS. “On the moon, we will learn a lot about resupply and how we do logistics for lunar missions, but then all of that we have to leverage to figure out how to do a mission with no resupply.”
In addition to life support and logistics, lunar missions are expected to provide valuable data on power systems. Jeremiah McNatt, NASA's principal technologist for power systems in the Space Technology Mission Directorate, emphasized the potential for testing power technologies on the Moon. “There are so many power technologies you can demonstrate first, from the generation side to storage,” McNatt said. These tests will be crucial in supporting future Mars missions.
As part of its Moon to Mars Architecture, NASA selected fission reactors as the preferred power source for crewed Mars missions. McNatt noted that testing such systems on the Moon would reduce risks and costs for Mars expeditions. “Surface power technology demonstrations during the Artemis campaign would significantly reduce risk for initial crewed missions to Mars, serve as pathfinders for power system operations, and ultimately reduce the cost of implementing systems for Mars,” he stated.
Although the technologies for lunar and Martian missions will not be identical, the lessons learned from the Moon will be crucial in preparing for Mars. For example, the design of radiators for power systems on Mars will need to account for the planet's atmosphere and dust, which will be more challenging than the conditions on the Moon.
Dust also poses a significant challenge for life support systems. Ise noted that while lessons learned from lunar dust mitigation will be helpful, Mars dust presents unique problems. “What we are going to learn on the moon when it comes to dust is not going to be directly applicable to Mars dust,” she said. The differences in dust between the two celestial bodies will require different strategies for mitigation.
While SpaceX continues to push for rapid Mars exploration, NASA's experts argue that the Moon offers an essential proving ground for the technologies and systems needed for human missions to Mars.