Elon Musk’s goal is to send SpaceX’s first cargo mission to Mars by 2022. A second mission, with both cargo and crew, is targeted for 2024. The objectives of the first mission would be to identify hazards, confirm water sources, and the like. The primary goal of the second mission would be to build a propellant depot and prepare for future crew flights. These two initial missions, as stated on SpaceX’s official website, would signify the beginning of our civilization’s Mars base.

The ambitious South African business magnate is slowly but surely moving his company and our civilization in this direction. However, at a recently held panel discussion, three key figures from the historic Apollo 17 mission — Harrison “Jack” Schmitt, Gerry Griffin, and Jim Head — suggested that we need to go back to the Moon before pursuing more distant space journeys.

Held in Texas to commemorate the 45th anniversary of Apollo 17 — our last mission to the Moon — the panel was live-streamed on Space.com. Harrison “Jack” Schmitt, lunar model pilot, flight director Gerry Griffin, and scientist Jim Head reminisced about the Apollo 17 mission and reflected on our plans to colonize Mars. What does the future hold?

In Schmitt’s opinion, “Mars ain’t gonna be easy.”

There are operational issues related to landing and working on Mars, so we should perhaps work them out closer to Earth. The Moon, he claims, is the perfect place for that. Apart from that, Schmitt thinks communication delay will be one of our biggest problems.

“Even when we’re working on Mars, I think that the science backroom is going to be even more important than it was for Apollo because of the planning activity that’s going to have to go on there due to the communication delays.”

Gerry Griffin agreed, adding that “we’ve got to get our mojo back.” Griffin added that if we want to send humans out into deep space, we need different kinds of spacecraft and life-support systems, as well as better ground support systems. Furthermore, they added, the long distance makes everything more difficult. Apollo 17 veterans illustrated this with an example: If we send a crowded spacecraft into deep space, but, for some reason, the mission has to be aborted mid-flight, how will we go back to Earth?

“You’d need to engineer your landing craft so that you can abort to land [on Mars] and work out the problems there,” Schmitt said. “To me, it’s just common sense that you would not do that. And that’s a challenge.”

Harrison Schmitt suggested we work out similar issues by doing lunar missions. This would help us “figure out what are we missing operationally that we didn’t think of with respect to preparing for Mars.”

In December 2017, President Donald Trump signed a new order, the Space Policy Directive 1. As the Verge noted at the time, the Moon could be a pit stop on our journey to Mars. Some, however, consider these missions to the Moon an “unnecessary detour.”

“Money spent on a Moon base is money you’re not spending on going to Mars,” Casey Dreier, the director of space policy at the Planetary Society told Slate in October last year.