SpaceX chief says Moon lander needs 6 to 8 fuel flights, not 22

The number of rocket launches required to fuel a crewed lunar lander dropped from 22 to a range of 6 to 8 in a public dispute between SpaceX and a NASA advisory group. This difference directly impacts the timeline for Artemis IV, the mission scheduled to send astronauts to the Moon in 2028. Fewer launches mean less time spent in orbit and reduced logistical complexity for the crewed flight.

The conflict began at the Aerospace Safety Advisory Panel's quarterly meeting on Thursday. Charlie Precourt, a panel member and former NASA astronaut, identified lander fueling as a primary risk. As reported by Ars Technica, Precourt stated, "We need to keep our eyes on numerous required fuelings for the lander," adding that the latest estimate stood at around 22 flights. Eric Berger of Ars Technica shared the remark on social media, which led to a direct response from Elon Musk.

"That's way too high," Musk wrote in reply. "Actual number will be more like 6 to 8." The disagreement stems from the physical limitations of Starship. The vehicle uses nearly all its propellant to reach Earth orbit, necessitating an orbital depot for lunar missions. Tanker Starships must launch individually, dock with the depot, and transfer fuel before the final lander departs. Each launch represents a full mission, making the total count a critical factor in cost and schedule.

The discrepancy arises from different assumptions about vehicle capability. NASA's estimate appears based on the current Starship lift capacity. Musk's lower figure assumes a more capable version of the rocket. The amount of propellant delivered to orbit and the losses during transfer determine the number of tankers needed. Cryogenic fuel and oxygen boil off slowly in space, further affecting the total. Berger noted that even with two launches per week by the end of 2027, filling the depot to the panel's 22-launch standard would take three months.

Musk has previously contested similar figures. In 2021, he rejected a government estimate of 16 launches, calling it "extremely unlikely" and suggesting eight would be the maximum. The outcome depends on hardware SpaceX has not yet fully tested. The company plans to use its upgraded V3 Starship for refueling operations. Precourt acknowledged that Artemis IV involves "a large number of firsts." He also praised NASA Administrator Jared Isaacman's team for working to clear obstacles for both SpaceX and Blue Origin.

The next step involves completing the V3 Starship development and executing the first orbital refueling demonstration. These tests will provide the data necessary to resolve the discrepancy between the panel's conservative estimate and SpaceX's projected performance. The results will determine the final launch schedule for the 2028 crewed mission.