Musk: 6 to 8 tankers will fuel 2028 Moon mission, not 22
The SpaceX CEO rejects a NASA safety advisory panel's figure for the 2028 Artemis IV mission, claiming orbital refueling requires far fewer tanker launches than previously modeled.
By Thomas Obasi ·
A sharp disagreement has emerged over the logistics of the 2028 Artemis IV Moon landing, with Elon Musk rejecting a NASA safety panel's projection of 22 Starship launches for orbital refueling. The dispute centers on the number of tanker flights required to fill a depot in Earth orbit before the crewed lander can depart for the lunar surface.
The conflict surfaced during the Aerospace Safety Advisory Panel's quarterly public meeting on Thursday. Panel member Charlie Precourt, a former NASA astronaut, cited the fueling process as a primary risk for the mission. "We need to keep our eyes on numerous required fuelings for the lander," Precourt said. "I think the last estimate is around 22 flights."
Musk responded to the remark after Ars Technica reporter Eric Berger shared it on X. "That's way too high," Musk wrote. "Actual number will be more like 6 to 8." The discrepancy stems from differing assumptions about Starship's performance. NASA's estimate appears based on current lift capacity, while Musk's lower range assumes a more capable vehicle that can deliver more propellant per launch.
The technical challenge arises because Starship consumes nearly all its propellant reaching Earth orbit. It must be refueled in space to reach the Moon. SpaceX's plan involves launching a storage tank, or depot, first. Tanker Starships then launch individually, dock, and transfer propellant. Once full, the lander launches, docks, refuels, and heads to the Moon. Each tanker flight is a full launch, making the total count a driver of cost, schedule, and risk.
Berger noted that even with two Starship launches per week by the end of 2027, filling a depot at the panel's 22-flight rate would take approximately three months. Propellant losses also factor into the calculation; Starship's cryogenic fuel and oxygen boil off while in orbit and during transfer. Musk has previously disputed higher counts, calling a 2021 government estimate of 16 launches "extremely unlikely" and predicting a maximum of eight tankers.
Precourt acknowledged that Artemis IV involves "a large number of firsts." The mission's success depends on hardware SpaceX has not yet fully tested, specifically the upgraded V3 Starship planned for refueling operations. Precourt also praised NASA Administrator Jared Isaacman's team for working to clear obstacles for both SpaceX and Blue Origin, whose Blue Moon lander does not require orbital refueling for its initial mission.
