8 vs. 22: Musk Counters NASA Panel's Lunar Fueling Estimate
The CEO argues that only six to eight tanker flights are required for Artemis IV, while a former astronaut on a safety board warns the number is closer to 22.
By John Ferrari ·
The timeline for sending astronauts to the Moon in 2028 now hinges on a dispute over fuel logistics. NASA’s Aerospace Safety Advisory Panel (ASAP) warned that landing a crew requires approximately 22 Starship launches to refuel the lander in orbit. SpaceX CEO Elon Musk publicly rejected that figure, stating the actual requirement will be much lower.
The conflict surfaced during the panel’s quarterly public meeting on Thursday. Charlie Precourt, a former NASA astronaut and panel member, identified lunar lander fueling as a primary risk for the Artemis IV mission. "We need to keep our eyes on numerous required fuelings for the lander," Precourt said. He cited the most recent estimate at around 22 flights.
Musk responded to a social media post from Ars Technica reporter Eric Berger, who had shared Precourt’s remarks. "That’s way too high," Musk wrote. "Actual number will be more like 6 to 8." The discrepancy stems from differing assumptions about Starship performance. NASA’s estimate appears based on the vehicle's current lift capacity, while Musk’s lower range assumes a more capable, upgraded version of the rocket.
The logistical challenge arises because Starship consumes nearly all its propellant reaching Earth orbit. It cannot proceed to the Moon without an orbital transfer. SpaceX’s plan involves launching a storage depot first, followed by tanker Starships that dock and transfer fuel. Once the depot is full, the crewed lander launches, refuels, and departs. Each additional tanker flight increases the time, cost, and potential failure points before a crew leaves Earth.
Even with SpaceX aiming for two launches per week by the end of 2027, the higher estimate presents a scheduling bottleneck. Berger calculated that filling the depot with 22 flights would take about three months. The final count also depends on propellant boil-off, as the cryogenic fuel and oxygen lose mass while waiting in orbit and during transfers.
Musk has previously disputed higher launch counts. In 2021, he called a government estimate of 16 launches "extremely unlikely" and predicted a maximum of eight. The company intends to conduct these refueling operations with its upgraded V3 Starship, hardware it has not yet fully flown. Precourt noted that Artemis IV contains "a large number of firsts." He also praised NASA Administrator Jared Isaacman for clearing obstacles for both SpaceX and Blue Origin, whose Blue Moon lander does not require orbital refueling for its initial mission.
