NASA Safety Panel Estimates 22 Starship Flights for Lunar Refueling

The number of rocket launches required to reach the Moon has jumped significantly.

NASA has long shielded this specific figure, treating the count of Starship vehicles needed to refuel a lander in Earth orbit with the secrecy usually reserved for national security codes. The agency has historically declined to commit to a firm number, arguing that the total fluctuates based on the rocket's evolving capabilities. During a meeting of the NASA Aerospace Safety Advisory Panel on Thursday, member Charlie Precourt, a former astronaut, addressed the risks associated with the Artemis Program. Precourt provided a specific estimate for the quantity of Starship launches necessary to fuel a lander in low-Earth orbit, enabling a journey to the Moon, a landing, and a return to lunar orbit. That figure is 22.

For years, the answer to this question has been a moving target. In 2023, the then-director of NASA’s Human Landing System, Lisa Watson-Morgan, stated, “We have a general idea, but I’m reluctant to say exactly what that is.” She later suggested a range spanning from the high single digits to the low double digits, which would imply a requirement of roughly a dozen launches. Other officials have cited figures in the high teens.

The logistics involve a specific sequence of orbital maneuvers. SpaceX must first launch a dedicated depot Starship, followed by a series of tanker vessels, which transfer liquid oxygen and methane propellant to the depot. The plan has always been that increasing the rocket's lift capacity would reduce the number of tanker flights required to top off the depot for a lunar voyage. However, some NASA officials have expressed concern that these improvements are not materializing quickly enough. Consequently, there are questions regarding whether the vehicle can play a meaningful role in returning humans to the Moon for NASA as part of Artemis this decade.

The projection of 22 launches underscores the immense logistical challenge facing the program. The sheer volume of flights required to assemble the necessary fuel for a single lunar mission remains a significant hurdle for the agency's timeline.