Moon Landing Requires 22 Rocket Flights

SpaceX and NASA have historically kept the exact number of rocket launches needed to support a Moon landing under wraps, treating the figure with a secrecy that might be more fitting for a nuclear code. However, that veil of uncertainty was partially lifted this week, revealing a new estimate that suggests the logistical hurdle for the Artemis program is significantly higher than many had hoped.

During a quarterly meeting on Thursday, the NASA Aerospace Safety Advisory Panel discussed the risks associated with returning humans to the lunar surface. Panel member Charlie Precourt, a former NASA astronaut, spoke on the topic and provided insight into the current planning figures. While the agency has long avoided pinning down a specific count, this recent discussion points to a requirement of 22 Starship launches to fully fuel a Starship-based lunar lander in low-Earth orbit.

The number has been a moving target for years, with NASA officials consistently deferring to a cautious approach. In 2023, Lisa Watson-Morgan, who served as the director of NASA’s Human Landing System, told Ars that the agency had a general idea but was reluctant to commit to an exact number. She later described the requirement as being in the “high single digits to the low double digits.” This earlier estimate implied roughly a dozen launches, a substantial but manageable number for SpaceX to execute.

To achieve the earlier estimate of around twelve launches, SpaceX would need to launch one “depot” Starship to orbit, followed by eleven “tanker” Starships to load it with liquid oxygen and methane propellant. This process is necessary to ensure the lander has enough fuel to fly to the Moon, land, and return to lunar orbit. Some other officials have even suggested the number could be in the “high teens,” reflecting the uncertainty surrounding the vehicle’s efficiency.

The hope has always rested on SpaceX dramatically improving the lift capacity of Starship. If the rocket can carry more fuel per flight, the number of tanker launches required to fill the depot would drop significantly. This efficiency gain was critical to making the Starship rocket play a meaningful role in NASA’s Artemis goals within this decade. The technology was expected to evolve rapidly, reducing the logistical burden on the ground.

However, concerns are growing among some NASA officials that this dramatic improvement may not arrive soon enough. There is a fear that the lift capacity improvements will not materialize in time for Starship to be a viable option for this decade’s Moon landing. If the number of required launches remains high, the timeline for human return to the Moon could be stretched or complicated by the sheer volume of orbital refueling operations needed.

The stakes are high for both the agency and the contractor. A higher launch count means more time, more cost, and more risk in orbital operations. It also tests the limits of SpaceX’s current launch cadence and Starship’s operational maturity. The new estimate of 22 launches places the Artemis program in a more challenging position than the optimistic projections from a few years ago suggested.

As NASA continues to navigate these logistical complexities, the transparency provided by the Advisory Panel offers a clearer, if less favorable, picture of the path ahead. The agency must now decide how to proceed with a higher number of required flights, balancing the desire for a timely Moon landing with the realities of current rocket performance.

For now, the focus remains on whether SpaceX can close the gap between current performance and the ideal efficiency needed to lower that number. Until then, 22 stands as the benchmark that defines the scale of the orbital logistics challenge facing the Artemis program.