NASA estimates 22 launches needed for lunar return

For residents of New England and space enthusiasts across the country, the timeline for seeing humans walk on the Moon again just became more complex. The core challenge is not just building a rocket, but filling it with enough fuel to reach the Moon and return. A new estimate reveals that this process may require as many as 22 separate launch missions from Earth. This figure represents a substantial increase in logistical complexity compared to earlier, more optimistic projections.

The path to this updated number has been marked by uncertainty and shifting expectations over the last several years. In 2023, Lisa Watson-Morgan, who served as the director of NASA’s Human Landing System, indicated that the agency had a general understanding of the requirements but was hesitant to pin down an exact figure. She described the expected number of launches as being in the high single digits to the low double digits. This earlier estimate implied that roughly a dozen flights would be sufficient to build up a fuel depot in low-Earth orbit.

Under that earlier scenario, SpaceX would launch one primary vehicle to serve as the depot and approximately eleven other vehicles to act as tankers. These tankers would deliver liquid oxygen and methane propellant to the depot. The goal was to fully load the main lander for its journey to the lunar surface and back to lunar orbit. Other officials at the time suggested the number might be in the high teens, but the prevailing hope was that rapid improvements in rocket performance would keep the total count lower.

The strategy relied heavily on the assumption that SpaceX could dramatically improve the lift capacity of the Starship vehicle. If the rocket became more efficient, fewer tanker flights would be needed to achieve the same amount of stored fuel. This efficiency gain was critical to keeping the program on track for a lunar landing within the current decade. However, recent discussions among NASA officials suggest that this improvement may not arrive soon enough to meet those tight deadlines.

On Thursday, the NASA Aerospace Safety Advisory Panel convened for its quarterly meeting to discuss various risks associated with the Artemis Program. Charlie Precourt, a former NASA astronaut and member of the panel, addressed the specific challenges of landing humans on the Moon. During his presentation, he highlighted the emerging consensus that the number of required launches is trending higher than previously estimated.

The new estimate of 22 launches reflects a more conservative view of the current capabilities of the launch vehicle. It accounts for the reality that each tanker flight carries a limited amount of propellant. To reach the Moon, the lander must be fueled in orbit, a process that requires multiple rendezvous and transfer operations. Each of these operations introduces potential points of failure and demands precise coordination between multiple spacecraft.

This shift in planning parameters has significant implications for the schedule. If the number of required launches increases, the time needed to complete the refueling process also grows. This could push back the window for crewed lunar missions. The Artemis Program aims to return astronauts to the Moon this decade, but the margin for error in the launch schedule appears to be shrinking as the technical requirements become clearer.

The situation also highlights the interdependence between NASA and its commercial partners. The success of the program now depends heavily on the rate at which SpaceX can deliver reliable, high-capacity launches. Any delays or performance shortfalls in the Starship vehicle will directly impact the number of flights required to support a crewed mission. This creates a feedback loop where engineering improvements must outpace the schedule to keep costs and risks manageable.

As the program moves forward, the focus will remain on reducing the number of flights through hardware upgrades. Engineers will likely continue to work on increasing the payload capacity of the launch vehicle. However, until those improvements are proven in flight, the planning assumption will remain at the higher end of the spectrum. This means that mission designers are now building their timelines around a scenario that requires nearly twice as many launches as the most optimistic early estimates.

For the public, this update serves as a reminder that space exploration is a process of iterative refinement. The numbers change as the technology evolves. While the goal of returning to the Moon remains unchanged, the method for getting there is becoming clearer, if also more demanding. The coming months will see further analysis as the agency finalizes its operational plans based on this new data.