SpaceX's proposed concept of operations for the Starship lunar lander under the Human Landing System (HLS) program involves multiple launches of the Starship/Super Heavy system, which will require rapid turn around of both Starship launch facilities.
As SpaceX reviews the outcomes of its 2nd test flight, a NASA official has voiced concerns over the number of launches needed for the spacecraft's involvement in Artemis lunar landings.
During a presentation of the NASA Advisory Council’s Human Eploration and Operations Committee on November 17, Lakiesha Hawkins, Assistant Deputy Associate Administrator in NASA’s Moon to Mars Program Office stated that the use of Starship for Artemis will require "in the high teens" of launches, a figure significantly higher than previous estimates.
SpaceX's proposed concept of operations for the Starship lunar lander under the Human Landing System (HLS) program involves multiple launches of the Starship/Super Heavy system.
This includes placing a propellant depot into orbit, followed by multiple launches of tanker versions of Starship to transfer methane and liquid oxygen propellants into the depot. Subsequently, the lander version of Starship will rendezvous with the depot to fill its tanks before embarking on the mission to the moon.
The high number of launches is driven by concerns about boiloff, the loss of cryogenic liquid propellants at the depot. The exact number of launches required for this process has been a topic of debate since Starship was selected by NASA for the HLS award in 2021.
"In order to be able to meet the schedule that is required, as well as managing boiloff and so forth of the fuel, there’s going to need to be a rapid succession of launches of fuel" - Lakiesha Hawkins, Assistant Deputy Associate Administrator in NASA’s Moon to Mars Program Office
The proposed launch schedule will necessitate launches from both SpaceX's current Starship pad in Starbase, Texas, and the one under construction at Kennedy Space Center's Launch Complex 39A with Hawkins mentioning a "six-day rotation" for launches from both sites to meet the demanding schedule.
Critics of NASA's decision to select Starship for HLS have pointed to the high number of launches as a potential weakness in the overall architecture.
The Government Accountability Office, in response to protests by Blue Origin and Dynetics, noted that SpaceX required 16 launches for a Starship lunar lander mission.
Elon Musk, SpaceX's CEO, disagreed with this assessment, stating in an August 2021 social media post that the need for 16 launches was "extremely unlikely." He suggested a maximum of eight tanker launches might be required to fuel the Starship lander, possibly as few as four.
The ongoing development of the Starship lander is considered critical for the Artemis 3 mission, but there are various factors that will contribute to the mission's success including the development of new spacesuits by Axiom Space, and the addition of a docking port on the Orion spacecraft.
NASA has reportedly considered changing Artemis 3 to a Lunar Gateway mission, with Artemis 4 becoming the landing mission; but at this time no official decision to change the current plans have been made.