SpaceX's first Starship test flight in April could seriously delay NASA's Artemis program, which aims to develop a sustainable way to land humans on the moon, according to a report from the U.S. Government Accountability Office (GAO). NASA's Artemis III flight is currently scheduled to depart in 2025, and the GAO report noted that several parts of SpaceX's Human Landing System (HLS) development are taking longer than NASA projects typically take, based on average historical data.
Other key constraints to a 2025 launch include delays in a new spacesuit designed by AxiomSpace for use on the moon.
The mission architecture of SpaceX's Starship HLS lunar lander involves launching a fuel reservoir into space and then filling it up. Once the fuel depot is filled with fuel, the HLS lander will dock with it and begin its journey to the moon. According to the U.S. Government Accountability Office, demonstrating propellant transfer in space would require successfully launching Starship into orbit. SpaceX's April Starship test flight ultimately delayed key demonstration work.
The report outlines SpaceX's April Starship test, which was originally planned to successfully demonstrate Starship's ascent, flight of the second stage superimposed on the first stage, and interstage separation. However, company officials informed NASA that a fire inside the rocket caused its autonomous flight termination system to destroy the rocket and end the test prematurely.
The U.S. Government Accountability Office said SpaceX and NASA have postponed multiple "critical events" of the HLS program until 2024, with eight of the 13 critical events delayed by six to 13 months. SpaceX must complete eight key activities between November 2023 and Artemis III flight, and the assessment comes ahead of this month's orbital test flight that demonstrated the rocket's stage separation and the ignition of the second-stage Starship engine.
The delays could also have safety implications for the HLS program because they would squeeze the timeline NASA must adhere to to ensure Starship meets human spaceflight requirements, the U.S. Government Accountability Office (GAO) said. According to NASA and HLS officials, SpaceX must prove that Starship can reach orbit before it can move forward with other milestones, such as pre-Artemis III unmanned testing and propellant transfer in space.
However, HLS officials believe that a successful test flight will speed up SpaceX's design process and allow the company to finally lock in the Starship design. After the April test flight, NASA officials were unable to determine whether Starship could complete the mission before the December 2025 Artemis III deadline, and the HLS program schedule would need to be adjusted after April.
Key areas of technical work that could cause delays include the Raptor engines and fuel depots. Running the Raptor engine at a certain performance level is key to engine certification. If it still fails certification, then a replacement engine system cannot be developed in a timely manner. Speaking with the GAO, SpaceX representatives said they collected valuable fuel tank data and other operational data following the April test. They added that SpaceX has assembled and tested hundreds of engines as part of an iterative design approach.
Regarding on-orbit fuel storage systems, the report outlines that project documents show SpaceX has made little progress in maturing these technologies. The U.S. Government Accountability Office said some of the systems SpaceX needs to develop include:
These systems include docking sensors and mechanisms (used to identify, locate and physically align the HLS Starship and refueling Starships for fluid transfer); propellant measurement (used to measure the amount of propellant in the tank and how much propellant is transferred); and storage capabilities to reduce fuel loss in space.
The report was written ahead of SpaceX's Starship test in November, which successfully completed stage separation and engine ignition. Since then, footage from the Texas facility shows a lot of activity as SpaceX prepares for its next Starship test flight.