Successful In-Space Propellant Transfer Demonstration

On 14/03/2024, SpaceX conducted the third Integrated Flight Test (IFT-3) of its Starship spacecraft, during which the company carried out a cryogenic propellant transfer demonstration while the vehicle was in space during a suborbital coast phase. The test launched from SpaceX’s Starbase facility in South Texas and achieved several mission objectives, including payload door operation and a tank-to-tank liquid oxygen transfer experiment. NASA confirmed that the demonstration involved transferring cryogenic liquid oxygen between Starship tanks as part of technology development for future deep-space missions. The propellant transfer demonstration aimed to move roughly 10 metric tons of cryogenic liquid oxygen from a header tank to the main tank inside the Starship upper stage. This operation took place in microgravity conditions during the vehicle’s coast phase, testing the ability to manage super-cooled propellant in space. The experiment formed part of a NASA Tipping Point technology development effort designed to mature in-space refueling capabilities. The demonstration was reported as successful by SpaceX officials pending detailed post-flight analysis of telemetry data. The test was conducted under a NASA partnership valued at approximately $53.2 million, focused on advancing cryogenic fluid management and in-space refueling systems. These technologies are required for Starship’s planned role in NASA’s Artemis program, where the spacecraft is expected to transport astronauts to the lunar surface. Because Starship consumes most of its propellant reaching Earth orbit, refueling in space is necessary to enable missions carrying heavy cargo or crew beyond low Earth orbit. NASA has identified cryogenic propellant transfer as a critical capability for sustained missions to the Moon and future exploration goals. Although the IFT-3 mission ended with loss of the vehicle during reentry, the flight provided data on multiple objectives, including the in-space propellant transfer test. NASA and SpaceX teams later reviewed the data to evaluate performance of the liquid oxygen transfer system and related cryogenic fluid technologies. The demonstration marked one of the first attempts to move large quantities of super-cooled propellant inside a spacecraft while in space, supporting development of orbital refueling architectures planned for lunar and Mars missions.