By Basant El-Faramawy
NASA's Aerospace Safety Advisory Panel estimates that SpaceX's Starship rocket could require up to 22 in-orbit refueling missions before it has enough propellant to travel to the Moon for the Artemis IV mission in 2028. The figure highlights the complexity of orbital refueling, a maneuver never before attempted at this scale.
Musk disputes refueling count
Elon Musk challenged the panel's estimate on X, stating the actual number would be closer to six to eight refueling flights. The SpaceX chief executive said the plan involves launching a Starship to serve as an orbital fuel depot, followed by multiple tanker flights to fill it, before a final crewed Starship docks and takes on the fuel needed for the lunar journey.
Artemis III and IV timelines
NASA aims to use Starship for the Artemis III mission next year, which will test in-orbit docking with the crewed Orion spacecraft. The agency then plans to land astronauts on the lunar surface during Artemis IV in 2028, using either SpaceX's Starship or a lander from Blue Origin. For Artemis IV, astronauts will launch on NASA's SLS rocket from Kennedy Space Center, rendezvous with a fueled Starship in Earth orbit, and proceed to the Moon.
Upcoming flight tests
SpaceX is preparing for a Starship flight test expected next week that will demonstrate aspects of in-orbit propellant transfer. The company also targets a "profound technology milestone" by catching both stages of the rocket during Starship Flight 15. Musk said success is more likely than not on early flights, with a steady cadence of attempts through the end of this year and accelerating in 2027.
