NASA publishes Artemis IV Starship refueling architecture as launch estimates Vary

This is a new development in a story we reported earlier: NASA schedules Artemis III for 2027 as Moon landing rehearsal.

NASA published an Artemis IV refueling architecture graphic in late October 2026, detailing how SpaceX’s Starship Human Landing System will be loaded with propellant in Earth orbit before carrying astronauts to the Moon. The agency describes Artemis IV as its scheduled first crewed lunar landing mission, targeting early 2028 for four astronauts launching on the Space Launch System and Orion spacecraft—the same vehicles that carried four NASA astronauts around the Moon in April 2026. CITELIST: satnews.com, BGR

NASA’s illustrated sequence shows Starship tanker variants launching from Earth loaded with liquid methane and liquid oxygen for a propellant depot stationed in low Earth orbit. The tankers fill the depot before the lander arrives to take on propellant. Once the depot tanks are full, the uncrewed Starship HLS upper stage launches, docks with the orbital depot to receive a full propellant load, and initiates a trans-lunar injection burn toward lunar orbit, completing the in-orbit refueling sequence before the lander departs for the Moon.

SpaceX’s Artemis IV plan involves launching spacecraft into orbit to transfer fuel into the Starship Human Landing System. After refueling, the lander docks with Orion in Earth orbit and then propels the connected spacecraft into low lunar orbit.

Validating orbital refueling is a critical technical milestone for NASA’s broader Artemis lunar exploration roadmap. NASA must demonstrate successful refueling before full uncrewed lunar test flights proceed. Flight controllers and SpaceX engineers plan a first orbital cryogenic propellant transfer demonstration before full uncrewed lunar test flights begin.

The number of tanker flights required remains unresolved and is part of the debate over how many preliminary tanker flights a crewed lunar sortie will require. A summer 2021 Government Accountability Office audit estimated that the lunar architecture could require up to 16 launches. Charlie Precourt, a member of NASA’s Aerospace Safety Advisory Panel, cautioned during an October 2026 public meeting that fueling the lander could require as many as 22 launches, a higher estimate that exceeds the earlier Government Accountability Office projection.

SpaceX founder and Chief Executive Officer Elon Musk disputed the higher projection, saying on social media platform X that six or eight flights is closer to the true number. Musk’s lower figure reflects different engineering assumptions and directly contradicts the safety panel’s higher launch estimate.

The disagreement stems from different engineering assumptions about how much payload Starship can carry, how fast propellant boils off while waiting in orbit, and how well cryogenic fluid transfers between vehicles. Engineers disagree on propellant needs and tanker flight counts because of uncertainty about vehicle performance and cryogenic fluid handling in orbit. CITELIST: satnews.com

NASA restructured the Artemis timeline in February 2026, revamping Artemis III into a crewed Earth-orbit demonstration involving the Ship and Orion and delaying the crewed lunar return until 2028 as part of Artemis IV. The restructuring moved the crewed landing from Artemis III to Artemis IV, turning Artemis III into an Earth-orbit test. The agency awarded SpaceX the Starship HLS lunar lander contract in 2021, when the mission was still part of the upcoming Artemis III, and the original contract anticipated an Artemis III landing before the 2026 restructuring moved it to Artemis IV.

One month after NASA changed Artemis III in February 2026, the agency said lander readiness would decide which provider can safely ferry the crew between the surface and Orion in lunar orbit. The statement leaves open a change of provider if SpaceX’s lander is not ready, while SpaceX remains the contracted Artemis IV lander supplier. If SpaceX’s Starship fails to meet requirements, NASA could use Blue Origin’s Blue Moon lander instead for the Artemis IV landing, with NASA’s wording indirectly suggesting Blue Origin as a fallback provider for the crewed lunar return.

As of September 2026, Blue Origin’s Blue Moon lander was still in development, and the New Glenn rocket that would launch it toward the Moon had flown only three times. The New Glenn rocket exploded on the launchpad during an engine test in May 2026 as it prepared for its fourth launch, setting back Blue Origin even as its lander awaited the Artemis III Earth-orbit demonstration.

SpaceX must show that Starship is capable of reliable orbital flight before modifying the upper-stage Ship into the Starship HLS lander for the Artemis IV lunar touchdown. SpaceX must also show that Starships can move large amounts of cryogenic propellant between each other in orbit, since the lander needs that fuel to reach the Moon. Reliable orbital flight is one challenge SpaceX faces before the targeted 2028 launch date. If the Starship rocket and upper-stage lander are not ready for the targeted 2028 launch date, SpaceX’s involvement in the Artemis IV mission could be in jeopardy.

SpaceX plans to test docking the Starship lander with NASA’s Orion spacecraft for the first time during the Artemis III mission in Earth orbit, currently planned for 2027. Docking the lander with Orion must occur before crew transfer and lunar landing operations can proceed. Two other major challenges for SpaceX are showing that the lander can touch down safely on the Moon and launch back into lunar orbit, both required for the crew to return to Orion and then to Earth.

SpaceX’s Starship had flown a total of 14 times as of September 2026, and its upper-stage Ship reached orbit on the first attempt during the 14th test flight in September 2026. The first flight in 2023 ended in an explosion minutes after liftoff, an outcome the source attributes to SpaceX’s iterative test approach rather than the capability of Starship itself.

NASA anticipates launching Artemis III, a demonstration involving docking with both Blue Moon and Starship near Earth, by summer 2027, and is tracking toward a 2028 launch of Artemis IV, an actual lunar landing. The dates were presented at a NASA news conference on Friday, October 23, 2026, as part of a detailed overview of the return to the lunar surface as soon as 2028. Under the revised Artemis architecture, the Orion spacecraft will dock with the Starship lunar lander in high-Earth orbit before transiting to the Moon, a plan NASA acknowledged as one of several substantial architecture changes during the news conference. CITELIST: Ars Technica

In early 2026 meetings with NASA, SpaceX engineers pressed to drop the rule that Orion dock in a near-rectilinear halo orbit around the Moon. NASA canceled the Lunar Gateway earlier in 2026, solving the docking-orbit problem for SpaceX as part of broader architecture changes meant to help lander companies execute and speed up their plans.

NASA Administrator Jared Isaacman said the current path is achievable and that the agency has the mandate, resources, and stakeholder support to execute. Isaacman made the remarks during a lengthy NASA news conference on Friday outlining the return to the lunar surface, expressing confidence in the revised Artemis schedule.

Jeremy Parsons, NASA’s Artemis Program manager, said the agency is launching three of the most powerful rockets in the world on what is likely the most complicated launch campaign ever undertaken. Parsons made the remark during a press briefing about the Artemis III Earth-orbit test campaign.

NASA is aiming for the 14-day Artemis III Earth-orbit mission to happen in the summer of 2027, testing how versions of Blue Moon Mark 2 and Starship Version 3 landers rendezvous and dock with Orion. Artemis III will begin with Blue Origin’s lander launching atop New Glenn, followed by Orion lifting off on the Space Launch System, with the two spacecraft linking up in low-Earth orbit. The two spacecraft remain connected for about two days while the crew moves between them and conducts tests on Blue Moon. Starship Version 3 will launch atop the Starship rocket to join Orion in low-Earth orbit, where the two spacecraft will dock for up to two hours without the crew boarding Starship. CITELIST: Smithsonian Magazine

NASA and SpaceX will evaluate the Starship lander’s controllability, communications, and software performance during the Artemis III docked test, part of the 14-day Earth-orbit demonstration targeted for summer 2027. After undocking from Starship, Orion will spend up to five more days in orbit testing space suits, docking sensors, taking scientific measurements, and performing technology demonstrations crucial for future Artemis missions. These activities follow the two-day link-up with Blue Moon and the short Starship docked test. CITELIST: Smithsonian Magazine

Blue Origin’s accelerated approach employs three transfer stages that launch separately, connect in low-Earth orbit, and propel the Blue Moon lander into lunar orbit where it docks with Orion. The last transfer stage will take the Blue Moon lander into low lunar orbit, from which the lander will travel back and forth from the Moon before redocking with Orion, completing the Blue Origin crew delivery and return profile for the Artemis missions. Blue Origin’s plan includes four New Glenn launches and no spacecraft-to-spacecraft refuelings, per NASA’s October 2026 presentation. CITELIST: Ars Technica, Smithsonian Magazine

SpaceX will launch the upper-stage Starship Human Landing System lander to lunar orbit aboard the Starship rocket, and Orion will dock with it so two of four astronauts can transfer for the surface descent. The Starship lander would bring the crew to and from the Moon’s surface before returning them to Orion for the journey home. Under either provider scenario, two of four crewmembers board the lander while the rest remain in Orion, and the two astronauts who land would spend roughly a week on the Moon doing science before heading back to Orion in lunar orbit. CITELIST: BGR, Smithsonian Magazine

External experts are skeptical that NASA will achieve a moon landing in 2028 and believe China will beat the United States to the Moon, according to reporting cited by Smithsonian Magazine. The agency has already pushed back its lunar landing plans, with Artemis III now serving as a stepping stone toward that goal rather than the landing itself. Both SpaceX and Blue Origin are racing against the clock to meet the Artemis timeline, and following the New Glenn explosion in May 2026, SpaceX chief Elon Musk posted on X: “Rockets are hard.” CITELIST: Smithsonian Magazine, BGR