The first U.S. crewed moon missions since NASA’s Apollo program in the 1960s and 1970s promise more than flags and footprints: Artemis, the space agency’s ambitious plan for lunar return, envisions regular human voyages to the moon for decades to come. But Artemis will have to wait a bit longer to begin that journey with astronauts because NASA has announced delays for the program’s next major launches.
Following a successful uncrewed test flight in late 2022, the agency had planned to launch a crewed lunar flyby mission called Artemis II in November 2024. In a press briefing last Tuesday, NASA officials revealed that because of various hardware issues, the mission is delayed until September 2025. Artemis III—the program’s first crewed lunar landing—has slipped as well, pushed back to September 2026. Artemis IV, another crewed landing, is still on course for a launch sometime in 2028, the officials said.
Artemis’s delays stem from its complexity, which arises in turn from the program’s history and ambition. Some of its key vehicles—the Space Launch System (SLS) rocket and Orion crewed spacecraft—have been in the works for well more than a decade: these vehicles trace their origins to NASA’s attempts to devise a new human spaceflight architecture after the 2011 retirement of the agency’s space shuttle fleet. NASA is also shoring up Artemis against fickle political winds by linking it to international diplomacy and burgeoning economic activity in space. In a departure from the Apollo era, Artemis is more reliant on international partners and private companies to deliver space station components, rockets, space suits and lunar landers.
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“If you look at Artemis [components]—say, a half-dozen major items—every one of them is a challenging systems engineering problem. But then, stepping back, you have to have this ensemble also come together,” says George Washington University professor Scott Pace, who formerly served as executive secretary of the National Space Council during the Trump administration, which formulated Artemis and made it official U.S. policy.
News of the delays came as little surprise to Pace and other space policy experts. Since its inception in 2019, Artemis has seen several rounds of rescheduling. Complex NASA programs—crewed and uncrewed alike—regularly run into delays and cost overruns because the agency seeks to minimize the risk of technical failures. But such delays are especially common in human spaceflight, where failures can be deadly. In 1986, for instance, pressure to maintain a fast-paced launch schedule contributed to the loss of the space shuttle Challenger and the deaths of the seven NASA astronauts onboard.
“It makes me, with my historian’s eye, feel like they’re doing the right thing,” says Jennifer Levasseur, a curator at the Smithsonian Institution’s National Air and Space Museum. “If NASA says in advance, ‘We need extra time on this,’ there is a really solid reason they need extra time.”
Fly Me to the Moon
The delays for Artemis II, a flyby moon mission much like that of Apollo 8, primarily stem from cautions over the safety of the four-person crew: NASA astronauts Reid Wiseman, Christina Koch, Victor Glover and Jeremy Hansen.
According to NASA, the agency is carefully evaluating batteries onboard Orion that are related to the launch abort system. Officials are further along in assessing another issue: a design flaw in one of the valve circuits in Orion’s life support system. In the worst case, this flaw could lead to a malfunction that would allow dangerous amounts of carbon dioxide to build up in the capsule’s air supply. NASA officials have opted to replace these circuits on the Orion spacecraft that is slated for Artemis II. But because of these parts’ location within the already assembled vehicle, technicians must undo much of their previous work to make that repair.
“The access to those bays is going to take us quite a bit of time to get to. Every connector that we touch as part of that replacement operation will have to be tested after we’re done,” said Amit Kshatriya, deputy associate administrator of NASA’s Moon to Mars program, during the press briefing. “We know how to fix it. We just need to make sure we take the time to do it according to the workmanship standards that we expect.”
NASA is also still puzzling over data from the fiery atmospheric reentry of Artemis I. As the mission’s Orion spacecraft screamed through Earth’s upper atmosphere, the craft’s heat shield shed some of its char with unexpected ease, leaving behind small but problematic pitting. Orion’s heat shield is meant to shed its outer layers and draws on well-known technology: the key ablative material within it, called Avcoat, was also in the heat shields for the Apollo crew capsules. Orion’s heat shield is manufactured differently than Apollo’s heat shields were, however, and it’s also being subjected to different conditions.
Unlike Apollo’s hardware, when Orion capsules returning from the moon encounter Earth’s atmosphere, they’re meant to initially skip off it—like a flat rock thrown across a pond surface—before continuing the plunge. This maneuver helps slow down the capsule more gently while also letting mission controllers more easily guide the spacecraft to a consistent landing site.
It also appears to subject Orion’s heat shield to unanticipated stresses, however. In the briefing, Kshatriya said that most of the material that came off the heat shield was shed during the spacecraft’s first skip maneuver. He also emphasized that the Artemis I Orion craft’s heat shield performed well overall and would have posed no risk to any astronauts onboard.
Getting to the Surface
Adding to the challenges facing Artemis, its missions get dramatically more ambitious starting with Artemis III, the program’s first lunar landing attempt.
The mission will start similarly to Artemis II, with a crew of four astronauts launching in an Orion spacecraft atop an SLS rocket. Once it gets near the moon, however, the Orion craft will dock with a preplaced upper stage of Starship: the massive, fully reusable rocket being developed by SpaceX. Two crew members will then enter Starship, leaving Orion behind in lunar orbit as they ride the rocket down to the moon’s surface. Once their surface operations are complete, the astronauts will ascend on Starship to rejoin their crewmates onboard Orion for the return to Earth.
Artemis III has a lot of moving parts, in other words—and it can’t proceed until all that hardware is ready for flight.
For one, NASA needs space suits so that its astronauts can conduct moonwalks on the lunar surface. In September 2022 the agency awarded the mission’s space suit contract to Axiom Space, a Houston, Tex.–based firm that has been flying commercial missions to the International Space Station since 2022.
And then there’s Starship itself. The vehicle has had two integrated test flights so far, and both ended in fire and flame. These explosive losses didn’t come as a surprise, given SpaceX’s fast, failure-tolerant approach to refining its rocket designs. Starship must run a truly daunting gauntlet of additional tests, however, before it attempts to ferry astronauts to the lunar surface and back.
First, SpaceX will need to build and fly however many Starships it takes to reliably launch the vehicle into orbit around Earth. The company will also need to demonstrate propellant transfers between two in-orbit Starships, which has never been done before. Such orbital refueling is critical to Artemis as it is currently conceived. To have enough propellant for a round trip to the lunar surface, the Artemis III Starship will have to refuel in Earth orbit before departing for the moon.
This step alone demands many additional Starship flights, one right after the other, to supply the spacecraft with fuel. At last week’s briefing SpaceX representative Jessica Jensen said that the lunar Starship for Artemis III will need roughly 10 other Starship flights’ worth of fueling before it can go beyond Earth orbit.
SpaceX will need to tiptoe through this elaborate orbital choreography at least once before Artemis III proceeds. Under its contract with NASA, the company must conduct an uncrewed test landing of Starship on the moon in the lead-up to Artemis III. SpaceX is currently targeting this test for sometime in 2025, according to Jensen.
It’s difficult to overstate just how much Starship will offer Artemis—and space exploration as a whole—if the vehicle works as promised. According to SpaceX, a single Starship could land at least 100 metric tons of cargo on the moon. That’s more payload at once than all humankind has soft-landed on the moon so far, including the six Apollo landers and associated hardware. But to realize such a staggering advance, Starship will likely first need to fly dozens of times as SpaceX irons out the rocket’s many remaining kinks.
“We should not mince words about how many risks for Artemis’s schedule NASA has taken on by going with SpaceX,” says Casey Dreier, chief of space policy at the Planetary Society. “If it works, even if it’s late, it has huge ramifications. But of course, anything so technically ambitious is going to run into problems.”
What Makes a Sustainable Program?
Experts say that the delays will do little to quell Artemis’s momentum. In fact, the program’s complex, unwieldy architecture may be one of the key reasons for its endurance. Artemis exists as it does primarily because its components are politically palatable.
For example, the SLS rocket has been in development since 2011, and has faced criticism over its exorbitant cost throughout that time. Much of that cost, however, is linked with its reliance on—and bolstering of—U.S. aerospace supply chains with ties going back to the space shuttle, an approach that serves both technological and national security interests. And despite an eye-watering price tag in excess of $2 billion per launch, policy makers have stood by the SLS program for providing the U.S. with a publicly owned heavy-lift capability. “Never has there been such a difference between the level of critiques and their profound ineffectiveness on a program than [what] I’ve seen with SLS,” Dreier says. “Never once has there been as much as a waver in political support.”
Similar considerations extend to other pieces of Artemis, too. NASA is also working on Gateway, a small lunar space station that the agency will begin launching pieces of in the lead-up to Artemis IV, which is currently scheduled for September 2028.
Gateway isn’t technically necessary for the initial Artemis missions but has helped attract crucial early buy-in from international partners, which has arguably boosted Artemis’s prospects as a whole. On January 7 NASA announced that the United Arab Emirates will be contributing an airlock to the station and thus joining the European Space Agency, Canada and Japan as a Gateway contributor. “There are political pieces and technical pieces that come together in this ballet,” Pace says.
And along the way, NASA has used Artemis as justification to support technologies that will prove essential for any future crewed mission to Mars. Historically, advanced capabilities such as on-orbit refueling haven’t enjoyed much political support from the U.S. Congress. But under the auspices of Artemis, NASA is investing in that technology. SpaceX’s Starship relies on the method, and so does another lunar lander that the rival aerospace company Blue Origin is building for the Artemis V mission.
“What's at stake here is humans to Mars,” Dreier says. “In some ways, whether or not Artemis happens in 2026 or 2027—or even in the 2020s—is kind of outside of the point, considering the implications if they successfully pull this off.”