NASA Administrator Jared Isaacman recently announced a significant restructuring of the Artemis program, and how the agency intends to return astronauts to the moon.
The new plan shortens the time between missions and redraws the map of which launches will achieve various program milestones. Nothing will change for Artemis 2, which may lift off in a matter of weeks, carrying four astronauts on a 10-day flight around the moon and back to Earth. Every mission after Artemis 2, however, has been adjusted.
Isaacman announced the changes during a press conference on Feb. 27, citing unacceptable wait times between missions for Artemis’ Space Launch System (SLS) rocket and an increased risk of relying on unproven technologies to carry out mission-critical objectives like landing astronauts safely on the lunar surface.
The Artemis 2 SLS is currently undergoing repairs in the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center in Florida, with a potential rollback to its launch pad in time for a launch window that opens April 1. Artemis 2 will bethe first crewed flight of the Orion spacecraft and the first return of astronauts to lunar space in more than half a century. Under the previous framework, it was meant to be followed by Artemis 3 in 2028, which would carry out the program’s first moon landing with astronauts aboard SpaceX’s Starship vehicle.
For Artemis 4, NASA planned to upgrade to the SLS Block 1B, which features a design powerful enough to launch elements of the Gateway space station intended for lunar orbit. Beginning with Artemis 4, NASA aimed to use the Gateway outpost around the moon for deep-space science and as an orbital layover stop where Orion and the program’s lunar lander could dock to transfer crews headed down to the surface. Gateway, however, is nowhere to be found in any of NASA’s recent Artemis updates.
Under NASA’s new plan, there will be no SLS Block 1B. In the hope of shortening launch cadences from the current 3.5-year interval to the desired 10 months, SLS is being standardized into a single configuration. Instead of relying on SLS’ current Interim Cryogenic Propulsion upper stage, NASA is reportedly considering converting United Launch Alliance’s Centaur V upper stage for use on SLS for all Artemis launches after Artemis 3.
The revised Artemis program is now targeting 2027 for the launch of Artemis 3, but instead of landing on the moon, the mission will fly to low Earth orbit for rendezvous and docking maneuvers with either or both of the Artemis program’s contracted moon landers — SpaceX’s Starship and Blue Origin‘s Blue Moon spacecraft — depending on their relative readiness for orbital missions.
NASA partnered with SpaceX for Starship to serve as the lander for Artemis 3 and 4 and contracted Blue Moon for Artemis 5. But the agency is now signaling that it’s ready to fly Artemis 3 with whichever lander can be made safely available when launch time rolls around.
With Artemis 3 turned into a lunar landing stepping stone around Earth, Artemis 4 has been tapped as the program’s first crewed landing on the moon, which NASA still hopes to accomplish in 2028, with a possible second moon landing that same year on Artemis 5.
It’s a major reshaping of Artemis’ original mission progression, but the plan has been purposed to maximize both crew safety and NASA’s chances of success, according to Isaacman. The shakeup doesn’t come without some sacrifice, though.
Gateway’s fate remains undetermined under NASA’s new plan. Many components of Gateway are already in various states of assembly, but there is now no rocket to launch them once they’re ready and no missions yet assigned to rendezvous with the proposed outpost. Congress advanced a revised NASA authorization bill on Wednesday (March 4) that supports many of Isaacman’s proposed changes to the Artemis program, but only requires he brief lawmakers on Gateway’s status within a few months’ of the bill’s passing.
If Gateway is on the chopping block, as seems likely, there is potential for its existing hardware to be repurposed for use in a possible base on the lunar surface, which has been a longstanding component of the Artemis program’s goals and NASA’s vision for a sustained human presence on the moon. One of the revisions in the authorization bill even grants the NASA administrator the freedom to “repurpose, reprogram, reconfigure, or reassign existing programs, platforms, modules, or hardware originally developed for other programs” in order to ensure that the space agency’s Artemis goals are successful.
Canceling future SLS upgrades also has implications for some of Artemis’ ground infrastructure, which is being built to support the larger rocket variant. To transfer the 322-foot-tall (98 meters) SLS Block 1 from the VAB to its launch pad, NASA uses the huge Crawler-Transporter 2 vehicle to traverse the distance with the rocket standing on its mobile launch platform (MLP). The MLP contains the SLS launch tower, which helps secure the rocket in place and provides the umbilicals that help fuel SLS before liftoff.
Previous block upgrades to SLS were substantial enough to require a separate MLP (Mobile Launcher 2) be built, rather than upgrading the existing platform. But in an update on March 3, NASA confirmed that “the agency is no longer planning to use the Exploration Upper Stage or Mobile Launcher 2.”
The contract for Mobile Launcher 2 was awarded in 2019, and has cost about $1.6 billion to date, about 98% of which has already been paid. Seven years later, the Mobile Launcher 2 is currently nearing completion outside the VAB, but it now may never realize its originally intended purpose. And relying on a single MLP to support Artemis launches less than a year apart could cause a schedule jam. The SLS MLP required refurbishment from damage caused after the Artemis 1 launch in November 2022.
Preparing the existing mobile launcher for an Artemis 4 flight with a new Centaur V-based upper stage could take a year or more, because the work would go beyond normal post-launch refurbishment. Engineers would have to reconfigure upper-stage umbilicals, fluid and electrical interfaces, and control systems, then complete testing to certify the update for launching SLS.
Potentially losing Gateway, or having to halt construction and/or repurpose the hardware from Mobile Launcher 2, isn’t necessarily a total loss for NASA or the Artemis program, though. The agency has a long history of repurposing or evolving massive hardware for use on new or revised missions. Elements from both could be utilized to support Artemis or other future missions as NASA’s plans continue to evolve.
