How a Boom in Mega Rockets Will Get Astronauts Back on the Moon

If you want to get to the moon, you need a mega rocket. NASA’s got one, in the form of the Space Launch System (SLS), a 32-story monster with a record setting 4 million kg (8.8 million lbs.) of thrust. The rocket launched on its maiden voyage in November, placing an uncrewed Orion spacecraft in lunar orbit—a mission dubbed Artemis I. Crewed missions are set to follow soon; the question is how soon.

The space agency has promised that Artemis II will carry four astronauts on a journey around the far side of the moon as early as next year, with Artemis III sticking a crewed lunar landing in 2025 or 2026 and further Artemis missions to follow at one-year intervals after that. To a lot of people that felt like overpromising—especially considering the SLS has been in development in one form or another since 2004, with just the one flight so far, at a cost of more than $4 billion, to show for it. If you don’t have plenty of rockets, you can’t have plenty of moon trips.

As NASA reports this week, however, those rockets are very much in the pipeline, with fast-paced construction now underway on the SLS hardware needed for Artemis II, III, and IV at no fewer than five different assembly plants around the country. Slow off the mark for its very first launch, the SLS product line is now humming, making the prospect of Artemis II returning astronauts to the lunar vicinity in 2024 for the first time since 1972 look better and better. And the same goes for the missions that are planned to follow.

The principal construction on the multiple rockets is taking place at NASA’s Michoud Assembly Facility in New Orleans, where the 21-story core stages of no fewer than three SLS rockets are currently in various stages of assembly. “Michoud is humming with activity,” said facility director Lonnie Dutreix in a statement. “Everywhere you look you see rocket hardware.”

Michoud is not remotely alone. The core stage of the SLS is powered by four RS-25 engines—the same ones used on the space shuttles—and at the Stennis Space Center in southern Mississippi, a dozen of them, for Artemis III, IV, and V, are in various stages of development. Meantime, two facilities—at Cape Canaveral and in Decatur, Ala.—are hard at work building the four-and-a-half-story tall second stage of the SLS for both Artemis II and III. And at Northrop Grumman’s assembly facility in Utah, the solid rocket boosters that flank the core stage of the SLS are already completed for Artemis II and III and under construction for Artemis IV.

The building boom is reminiscent of the Apollo era’s Saturn V rocket, nine of which launched crews to the moon in just a four-year window from 1968 to 1972. The Kennedy Space Center’s Vehicle Assembly Building was sometimes home to two Saturn V’s at a time—one ready to roll out to the pad and one on deck for the mission that would follow. Nobody pretends that the SLS will fly at the same sprint—that one-a-year pace is still the most NASA’s current budget can support. Still, more than 20 years in the making, the SLS series is deep in its development phase, bringing the space agency’s promise of a new lunar era closer to imminent reality.

“NASA is on the brink of a new age of deep space discovery,” said SLS program manager John Honeycutt in a statement. The construction team, he adds, “is more focused than ever to manufacture and produce SLS rockets for Artemis missions that will put boots on the moon for decades to come.”