NASA has started the final assembly of the Space Launch System for Artemis 3, moving the rocket’s core stage into the Vehicle Assembly Building at Cape Canaveral. The next big step is fitting four RS-25 engines, the upgraded descendants of Space Shuttle hardware that still do a lot of the heavy lifting for America’s moon rocket.
The core stage is now standing vertically in High Bay 2, where technicians are preparing the handoff to the engine section. After the engines go in, NASA will move the stage to High Bay 3 for the final stacking with the Orion spacecraft. That’s the point where the rocket starts looking less like a collection of very expensive parts and more like a launch vehicle.
Artemis 3 launch target and rocket size
Artemis 3 is still slated for the second half of 2027, and the numbers are as brutal as ever: about 98 meters tall in full configuration, with a fueled mass of roughly 2,600 tonnes. For comparison, that puts SLS in the same rarefied club as the heaviest launchers ever built, even if the program has spent as much time in schedule limbo as in the clean room.
- Core stage: already upright in Vehicle Assembly Building High Bay 2
- Next step: installation of four RS-25 engines
- Final stacking: High Bay 3 with Orion
- Planned launch window: second half of 2027
Artemis 3 mission profile has shifted
That 2027 mission is no longer the lunar landing NASA originally sold. Delays to the landing systems being developed by SpaceX and Blue Origin forced the agency to reshape Artemis 3 into an orbital test of rendezvous and docking, potentially with one or even two landers. It’s a more cautious script, but also the practical one: prove the machinery works before asking astronauts to trust it on the Moon.
If those tests go well, NASA is already looking past Artemis 3 to Artemis IV in 2028, where a crewed lunar landing is now the real target. In other words, the rocket is moving; the program is still catching up.