NASA's Space Launch System (SLS) first stage, powering humanity's return to the Moon, has successfully completed its seventh and penultimate test. Upper stage testing is slated for the coming months to prepare for the November 2021 launch.
The SLS, NASA's super-heavy lift vehicle developed since 2011, will launch crews to the Moon and potentially Mars. Its debut flight, Artemis I in November 2021, will send an uncrewed Orion capsule on a lunar orbit. This paves the way for Artemis II (crewed lunar orbit) and Artemis III (lunar landing).
Where do NASA and Boeing, the prime contractor, stand in SLS development?
The SLS first stage, standing 64 meters tall—the tallest booster NASA has ever built—will power the initial eight minutes of each Artemis mission. At NASA's Stennis Space Center near Bay St. Louis, Mississippi, engineers have conducted progressive tests under the Green Run program to ensure flawless performance.
Recently, teams loaded the core stage with cryogenic liquid hydrogen and oxygen for the seventh test: a "wet dress rehearsal." They verified fueling procedures and successfully drained the propellants, confirming system readiness.
The eighth and final test will fire the four upgraded RS-25 engines—evolved from Space Shuttle main engines—for over eight minutes. This ground-based hot fire promises a spectacular display from the grounded powerhouse.
The SLS Exploration Upper Stage (EUS) has passed its Critical Design Review (CDR). Experts validated its design for deep space rigors, prioritizing astronaut safety.
The review also confirmed robust testing protocols, supply chain reliability, and production plans. Boeing will build and assemble the stage in New Orleans before Green Run tests at Stennis Space Center.
With these milestones, the stage is set for Artemis I to kick off NASA's return to the Moon on schedule.
