Green Run Update: NASA Targets March 18 for SLS Hot Fire Test

NASA is targeting Thursday, March 18 for the second hot fire of the Space Launch System (SLS) rocket’s core stage at NASA’s Stennis Space Center near Bay St. Louis, Mississippi.

After performing tests to demonstrate that a recently repaired liquid oxygen pre-valve was working, the team has continued to prepare the core stage, its four RS-25 engines, and the B-2 test stand for the second hot fire at Stennis. Later this week, the team will power up the core stage again and do a final check of all its systems. Then, on March 16, two days before the test, they will power up the stage, starting the clock for the second hot fire.

Test Like you Fly Infographic
This infographic explains the objectives of the Space Launch System rocket’s core stage Green Run test series.

This hot fire is the last test before the Artemis I core stage is shipped to the agency’s Kennedy Space Center for assembly and integration with the rest of the rocket’s major elements and the Orion spacecraft. Exploration Ground Systems teams at Kennedy have stacked all parts of the solid rocket boosters for Artemis I in the Vehicle Assembly Building and are finishing up booster assembly. After the core stage arrives, it will be lifted and placed between the two boosters and attached at the core stage engine and intertank sections. Other parts of the rocket and the Orion spacecraft are also at Kennedy and are being prepared for final assembly and integration.

NASA’s SLS rocket is the most powerful rocket in the world, built to send both astronauts aboard Orion and supplies on missions to the Moon and beyond. The Green Run is a comprehensive test of the SLS core stage, a complex new rocket stage that not only includes four RS-25 engines and enormous propellant tanks that hold more than 700,000 gallons of super cold propellant, but also flight computers and avionics that control the first eight minutes of flight. The Green Run test series will help validate that the SLS core stage is ready for its first flight on Artemis I and subsequent missions.

Check back at this blog for an update on core stage power up for the second Green Run hot fire. For more information about SLS Green Run, visit