Green Run Update: Start of Avionics Power Up for Hot Fire Test

The countdown is underway for the hot fire test with the core stage of NASA’s Space Launch System (SLS) rocket, scheduled for Jan. 16. Engineers have initiated power up of the avionics for the Artemis I core stage.

On Saturday, Jan.16, the management team will provide approval to proceed into the test, followed by a briefing for the test team in the Test Control Center at the B test complex.

Six barges filled with liquid hydrogen and oxygen will supply the propellant to the B-2 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, where the Green Run tests are taking place. The engines use cryogenic, or supercooled, liquid hydrogen as fuel and liquid oxygen as oxidizer to create combustion.

To fill each of the six barges, three for liquid oxygen and three for liquid hydrogen, it required 18 to 20 tanker trucks worth of propellant. The barges are towed by tug from a fuel depot at Stennis to the B-2 stand.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

In this video, SLS Stages Manager Julie Bassler, describes avionics and flight software testing conducted in the Systems Integration Laboratory at NASA’s Marshall Space Flight Center in Huntsville, Alabama, to support Green Run.

SLS Team Completes Propellant Loading of Core Stage During Green Run Test

NASA and Boeing engineers successfully completed propellant loading during the seventh core stage Green Run test, wet dress rehearsal Sunday, Dec. 20. The massive Space Launch System (SLS) rocket’s tanks were loaded with more than 700,000 gallons of liquid hydrogen and liquid oxygen.

Engineers working in the Test Control Center monitored all core stage systems during the test as propellant flowed from six barges into the core stage in the B-2 Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. First looks at the data indicate the stage performed well during the propellant loading and replenish process. Part of the test was to simulate the countdown with the tanks loaded, leading up to 33 seconds prior to the engines firing. However, the test ended a few minutes short of the planned countdown duration.

The core stage and the B-2 test stand are in excellent condition, and it does not appear to be an issue with the hardware. The team is evaluating data to pinpoint the exact cause of the early shutdown. Then they will decide if they are ready to move forward with the final test, a hot fire when all four engines will be fired simultaneously.

For more updates, visit this blog or the Green Run web site: https://www.nasa.gov/artemisprogram/greenrun

NASA ‘Go’ for Green Run Wet Dress Rehearsal

In a test readiness review on Friday, Dec. 4, NASA gave the “go” to start the next Green Run test, wet dress rehearsal, for NASA’s Artemis I Space Launch System (SLS) rocket core stage. The wet dress rehearsal is the first time the stage will be fully loaded with propellants and is planned to last approximately 48 hours. The test will begin on Saturday, Dec. 5 by powering up the core stage avionics, and engineers plan to load more than 700,000 gallons of cryogenic, or supercooled, propellant on Monday, Dec. 7.

This is the seventh of eight Green Run tests for the Artemis I core stage built by Boeing and the four RS-25 engines manufactured by Aerojet Rocketdyne. For this test, the team will focus on the core stage’s first exposure to cryogenic propellants. Six barges filled with liquid hydrogen and oxygen are supplying the propellant to the B-2 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi where the Green Run tests are taking place.

Engineers will monitor the core stage’s giant propellant tanks and complex propulsion systems for potential leaks or other issues that stages have historically experienced the first time cryogenic propellants are loaded. To prepare for Artemis launches, engineers also will put the stage through scenarios it might experience on the pad before lift-off. They plan to conduct two different holds in the countdown timeline while the stage is in a launch-ready state. This provides an opportunity to observe how the stage would respond if the countdown was paused during the upcoming hot fire test or a future Artemis launch. At the end of the test, all the propellant will be drained following similar procedures that would be used during a launch scrub on the pad. After draining the tanks, the team will review the test data before proceeding with plans for the hot fire test.

Check back at this blog for progress on the SLS core stage wet dress rehearsal. Learn more about Green Run here.