Green Run Update: Tanking Complete for Rocket Hot Fire Test

Engineers have completed tanking for the hot fire test of NASA’s Space Launch System (SLS) rocket core stage at the agency’s Stennis Space Center, and the countdown is proceeding normally.

The liquid hydrogen tank holds 537,000 gallons of liquid hydrogen, cooled to minus 423 degrees Fahrenheit. The liquid oxygen tank holds 196,000 gallons of liquid oxygen, cooled to minus 297 degrees Fahrenheit. After tanking is complete, the team will continue chilling down the liquid oxygen propellant to condition it before the hot fire. While they are conditioning the liquid oxygen, they replenish the liquid hydrogen as it boils off due to temperature fluctuations as the propellant is loaded. The tanks can be loaded up to 22 times for testing and launches.

core stage liquid hydrogen tank
This image shows the core stage liquid hydrogen tank at NASA’s Michoud Assembly Facility in New Orleans where it and the rest of the core stage where built and assembled. The flight core stage for the Artemis I mission is being tested today. Boeing, the prime contractor for the core stage, has already manufactured liquid hydrogen tanks for the Artemis II and Artemis III lunar missions.

This part of the test timeline is also important as it pertains to simulating launch. During a launch, many activities will be happening on the pad at this time, such as loading the crew. The hot fire test provides an opportunity to demonstrate that the core stage can remain in a stable configuration and be replenished as needed before engine firing to launch the rocket.

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