From: Marshall Space Flight Center
Posted: Friday, May 22, 2020
NASA is resuming work on a series of tests to bring the Space Launch System (SLS) rocket core stage to life for the first time, allowing engineers to evaluate the new complex stage that will launch the Artemis I lunar mission.
In January, engineers began activating the stage’s components one by one over several months through a series of initial tests and functional checks designed to identify any issues. Those tests and checks collectively called Green Run will culminate in a test fire replicating the stage’s first flight.
“Green Run is the step-by-step testing and analysis of the new SLS rocket core stage that will send astronauts to the Moon," said Richard Sheppard, the SLS Stages Green Run Test Lead from NASA’s Marshall Space Flight Center in Huntsville, Alabama. “This testing will reduce risks for, not only the first flight, but also for the Artemis mission that will land astronauts on the Moon in 2024.”
The Green Run test series, conducted in the historic B-2 Test Stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi, is a collaborative effort between the SLS program, the Stennis test team, core stage manufacturer Boeing and engine manufacturer Aerojet Rocketdyne. On March 18, work was temporarily suspended on Green Run when Stennis Space Center went to Stage 4 on the Agency Response Framework in response to a rise in COVID-19 cases in the area near Stennis.
Prior to pausing test operations, engineers completed the modal test, the first of the eight tests in the Green Run series, to understand the vibration characteristics of the core stage. Now, work is slowly and methodically starting back, as workers return to prepare the facility and resume testing.
“The team connected the facility with the rocket earlier this year, both electrically and mechanically,” said Ryan McKibben, Green Run test conductor at Stennis. “We are now preparing for the second test, which will power on the vehicle’s avionics and the three computers that control the rocket’s flight as it soars into space.”
The avionics are distributed throughout the stage. Engineers at Marshall designed software similar to the flight software for Green Run. A special stage controller will be used to simulate the Launch Control Center operations that will control the actual launch at Kennedy Space Center in Florida.
“The core stage avionics along with Green Run software have successfully completed tests in our test laboratories at Marshall, said Lisa Espy, the core stage avionics lead at Marshall. “I am excited to see the flight systems come to life that will control the rocket as it sends the first Artemis mission to the Moon.”
Green Run tests minimize risk to the core stage and ensure the stage satisfies design objectives and validates design models:
After the hot fire test, engineers will refurbish the core stage and configure it for its journey to Kennedy for launch preparations. The next time the RS-25 engines fire, the SLS will launch in an epic debut of Artemis I -- the first in a series of increasingly complex missions that will enable human exploration to the Moon and Mars.
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