SLS Green Run – Take Two

Photo credit: NASA

March 18th, 2021 from the Stennis Space Center

Today NASA plans to revisit the Green Run test of the SLS core stage currently located at the Stennis Space Center in South Mississippi. Their initial Green Run test on January 16th of this year was stopped just sixty-seven seconds into the scheduled eight minute test. One of the hydraulic systems in an engine hit “intentionally conservative” limits in it’s flight software. NASA then announced February 25th would be the next testing date, but that was cancelled days ahead of time because of a “prevalve” problem in the core stage that supplies liquid oxygen to the engines. During this eight minute test all four RS-25 engines will be fired up, hopefully for the duration of the allotted time. Officials have stated that they need just four of those eight minutes to gather all the information they will need from the test.

Then assuming everything went well NASA should be able to announce the date of the first SLS launch. As of now they have been planning to launch the initial SLS mission in November of 2020, but these set backs may make that a hard schedule to keep. ” I think in a few weeks we’ll know if November is possible or if we need to push it out maybe a month or two” Steve Jurczyk (Acting NASA administrator) said yesterday in an interview. He also said that the margin NASA had in its schedule for a November launch had largely been used up because of delays caused by the pandemic and a series of tropical weather systems that passed near Stennis last summer and fall, along with technical issues during previous tests.

Top of the SRBs inside the VAB at Kennedy Space Center. Photo credit: NASA

Progress has continued to move forward at the Kennedy Space Center in Florida, where the SRBs (Solid Rocket Boosters) have completed their stacking on the mobile transport, and other advancements are being done in order to optimize the work flow, and compress the schedule once the core stage arrives in Florida. Last month we saw the Orion Crew Capsule for the last time before we see it atop the SLS rocket when it was rolled out of the Neil Armstrong Operations and Checkout building and sent over to the Multi-Payload Processing Facility where it will be loaded with fuel, and propellant for it’s journey around our Moon.

At 4:30 PM Est we saw the four engines previously used in the Shuttle Program fire up and run for the full eight minutes. After about eight minutes and twenty seconds the SLS core booster was shut down as applause rang from around the control room and viewers at home across the country. During the test some flames were seen around the base of the core stage. Bill Wrobel, NASA’s Green Run Manager said they were likely from some of the cork insulation, and wasn’t serious enough to cause an early termination of the run.