NASA repeated another test fire of the Space Launch System rocket in Mississippi Thursday after a previous attempt did not last as long as planned but this time the test exceeded expectations.
The eight-minute hot fire, known as the “green run” test of the SLS core stage is the last step before the hardware can be sent down to Kennedy Space Center to launch the Orion spacecraft on the first flight known as the Artemis-1 mission.
The SLS core stage booster, built by Boeing, contains the liquid hydrogen tank and liquid oxygen tank, along with four RS-25 engines as well as the computers that serve as the “brains” of the rocket.
At 4:37 p.m. the core stage fired its four engines on the test stand at NASA’s Stennis Space Center in Mississippi. The engines rumbled creating steam and massive amounts of smoke around the test stand before a safe engine shutdown 8 minutes and 15 seconds later.
A previous green run hot fire on Jan. 16 was also supposed to run for eight minutes but barely fired for one minute. The hydraulic system for one engine exceeded safety parameters, NASA officials said, and flight computers shut everything down 67 seconds into the ignition.
🚀 Today, the @NASA_SLS core stage that will power our @NASAArtemis I mission to the Moon successfully completed its Green Run hot fire test. If data looks good, its next stop is @NASAKennedy to be assembled with the other rocket elements. Here’s a recap: https://t.co/QpYSIQq4ox pic.twitter.com/aLmEkS9pbA— NASA (@NASA) March 18, 2021
Engineers had to repeat the test to get more data. NASA had said prior to the test it was hoping for at least four minutes.
By 2:30 p.m. engineers completed fueling the liquid hydrogen tank with 537,000 gallons and the liquid oxygen tank with 196,000 gallons, according to NASA.
After tanking was complete, the team chilled down the liquid oxygen propellant to condition it before the hot fire. The tanks can be loaded up to 22 times for testing and launches.
During the test, all four engines fired at the same time, just like what will happen when it launches from Florida. The engines should produce 1.6 million pounds of thrust for about eight minutes, providing NASA and Boeing enough data to determine if it’s ready to launch.
“Engineers collect data on how the stage behaved during critical operations, such as throttling the engines up and down and moving the engines dynamically in a variety of patterns,” according to a NASA update after the test.
The core stage will be refurbished before it’s sent via barge ship down to Florida.
“In coming days, engineers will scrutinize the data and determine if the stage is ready to be delivered to NASA’s Kennedy Space Center in Florida where it will be integrated with the twin solid rocket boosters already stacked in the Vehicle Assembly Building,” according to NASA.
The SLS rocket is slated to launch an uncrewed Orion spacecraft on a test flight around the moon in late 2021 or early 2022.
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