NASA’s first full-up, on-the-ground test for the main engines on its heavy-lift Space Launch System rocket ended prematurely today due to an automated shutdown.
“Today was an important day,” NASA Administrator Jim Bridenstine said after the test. “I know not everybody is feeling as happy as we otherwise could, because we wanted to get eight minutes of a hot fire, and we got over a minute.”
Despite the early shutdown, NASA said the “Green Run” engine test produced valuable data in preparation for the first honest-to-goodness SLS launch, currently set for late this year.
That launch would kick off an uncrewed round-the-moon trip for NASA’s Orion spacecraft. The mission, known as Artemis 1, is a key step in the plan to send astronauts around the moon on NASA’s Artemis 2 mission in the 2023 time frame, and then put them on the lunar surface by as early as 2024 during the Artemis 3 mission.
Today’s test at Stennis Space Center in Mississippi focused on the SLS rocket’s core stage and its four Aerojet Rocketdyne RS-25 engines. The engines are refurbished leftovers from the space shuttle program, and had been used on shuttle missions going as far back as 1998.
Each of the engines delivers more than 400,000 pounds of thrust, adding up to 1.6 million pounds of thrust when all four engines are firing. When the Artemis 1 mission lifts off, the SLS’ solid rocket boosters will bring total thrust to more than 8 million pounds. In comparison, the Saturn V moon rocket’s first stage delivered 7.6 million pounds of thrust back in the 1960s and 1970s.
NASA’s SLS team put months of work into the preparations for today’s test. More than 700,000 pounds of super-chilled hydrogen and oxygen were loaded into the core stage’s tanks for the engine firing. When the countdown reached zero, all four engines roared into life on cue, sending giant clouds of steam billowing into the air.