NASA's Moon Rocket Faces Engine Issue, Artemis I Countdown Put on Hold

Artemis I SLS and Orion on the pad 9 photos
Photo: NASA via Twitter
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Everyone is holding their breath for the launch of Artemis I, the first test flight of NASA's Space Launch System (SLS) rocket and Orion spacecraft. The mission was supposed to lift off on Monday (Aug 29) from Kennedy's Launch Pad 39 at 8:33 EDT, but the countdown clock was put on hold after the team ran into some issues with one of the SLS engines.
The day started off with a weather delay of approximately 45 minutes for the SLS' core stage fueling. Tanking operations officially began at 1:14 a.m. EDT. Everything went smoothly until the teams proceeded with liquid hydrogen fill. During the transition from slow fill to fast fill operations, they detected a leak.

The problem was quickly resolved, so they moved to the upper stage tanking. As the liquid oxygen was being loaded into the upper stage, NASA noticed a crack in the thermal protection system material on one of the core stage's flanges while loading liquid oxygen into the upper stage. However, it turned out to be a stress crack in the insulating foam rather than a structural one in the tank. So it managed to clear that out.

But the team has encountered another issue, which made them put the clock countdown on hold. They noticed that one of the engines was not bleeding properly. There are four RS-25 engines at the bottom of the core stage. All four bleed out liquid hydrogen and liquid oxygen when the launch team commands it.

Teams condition the engines by increasing pressure in the core stage tanks in order to bleed some cryogenic propellant into the engines and get them to the right temperature for liftoff. Engine no. 3 does not appear to be in sync with the other engines, so engineers are trying to raise the pressure in the bleed on engine no. 3.

NASA stopped the countdown at T-minus 40 minutes. Teams are currently discussing a troubleshooting plan. There are already several issues that NASA had to deal with ahead of the launch. Artemis I was initially scheduled to launch at 8:33 a.m. EDT from Launch Pad 39B at the Kennedy Space Center in Florida. The liftoff can be pushed back until 10:33 EDT, so hopefully, the agency will soon fix the engine problem. For more updates on the launch, check out our live coverage live text or watch NASA TV live streaming.

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About the author: Florina Spînu
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Florina taught herself how to drive in a Daewoo Tico (a rebadged Suzuki Alto kei car) but her first "real car" was a VW Golf. When she’s not writing about cars, drones or aircraft, Florina likes to read anything related to space exploration and take pictures in the middle of nature.
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