The twohour launch window opens at 2:17 PM ET on September 3.
After clearing the launch Monday morning, the launch team spent the rest of the day evaluating data collected during the attempt. Mission directors shared an update Tuesday evening.
The Artemis I stack, which includes the Space Launch System rocket and the Orion spacecraft, remains at Launchpad 39B at the Kennedy Space Center in Florida.
One of the rocket’s four RS25 engines, identified as engine no. 3, failed to reach the proper temperature range required for the engine to start on takeoff.
The engines must be thermally conditioned before the supercooled propellant is passed through them prior to takeoff. To prevent the engines from experiencing any temperature shock, the launch controllers increase the pressure of the center stage’s liquid hydrogen reservoir to send some liquid hydrogen to the engines. This is known as “bleeding”.
Liquid hydrogen is about minus 423 degrees Fahrenheit (minus 252 degrees Celsius).
Mission directors suspected that the problem with engine no. 3 was actually a problem with the bleed system, rather than the actual engine.
Other problems included storms, a leak in an 8inch line used to fill and drain liquid hydrogen from the rocket’s core stage, and a hydrogen leak from a vent valve in the intertank of the central stage also caused delays on Monday morning that prevented takeoff during the two – Hour start window.
“” We agreed on what was called option 1, which was to operationally change the loading procedure and start engine cooling earlier. We also agreed to do some work on the bearing to address the leak we saw in the umbilical of the hydrogen tail service mask,” said Mike Sarafin, Artemis mission manager at NASA Headquarters.
The current forecast for Saturday includes a chance for showers and thunderstorms in the morning and early afternoon, so the launch team will be watching the forecast closely, said Marc Berger, the launch weather office with the 45th weather squadron of the US Space Force.
There is a 60 percent chance that a violation will time during the release window, Berger said.
There is still a backup opportunity for the Artemis I mission to launch on September 5 as well.
The Artemis I mission is just the beginning of a program that will aim to return humans to the Moon and eventually land manned missions to Mars.