The agency announced today (Aug. 30) that the launch of Artemis 1 will now take place on Saturday (Sept. 3).
If everything goes as planned, Artemis 1 will launch from NASA's Kennedy Space Center (KSC) in Florida from Pad 39B.
The Artemis 1 mission is the first in NASA's Artemis programme, which aims to establish a long-term human presence on and around the moon.
It's also the first flight of NASA's massive new Space Launch System (SLS) rocket, which will carry an uncrewed Orion capsule to and from lunar orbit.
Members of the Artemis 1 team noticed that one of the four RS-25 engines powering the SLS core stage was not cooling to the desired low temperature.
Replacing the sensor would almost certainly necessitate moving the Artemis 1 stack away from Pad 39B and back to KSC's massive Vehicle Assembly Building.
The team intends to make a few changes to the countdown plan, beginning the engine cooling process 30 to 45 minutes earlier than previously.