CAPE CANAVERAL, Fla. (WHNT) – NASA is ready to attempt another wet dress rehearsal for the Artemis I rocket with modified testing procedures after an issue with a helium check valve pushed the test back to Tuesday.

The check valve is located in the upper stage of the Space Launch System (SLS) and is not easily accessible from the launch pad, according to Dr. John Belvins the SLS chief engineer from Marshall Space Flight Center.

With the helium check valve not acting as expected, changes to the test were required to protect the flight hardware, which means during the test fuel will not be loaded into the Interim Cryogenic Propulsion Stage (ICPS) in the upper stage of the rocket. As part of the test, they will still cool down the upper stage to the temperature needed for cryogenic fuel, however.

Crews can more easily access the valve from inside the Vehicle Assembly Building, so the decision was made to wait and replace the valve after the wet dress rehearsal was finished.

Artemis Launch Director Charlie Blackwell-Thompson laid out the new goals of the test. Those objectives include loading liquid oxygen and liquid hydrogen into the core stage of the rocket, conducting a full launch county down, demonstrating the ability to recycle the countdown clock, and then draining the core stage tanks.

The launch controllers’ call to stations was scheduled for 4 p.m. to go over the adjusted test procedures for the two-day test that is scheduled to end sometime Thursday afternoon.

A launch window for the uncrewed Artemis I mission will be decided after the wet dress rehearsal is completed and the rocket rolled back to the Vehicle Assembly Building.