NASA has moved forward with a critical prelaunch test for its Artemis II mission as an unusual wave of cold weather bears down on Central Florida, prompting officials to adjust operations at Kennedy Space Center in Cape Canaveral.

The space agency confirmed that the Artemis II “wet dress rehearsal” will now take place on Saturday, earlier than originally planned, to avoid sub-freezing temperatures expected late Sunday into Monday. Forecasters warn that the region could experience some of the coldest conditions seen in years, raising concerns about equipment performance and safety protocols.

The wet dress rehearsal is a full-scale simulation of launch procedures. During the test, the Space Launch System rocket will be fully fueled, and engineers will conduct a countdown sequence stopping just seconds before liftoff. The exercise allows teams to verify systems, evaluate fueling operations, and confirm emergency response procedures at Launch Pad 39B.

NASA officials said the rehearsal is a required milestone before the Artemis II mission can be cleared for launch. Engineers will also collect data on vehicle performance and conduct emergency escape system checks at the pad. The countdown is expected to begin in the evening and could extend into the early morning hours if additional testing is needed.

Cold temperatures have added pressure to preparations, with technicians taking steps to shield sensitive components from exposure. Environmental control systems are being monitored closely to maintain proper temperature levels inside the Orion spacecraft and across ground support equipment.

Alongside weather concerns, NASA continues to address technical issues identified during earlier testing. Adjustments were recently made to the launch pad’s emergency evacuation baskets after they failed to reach their intended stopping point during drills. Additional testing is also underway on Orion’s potable water system following elevated readings in earlier samples.

Meanwhile, the Artemis II crew remains in preflight quarantine in Houston as part of standard health protocols ahead of the mission. Artemis II is slated to be the first crewed flight of NASA’s lunar program in decades, carrying astronauts on a mission around the Moon. The launch window currently opens no earlier than February 6, though officials caution that timelines remain dependent on test results and weather conditions.

NASA said it will continue monitoring the cold front and evaluate whether further adjustments are needed in the coming day