NASA’s Artemis II mission reached a critical milestone this week as teams conducted a wet dress rehearsal of the Space Launch System rocket and Orion spacecraft during an unusually intense blast of cold air surged across Florida, delivering record-breaking low temperatures to the Sunshine State.

"Teams monitored all systems throughout the overnight hours during cold temperatures and high winds at the agency’s Kennedy Space Center in Florida," NASA wrote Sunday before moving ahead with the countdown.

The wet dress rehearsal is a full countdown simulation that includes loading the rocket with supercooled liquid hydrogen and liquid oxygen, running the clock down to a simulated launch time and then safely draining the propellants. The process is designed to verify that launch systems, ground equipment and procedures are ready ahead of the first crewed Artemis mission around the moon.

A full moon is seen shining over NASA’s SLS (Space Launch System) and Orion spacecraft, atop the mobile launcher in the early hours of Feb. 1, 2026 at Launch Pad 39B at NASA’s Kennedy Space Center in Florida. (Image credit: NASA/Sam Lott)

Operations began on Saturday at 8:13 p.m. EST and progressed through key milestones, including chilldown of propellant lines and tanking operations. NASA officials said completing the rehearsal successfully is a major step toward clearing the rocket for launch, which is currently targeted for no earlier than Feb. 8.

While Florida is no stranger to winter cold fronts, this event has been anything but typical. Arctic air plunged deep into the peninsula, sending temperatures into the 20s and 30s across much of central and South Florida. Several locations reported record-setting lows, and some cities even observed snow flurries — a rare sight in the Sunshine State.

The cold snap has produced unusual impacts across Florida, including reports of cold-stunned iguanas falling from trees as the reptiles temporarily lost mobility in the chilly conditions. Residents were urged to take precautions as hard freezes threatened sensitive vegetation, pets and exposed plumbing.

At Kennedy Space Center, weather is always a key factor in launch preparations, and the cold added an extra layer of complexity to the rehearsal. The space agency delayed beginning the test by 24 hours because of the cold.

Before moving forward with the countdown, NASA teams closely monitored temperatures, tank pressures and environmental control systems, using heaters and protective measures to safeguard critical spacecraft components from the chill.

NASA's Artemis II crew Jeremy Hansen (L), Christina Koch, Victor Glover (2nd-R) and Reid Wiseman respond to questions from the media as NASA's Space Launch System rocket is transported from the Vehicle Assembly Building to Launch Complex 39B at the Kennedy Space Center, Fla. on January 17. (Photo Credit: Joe Marino/UPI)

Despite the cold, NASA teams made steady progress through the rehearsal timeline on Monday. The test culminates Monday at 9 p.m. during the simulated launch window, but test operations will continue into the early hours on Tuesday.

Three NASA astronauts and one Canadian astronaut will launch on the Artemis II mission designed to orbit the moon and test the launch system before NASA aims to return astronauts to the lunar surface next year. Ahead of the launch, the Artemis II crew remain in quarantine at NASA's Johnson Space Center in Houston.