After moving the massive SLS rocket and Orion spacecraft to the launchpad last weekend, NASA is now eyeing the next stage of its preparations for Artemis II, the first crewed lunar mission in more than five decades.
Now firmly in place at Launch Pad 39B at the Kennedy Space Center in Florida, the rocket will be put through a so-called “wet dress rehearsal” this weekend.
A wet dress rehearsal is the final full-scale test before a rocket launch, where the vehicle is loaded with cryogenic propellants such as liquid oxygen and hydrogen, and the countdown proceeds to just a few seconds before ignition.
The important procedure simulates real launch conditions to verify that all systems, ground equipment, and team procedures are functioning correctly under operational stress.
Any issues that surface can then be quickly addressed ahead of the launch, ensuring the mission’s safety and success.
“Technicians hooked up purge lines meant to keep cavities of the rocket and spacecraft in the right conditions, enabled communications with the Launch Control Center, and performed swing tests of the crew access arm — the bridge that allows the crew and other personnel to access Orion,” NASA said in a post on its website.
“The emergency egress system, a slide-wire and basket systems that allows for a quick exit in the case of an emergency, also was connected, allowing teams to practice releasing the baskets. Orion and elements of the rocket, including the core stage, interim cryogenic propulsion stage, and boosters, have been powered on.”
The team is now preparing to load around 700,000 gallons of cryogenic propellants into the rocket. Following the countdown, the propellants will be removed from the SLS rocket.
NASA said that if any serious anomalies are found during the wet dress rehearsal, engineers can transport the SLS and Orion back to the nearby Vehicle Assembly Building for additional work.
Three NASA astronauts and one from the Canadian Space Agency will embark on a 10-day mission around the moon — with no touchdown on the lunar surface — in a flight that will pave the way for a future lunar landing, possibly before the end of this decade.
The launch window opens on February 6.
“The mission management team will assess flight readiness after the wet dress rehearsal across the spacecraft, launch infrastructure, and the crew and operations teams before selecting a launch date,” NASA said.

