NASA's lunar spacecraft is sealed up for launch.
"The crew module hatch was closed at approximately 3:30 a.m. Thursday," NASA stated in a blog post (opens in new tab) describing some of the last steps before liftoff from the agency's Kennedy Space Center in Florida.
"Meteorologists with the U.S. Space Force Space Launch Delta 45 currently predict a 70% chance of favorable weather conditions for launch on Aug. 29," the agency added. Periodic rain showers remain the primary concern for launching on time at 8:33 a.m. EDT (1233 GMT), although the launch window does extend for two hours.
Artemis 1 is the debut installment of the Artemis program, which aims to put astronauts around the moon in 2024 with Artemis 2 and upon the lunar surface in 2025 with Artemis 3. NASA is framing the program as an opportunity to test out technology, procedures and hardware ahead of bringing humans to Mars.
The uncrewed Artemis 1 will loop around the moon for an approximately 40-day mission to test the system's endurance against radiation, space weather, cold and other factors of the space environment ahead of certifying it for humans.
The two-day countdown for Artemis 1 will begin on Sunday (Aug. 28) as the SLS rocket targets its first-ever launch. The booster, which is the most powerful NASA has yet built, has gone through numerous ground tests including a near 50-hour-long "wet dress rehearsal" fueling testing in June.
U.S. Vice President Kamala Harris will be among the attendees at the launch on Monday, her office confirmed in an exclusive to Space.com published Friday (Aug. 26). Harris will tour KSC and deliver a speech concerning NASA space leadership.