NASA's SLS rocket and Orion spacecraft stand on Complex 39B at the Kennedy Space Center in Florida at dawn on Friday. The launch is set for Monday. Photo by Joe Marino/UPI | License Photo
Aug. 23 (UPI) -- NASA says it's set to launch the first test flight Monday of its long-anticipated mission that will return U.S. astronauts to the moon for the first time in 50 years.
The Artemis 1 mission is scheduled for liftoff from Kennedy Space Center in Florida after 8:30 a.m. Monday within a two-hour window, the agency said in a briefing Monday.
The mission is the first test of the newly minted Space Launch System, which NASA touts as its most powerful megarocket ever.
"We are a go for launch, which is absolutely outstanding," NASA associate administrator Robert Cabana said. "This day has been a long time coming."
The unmanned Orion capsule, capable of holding four astronauts, will take about a week to get to the moon, where it will spend 42 days in orbit before making its way back to Earth on Oct. 10 if everything goes smoothly.
Mission managers said they planned to stretch the limits of the spacecraft to test its overall readiness for human flight and identify any issues.
The 42 days of the test flight dwarfs the standard 10 days an Artemis crew would actually spend in space.
Among the tests that will be conducted during the mission are mannequins fitted with sensors to measure the effects of space flight on the body. The capsule will also deploy miniature space exploration devices that look similar to Rubik's Cubes.
NASA officials said anything could go wrong during the test flight but expressed hope that the mission would overcome any unforeseen circumstances.
"This is the first flight of a new rocket and a new spacecraft," Artemis 1 mission manager Mike Sarafin said at Monday's briefing. "We're doing something that is incredibly difficult to do and does carry inherent risk in it."
The Artemis spacecraft is the first to be built solely by NASA since the Space Shuttle fleet took its final flight in 2011.
NASA plans to launch Artemis 2 with a crew by 2024, but the moon landing won't happen until the Artemis 3 mission in 2025.
That mission will feature a starship lander built by SpaceX, which will make carry astronauts on repeated trips to the moon's south pole.
A total of 24 astronauts have visited the moon, while only 12 have actually stepped foot on the lunar surface. The Apollo missions, which lasted from 1969 to 1972, were the final manned expeditions by the United States.
The Space Launch System (SLS) rocket carrying an Orion spacecraft lifts off on the maiden flight of NASA's Artemis Program from Complex 39-B at the Kennedy Space Center on November 16, 2022. Photo by Joe Marino/UPI | License Photo