NASA rolls giant SLS rocket to launchpad for second Artemis moon mission

NASA rolled its massive Space Launch System rocket to its launchpad in Florida on Saturday, kicking off a final phase of preparations for the agency's Artemis II mission that is poised to send four astronauts around the moon and back as soon as next month.

Traveling just 1.6 km/h on its mobile launch platform, the 98 metre SLS emerged at sunrise from the giant garage doors of NASA's Vehicle Assembly Building at the Kennedy Space Center for a crawl to its launchpad some 6.4 kilometres away, as hundreds of agency employees and contractors staked out the sidelines to watch.

"We truly look at that and see teamwork, we see global cooperation, we see a strong nation leading the way," Artemis II mission commander Reid Wiseman told reporters on Saturday against the backdrop of the SLS cruising toward the launchpad.

"It represents an extraordinary American workforce, right there," said Artemis II mission astronaut Jeremy Hansen of Canada.

The rocket's upcoming Artemis II mission is the second under NASA's multibillion-dollar Artemis moon program, following an uncrewed flight in 2022, and the first to carry astronauts, who will fly around the moon in a 10-day journey taking them to the farthest humans have ever ventured in space.

The mission's crew includes three US astronauts and a Canadian astronaut, and is planned to launch as soon as February 6, though whether that date holds will hinge on a key "wet dress" rehearsal four days prior that simulates the launch countdown to catch any snags or issues before flight.

"Wet dress is really the driver" of the launch schedule, Artemis launch director Charlie Blackwell-Thompson told reporters on Friday. "You're going to need a little bit of time to look at the data" from the rehearsal, she said.

Also weighing on the February timeline is the launch of Crew-12, a separate, routine astronaut mission to the International Space Station whose launch date was moved up due to the early return of Crew-11 because of an astronaut medical issue. Resources required for that mission could contribute to a decision to launch Artemis II on a later date.

Artemis II has three launch windows through April, timed carefully with orbital mechanics to allow for a complex path around the moon and back. The agency can launch February 6 to April 11, March 3 to March 11, or April 1 to April 6.