NASA heads back to moon with Artemis I launch

Fifty years after the final Apollo moon mission, NASA has embarked on a crucial first step toward returning astronauts to the lunar surface.

The agency launched its new megarocket and space capsule on a mission to the moon Wednesday in an uncrewed test flight known as Artemis I. The huge rocket blasted off from NASA’s Kennedy Space Center in Cape Canaveral, Florida, at 1:48 a.m. ET.

"[F]or the Artemis generation, this is for you," launch director Charlie Blackwell-Thompson, the agency's first female launch director, said before she gave the go-ahead for liftoff.

The event was the long-awaited first liftoff of NASA’s Space Launch System, or SLS, a next-generation booster that the agency says is the “most powerful rocket in the world.” Atop the 322-foot-tall rocket was the gumdrop-shaped Orion capsule that will eventually carry astronauts to the moon.

Blackwell-Thompson told her team members in an address after the launch that their work will inspire future generations.

“You have earned this moment,” she said. “You have earned your place in history.”

The crucial liftoff represents the first step toward returning U.S. astronauts to the moon and eventually on to Mars, Blackwell-Thompson said.

“You are part of a first. They don’t come along very often — once in a career, maybe,” she said. “But we are all part of something incredibly special: the first launch of Artemis.”

The 26-day Artemis I flight is designed to test the SLS rocket and the Orion capsule before missions with humans onboard. The spacecraft is carrying a set of mannequins laden with sensors to study conditions during the flight and to measure radiation levels throughout the mission.

The Orion spacecraft will journey to the moon and remain in orbit for a few weeks before it returns to Earth. The capsule is expected to splash down in the Pacific Ocean on Dec. 11.

The Artemis I mission finally got off the ground after two attempts — one in late August and another in early September — were called off because of a faulty sensor and a series of hydrogen fuel leaks.

The flight was also thwarted by stormy weather. The rocket was rolled back to NASA’s Vehicle Assembly Building in late September ahead of Hurricane Ian, which caused catastrophic damage across southwestern Florida. Last week, the agency was again forced to reschedule the Artemis I launch as Hurricane Nicole slammed into Florida’s east coast on Nov. 10, making landfall more than 70 miles south of the launch pad, according to NASA.

This time, the huge SLS booster did manage to rocket into orbit, although the countdown to liftoff was not without its own drama.

Shortly before 10 p.m. ET, intermittent leaks of liquid hydrogen were detected from a valve at the base of the launch pad. The leaks were different from the ones that forced NASA to call off the first two Artemis launch attempts.

The agency opted to send a highly trained "red team" of two technicians out to the launch pad to torque down bolts on the valve. The work occurred close to the mostly fueled rocket, within what's known as the blast danger area, and was thus closely monitored by safety teams, agency officials said.

Despite running around 40 minutes behind schedule, engineers were able to fix the leak and proceed with the rest of the fueling process and the countdown.

Artemis is named for the goddess of Greek mythology who was the twin sister of Apollo. If this and subsequent test flights are successful, the agency could send humans to the lunar surface as early as 2025.

As part of the Artemis program, NASA envisions regular missions to establish a base camp on the lunar surface before it eventually ventures to Mars.

The much-anticipated Artemis I test flight launched after more than a decade of work by NASA to develop a megarocket that surpasses the capabilities and size of the iconic Saturn V rockets used during its Apollo moon program, which had its last flight in 1972. The initiative has been criticized over the years for being years behind schedule and billions of dollars over budget.

At a House Science, Space and Technology Committee hearing this year, NASA Inspector General Paul Martin said the agency will likely have spent $93 billion on the Artemis program from 2012 to 2025. He said each Artemis launch is expected to cost around $4.1 billion.

If it succeeds, Artemis I will be followed by a planned Artemis II test flight, tentatively scheduled sometime in 2024. That mission will launch four astronauts in the Orion spacecraft on an expedition around the moon. After that, NASA said, the Artemis III flight will include the first woman and the first person of color to land on the moon.

This article was originally published on NBCNews.com