NASA’s hoped-for debut mission in a multiphase program aiming to return astronauts to the moon for the first time in 50 years will have to wait as the scheduled launch of the agency’s new mega-rocket was scrubbed Monday morning due to technical issues.

Even without the glitches, NASA officials noted inclement weather around the Kennedy Space Center in central Florida would likely have led to a launch reschedule.

But NASA leaders were somewhat optimistic that the problems could be resolved in time for another attempt when the next launch window opens around midday on Friday.

At a follow-up press conference Monday, NASA said the Artemis I mission was canceled after compounding issues arose during a process to prep the engines on the new, massive Space Launch System.

NASA Administrator Bill Nelson noted flight engineers successfully navigated several technical challenges in pre-launch preparations early Monday morning but ran up against a problem that required additional time to address and the launch was scrubbed at 8:34 a.m. EDT.

“I am very proud of this launch team,” Nelson said. “They have solved several problems along the way and they got to one that needed time to be solved. This is a brand-new rocket (and) it’s not going to fly until it’s ready.

“There are millions  of components of this rocket and its systems and, needless to say, its complexity is daunting when you bring it all into the focus of a countdown.”

Nelson said that scrubbed launch attempts are a normal part of the massive coordination and preparation that are part of every space mission.

“When you’re dealing with a high-risk business, and space flight is risky, that’s what you do,” Nelson said. “You buy down that risk. And of course, that is the whole reason for this test flight ... to stress it and to test it to make sure it’s as safe as possible.”

NASA’s Artemis mission manager Mike Sarafin said lightning strikes on Saturday near the launch pad, a software issue related to the Orion crew capsule and a hydrogen leak detected during the fueling process were all problems encountered, and resolved, ahead of Monday’s launch window.

But a critical step that requires cooling down the four SLS rocket engines before fuel is fed to them for ignition was interrupted when one of the engines did not cool sufficiently. And that issue was exacerbated, Sarafin said, by the discovery of a faulty ventilation valve.

“The combination of not being able to get engine three chilled down, and the vent valve issue ... really caused us to pause today and we felt like we needed a little more time,” Sarafin said.

He also noted unsettled weather in the launch area would have likely led to the same decision had technical problems not been a factor.

“There was also a series of weather issues throughout the (launch) window,” Sarafin said. “We would have been no-go for weather at the beginning of the window due to precipitation and, later on in the window, we would have been no-go for lightning within the launch pad area.”

Sarafin said the Artemis launch team is scheduled to reconvene on Tuesday to assess and attempt to resolve the technical issues encountered Monday morning. He also noted that a Friday launch attempt was still “definitely in play” and that NASA would provide a status update on the Artemis I mission Tuesday evening.

The crewless Artemis I mission is scheduled to run for 42 days on a flight that will allow NASA experts to test the new SLS components, many of which have been repurposed from the old space shuttle program and other systems, as well as the Orion space capsule.

That capsule, the eventual home for future space travelers, will be carried into lunar orbit where it will take a spin around the moon and then head back to earth for a fiery plunge through the atmosphere at some 25,000 mph before splashing down in the Pacific Ocean at the end of the mission.

Artemis I is just the first in a three-phase program aiming to put astronauts back on the surface of the moon for the first time since the final Apollo moon visit in December 1972.

Artemis II, currently anticipated for sometime in 2024, will head to space with a four-person crew in the Orion capsule that will fly the craft around the moon in further testing. Then, if all goes according to NASA’s current plan, the SLS/Orion package will return on a mission that will include a landing on the moon’s surface in 2025. Along the way, NASA wants to put a small space station, the Lunar Gateway, in orbit around the moon and has future plans that include a moon base station, the Artemis Base Camp.

So, why go back to the moon?

In a posting on the Artemis missions’ website, NASA lists a few reasons why it’s devoting billions of dollars to making moon landings, once again, a priority.

“We’re going back to the moon for scientific discovery, economic benefits and inspiration for a new generation of explorers: the Artemis Generation,” NASA says. “While maintaining American leadership in exploration, we will build a global alliance and explore deep space for the benefit of all.”

And while a return to the moon smacks a little of “been there, done that,” NASA says it’s committed to accomplishing some other first benchmarks as part of the series of Artemis missions, including extending manned exploration deeper into the solar system.

“With Artemis missions, NASA will land the first woman and first person of color on the moon, using innovative technologies to explore more of the lunar surface than ever before,” NASA says in a web posting. “We will collaborate with commercial and international partners and establish the first long-term presence on the moon. Then, we will use what we learn on and around the moon to take the next giant leap: sending the first astronauts to Mars.”

NASA says its SLS launch system stands at 322 feet high — taller than the Statue of Liberty — and weighs 5.75 million pounds when loaded with fuel. During launch and ascent, the SLS will produce 8.8 million pounds of maximum thrust, 15% more thrust than the Saturn V rockets that propelled Apollo astronauts to the moon.