The countdown clock began to appear on Saturday for the first launch of NASA’s new Space Launch System rocket on Monday A long-awaited mission To send an unmanned Orion crew capsule around the moon and back.

Charlie Blackwell Thompson, NASA’s first launch director, called her team to their stations in firing room 1 at the Kennedy Space Center and began a carefully written 46-hour, 10-minute countdown at 10:23 a.m. EDT.

“At the moment we are not dealing with any significant issues,” she told reporters at a press conference before the flight. “So I’m happy to report that and everything is going on schedule.”

Shortly after the briefing, lightning struck two of the three 600-foot protective turrets around the SLS rocket at Launch Pad 39B. The strike prompted a review of data to ensure that no sensitive electrical systems were affected, but initial checks indicated the strikes were “low-volume”.

If all goes well, engineers working through a remote-controlled plan to begin pumping 750,000 gallons of liquid oxygen and hydrogen fuel into the SLS giant rocket’s primary stage at 12:18 a.m. EDT, clearing the way for a liftoff at 8 :33 a.m. Opening for two hours. Forecasters expect there to be a 70 percent chance of good weather.

The 42-day unmanned test flight of the SLS rocket and the $4.1 billion Orion crew capsule is a milestone in NASA’s efforts to return astronauts to the lunar surface for long-term exploration and ultimately test equipment and procedures for several years. Trips to Mars.

“With the launch of Artemis 1 on Monday, NASA is at a historic inflection point, preparing to begin the most important series of scientific and human exploration missions in more than a generation,” said Bhavya Lal, NASA associate director for technology, policy and strategy.

“We are making sure that the agency’s architecture for human exploration is grounded in a long-term strategic vision, which is the continued American presence on the Moon, Mars, and throughout the Solar System.”

But Mission Director Mike Sarafin cautioned, “This is a test flight. We keep in mind that this is a meaningful stress test of the Orion spacecraft and the Space Launch System rocket. It’s a new innovation, it’s a new rocket and a new spacecraft to send humans to the Moon on the next flight.”

“This is something that hasn’t been done in over 50 years and it is very challenging. We will learn a lot from the Artemis 1 test journey… We understand there is a lot of excitement about this, but the team is very excited. Focused.”

One question that goes into the countdown is the case of a 4-inch liquid hydrogen quick-disconnect installation that leaked during a countdown practice and refueling test on June 20.

The installation was fixed after the rocket was returned to the NASA Assembly Building. But hydrogen leaks don’t usually show up unless the equipment is exposed to extremely cold temperatures — in this case, minus 423 degrees Fahrenheit — and won’t happen until refueling on Monday morning.

If a leak that violates safety standards is detected, the release will be deleted. But Blackwell Thompson said she was confident the installation would work normally.

“You don’t really get the full test until you’ve done it in very cold conditions,” she said in an interview. “So we think we’ve done everything to correct this issue, and for sure on launch day, as part of our loadout, we’ll know for sure.”

The primary goals of the Artemis 1 mission are to verify the performance of the giant SLS rocket, put the Orion crew capsule in its stride and return it safely to Earth, and ensure that the capsule’s 16.5-foot-wide heat shield can protect the returning astronauts. From high-speed heat to return.

An instrumented and space-equipped mannequin, “Moonikin Campos,” and two artificial female torsos will help scientists measure the radioactive environment of deep space, along with vibrations, sound levels, acceleration, temperatures and pressures in the crew cabin throughout the mission.

If the flight goes well, NASA will proceed with its plans to launch four real astronauts on a frequent path to return freely around the moon in late 2024, followed by a mission to land two astronauts near the lunar south pole early in 2025.

That flight will rely in large part on ongoing funding from Congress, the development of new spacesuits to walk on the surface of the Moon, and SpaceX’s progress in developing a lunar lander based on the design of the future spacecraft rocket, which has not yet flown into space.

NASA administrators say they are optimistic, but it is not yet known how realistic the 2025 landing goal will be.

“We’re working on that pace as well,” said astronaut Randy Bresnik, who added that SpaceX is “working on that pace as well.”

“And that gives great hope that if we’re going to get there, we’ve got the right partner for that first mission,” Bresnik said. “Suits and Starship, the lunar lander, go hand in hand. We can’t have one without the other. So we’ll get more clarity in the next few months.”

William Harwood

Bill Harwood has covered the US space program full-time since 1984, first as Cape Canaveral bureau chief for United Press International and now as a consultant for CBS News. He has covered 129 Space Shuttle missions, every interplanetary flight since Voyager 2’s flyby of Neptune and dozens of commercial and military launches. Located at the Kennedy Space Center in Florida, Harwood is a devoted amateur astronomer and co-author of “Comm Check: The Final Flight of Shuttle Columbia.”