ORLANDO, Fla. — All signs were pointing to optimism for NASA’s second shot at a moonshot on Saturday, but a familiar foe forced another scrub for the Artemis I flight from Kennedy Space Center. Now the rocket may be forced to head back to the Vehicle Assembly Building with its next launch opportunity uncertain.
“We will not be launching in this launch period,” said NASA’s Jim Free, associate administrator for the Exploration Systems Development Mission Directorate, noting no attempt would be possible this week. “It’s definitely off the table.”
A liquid hydrogen leak detected during NASA’s attempts to load the Space Launch System rocket’s core stage with the required 733,000 gallons of cryogenic propellants had engineers scrambling to find a fix.
As the morning progressed toward the opening of an afternoon launch window, though, NASA’s three attempts to remedy the leak fell short, eventually leading to the launch director pulling the plug at 11:17 a.m.
Free said proposed repairs will take weeks, and that a safety agreement with the U.S. Space Force would require a rollback unless a waiver could be granted.
“This is part of our space program. Be ready for the scrubs,” said NASA Administrator Bill Nelson.
When Nelson flew on Space Shuttle Columbia in 1986 as a member of the U.S. House of Representatives, his mission was scrubbed four times. Two previous shuttle flights each had six scrubs before successful launches on try No. 7.
“So this is part of the space business,” he said.
Echoing comments from Monday’s scrub stating “we will go when it’s ready,” Nelson reiterated that Artemis I is a test, designed to prove the hardware can support human crew on future missions that aim to orbit the moon on Artemis II in 2024 and return humans, including the first woman, to the lunar surface on Artemis III as early as 2025.
Artemis’ next available launch window runs Sept. 19-Oct. 4, but that would put it up against the planned launch of a SpaceX Dragon for the Crew-5 mission to the International Space Station. After that, the windows are from Oct. 17-31, Nov. 12-27 and Dec. 9-23. Each window has only certain days during which the Earth and moon are in the right position for the mission.
Free said the teams would go through more data before making a target launch window decision, but he did say they won’t compete with the SpaceX launch attempt that could be as early as Oct. 3.
“We need to make sure we de-conflict with them, so that will weigh into what we do,” Free said.
When it does lift off, the SLS would become the most powerful rocket to ever launch from Earth. It will generate 8.8 million pounds of thrust to send the Orion spacecraft on a multiweek mission to orbit the moon and head back to Earth at 24,500 mph, the fastest ever for a human-rated spacecraft that will endure temperatures near 5,000 degrees Fahrenheit on reentry.
Nelson praised the launch team for making sure this test flight paves the way for future human missions.
“They do it right. They do it by the book. They do it very professionally,” he said. “These are human being lives on the top of that rocket and I can tell you when you strap into that rocket, you are very grateful that you’ve got a launch team like this, that knows what they’re doing and they’re not going to let you go until it’s time.”
Saturday’s attempt looked more likely following the mission management team’s run-through of data from issues that rose up during Monday’s scrub. Brevard County officials predicted up to 400,000 people might make their way to the Space Coast to check out the launch.
But the super-cooled liquid hydrogen continued to be thorn in NASA’s side, as leaks in various lines had also stymied NASA’s wet dress rehearsals in April and June, and had even delayed part of Monday’s launch attempt.
This one was much larger than the one seen on Monday, though.
Artemis mission manager Mike Sarafin said teams are debating doing repairs at the launch pad. But even if they can fix the issues there, current agreements with the Space Force’s Space Launch Delta 45 — which that manages the Eastern Range for launches – will not let Artemis stay at the pad longer than 25 days without checking the batteries for its flight termination system, which is needed in an emergency during launch. That has to be done at the VAB.
“It is not our decision. It is the Range’s decision,” Sarafin said, “They’re the ones responsible for managing public safety.”
That said, there could be a waiver granted to extend Artemis I’s stay on launch pad 39-B, but there are other limits on how long Artemis remain there that could come into play.
Teams want to replace the parts on the feed line that was the source of the leak, and then test it to make sure it will work on future attempts. Testing at cryogenic temperatures, though, cannot be done at the VAB — only at the launch pad.
“As part of this initial test flight, we’re learning the vehicle, we’re learning how to operate the vehicle and we’re learning all of the things required to get us ready to fly,” Sarafin said. “We’ve demonstrated a large number of those things, not only through wet dress, and some of the other ground tests that we’ve had, but we are still learning as we go — again — to get this vehicle off safely.”
Nelson said that while everyone involved was disappointed and wanted to see a launch Saturday, there has been no pressure to speed up efforts, and the future human missions stay on target. He also said costs for each failed launch attempt pale in comparison to the alternative.
“Two scrubs is a lot less than a failure,” he said.