The agency’s next opportunity to begin supplying the 322-foot (98 m) Artemis I rocket stack, including NASA’s Space Launch System and Orion spacecraft, will be Monday.
“We’ve fixed and remodeled what we had earlier today,” Artemis launch director Charlie Blackwell Thompson said during Sunday’s press conference. “Our team met and put together our plan for how we would get back to the tanks tomorrow, so that was all laid out.”
The team is still working on the fan issue and hopes to find a solution this evening. If all goes according to plan, they will resume missile launches at 7 a.m. ET on Monday and begin the countdown at approximately 2:40 p.m. ET.
The audition, known as the wet dress rehearsal, began Friday afternoon at 5 p.m. ET.
The rehearsal simulates each stage of the launch without the missile actually exiting the launch pad. This includes powering up the SLS rocket and Orion spacecraft, loading ultra-cooled propellant into the rocket’s tanks, performing a full launch simulation countdown, resetting the countdown clock, and drying the rocket tanks.
Operations were halted Sunday before propellant was loaded into the rocket’s core stage “due to a loss of pressure capacity on the mobile launcher,” according to an update published by the agency.
Blackwell-Thompson said the mobile operator’s main and frequent supply fans were not working properly and each had different problems.
“The propellers are needed to provide positive pressure on the enclosed areas within the mobile launcher and keep out dangerous gases. Technicians cannot safely proceed with loading propellant into the rocket’s primary stage and the temporary cryogenic propulsion stage without this capability.”
Blackwell-Thompson said the fans ensure that gases do not build up and cause a fire or increased risk.
Prior to that number on Sunday afternoon, Artemis I survived a strong thunderstorm at the Kennedy Space Center on Saturday.
Four lightning strikes struck the lightning towers within the vicinity of Launchpad 39B. While the first three strikes were low in intensity for the second tower, the fourth blow was more intense and hit the first tower.
When these strikes occurred, the Orion spacecraft and SLS rocket stage were turned on. The temporary cryogenic propulsion stage of the rocket and boosters was not.
The fourth hit was somewhat rare, because it was a positively charged cloud into a ground strike and much more powerful than the other hit, according to NASA weather experts.
Each of the towers is surmounted by a fiberglass mast and a series of wires and overhead or chain conductors that help divert lightning strikes away from the missile, Parsons explained. This new system provided more armor than was used during the Shuttle program. It also has an array of sensors that can determine the state of the missile after lightning strikes, preventing days of delays that occur when teams have to assess the missile.
“We don’t believe that (the fan issue) was related to the storm or the lightning event,” Blackwell Thompson said. “It continued to operate normally during storm activities. Then this morning it was up and running for several hours before it had a problem.”
Despite the blows and delays, the team was ready to continue rehearsal on Sunday until they faced the problem of tanks.
Parsons shared a reminder that that’s the point of the wet clothes rehearsal—working out the kinks of a new system before launch day.
“The nice thing about this being a test, not launching it today, is that we have flexibility with the test window to deal with first-time issues,” Parsons tweeted.
“We have a lot of new experiences where we’ve set up the Artemis I mission in particular,” said Mike Sarafin, Artemis mission director, during the press conference. “One of the new experiences was watching a 32-story rocket sitting there with a lightning bolt around it using the lightning protection system. It did a perfect job of protecting the car.”
“The team is ready for that, all we need is to solve some technical problems,” Sarafin added. “They have shown incredible discipline and toughness, and I’m confident we’ll get there soon.”
The results of training in wet clothes will determine when Artemis I will embark on a mission beyond the Moon and back to Earth. This mission will launch NASA’s Artemis program, which is expected to return humans to the moon and land the first woman and first people of color on the moon by 2025.
What do you expect next
When rehearsal resumes, it will involve loading the rocket with more than 700,000 gallons (3.2 million liters) of supercooled fuel — “wet” at rehearsal — after which the team will go through all the steps toward launch.
“Some venting may be seen during venting,” according to the agency, but this is related to what is visible on the launch pad.
Team members will count down the 1 minute 30 seconds before launch and pause to make sure they can keep running for three minutes, resume running the clock and let it go down to 33 seconds, then pause the countdown.
Then, they’ll reset the clock to 10 minutes before launch, countdown again and finish in 9.3 seconds, just before ignition and triggering occur. This simulates what’s called a launch purification, or aborted launch attempt, if weather or technical issues would prevent a safe takeoff.
At the end of the test, the team will drain the rocket’s propellant, just as it would during a real cleanup.
Depending on the outcome of the rehearsal, the unmanned mission could begin in June or July.
During the flight, the unmanned Orion spacecraft will blast above an SLS rocket to reach the moon and travel thousands of miles behind it — farther than any spacecraft intended to carry humans has traveled. This mission is expected to last a few weeks and will end with Orion spray in the Pacific Ocean.
Artemis I will be Orion’s final testing ground before the spacecraft carries astronauts to the Moon, 1,000 times more Earth-bound than the International Space Station site.
After the uncrewed Artemis I flight, Artemis II will be a lunar flight, and Artemis III will return astronauts to the lunar surface. The schedule for launching subsequent missions depends on the results of the Artemis I mission.