The next opportunity for the agency to begin refueling the 98-meter Artemis I rocket stack, including NASA’s space launch system and the Orion spacecraft, is on Monday.
“We fixed it and reconfigured it from where we were earlier today,” Artemis Launch Director Charlie Blackwell-Thompson said during a news conference Sunday. “Our team got together and laid out our plan for how we’re going to get back to filling up tomorrow so it’s all worked out.”
The team is still working on fixing the fan issue and hope to find a solution tonight. If that goes according to plan, they will continue to fuel the rocket at 7:00 am ET Monday and begin the countdown at around 2:40 pm ET.
Known as the wet dress rehearsal, the test began Friday afternoon at 5 p.m. ET.
The wet dress rehearsal simulates every phase of launch without the rocket actually leaving the launch pad. This includes powering up the SLS rocket and the Orion spacecraft, loading super-cold propellant into the rocket tanks, going through a full countdown simulating launch, resetting the countdown clock, and emptying the rocket tanks.
Operations were halted Sunday before propellants were loaded into the rocket’s core stage “due to the loss of the ability to pressurize the mobile launcher,” according to an update shared by the agency.
Primary and redundant supply fans for the mobile launcher were malfunctioning and each encountered different issues, Blackwell-Thompson said.
“The fans are needed to positively pressurize the enclosed areas within the mobile launcher and keep out hazardous gases. Technicians cannot safely proceed with propellant loading into the rocket core stage and intermediate cryogenic propulsion stage without this capability.”
The fans ensure gases don’t build up and cause fire hazards or an increase in hazards, Blackwell-Thompson said.
Ahead of this Sunday afternoon release, Artemis I survived a strong thunderstorm at the Kennedy Space Center on Saturday.
Four lightning strikes hit the lightning towers around Launchpad 39B. While the first three hits were low intensity on tower two, the fourth hit was much more intense and hit tower one.
When these impacts took place, the Orion spacecraft and the SLS rocket core stage were powered up. The rocket’s preliminary cryogenic propulsion stage and boosters were not.
The fourth hit was quite rare because it was a positively charged cloud to the ground hit and much stronger than the others, according to NASA weather experts.
Each of the towers is topped with a fiberglass mast and a series of catenary or catenary wires, wires and ladders that help deflect lightning strikes from the missile, Parsons explained. This new system offered stronger shielding than that used during the shuttle program. It also features a suite of sensors that can determine the missile’s condition after lightning strikes, eliminating days of delays caused when teams need to assess the missile.
“We don’t believe that (fan issue) is related to the storm or the lightning event,” Blackwell-Thompson said. “It continued to run normally during the storm activity. And then it ran for several hours this morning before there was a problem.”
Despite the strikes and delays, the team was prepared to continue Sunday’s rain dress rehearsal until they encountered the fuel issue.
Parsons shared a reminder that this is the point of the wet dress rehearsal – working out the kinks of a new system before launch day.
“One nice thing about this being a test and not starting today is that we have flexibility with the testing window to address issues first time,” Parsons tweeted.
“We are having many new experiences as we prepare for the Artemis I mission in particular,” said Mike Sarafin, Artemis Mission Manager, during the press conference. “And one of the new experiences was literally watching a 32 story rocket standing out there and being struck by lightning with this lightning protection system. It protected the vehicle perfectly.”
“The team is prepared, we just have to solve a few technical issues,” added Sarafin. “They have shown incredible discipline and tenacity and I am confident that we will achieve that soon.”
The results of the wet dress rehearsal will determine when the unmanned Artemis I will launch on a mission that will go beyond the Moon and return 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 colored person on the lunar surface by 2025.
What to expect next
When the wet rehearsal resumes, it will be a matter of loading the rocket with more than 700,000 gallons (3.2 million liters) of super-cold propellant — the “wet” in the wet rehearsal — and then the team will go through all the steps up to go through start .
“Some venting may be seen during refueling,” the agency said, but that’s about it for visible action on the launch pad.
Team members count down to one minute and 30 seconds before the start and pause to ensure they can pause the start for three minutes, resume and let the clock count down to 33 seconds and then pause the countdown.
They then set the clock back to 10 minutes before launch, and counted down again, ending at 9.3 seconds, just before ignition and launch would occur. This simulates what is known as scrubbing a launch, or aborting a launch attempt when weather or technical problems would prevent a safe launch.
At the end of the test, the team drains the rocket’s fuel, just like a real scrub.
Depending on the result of the wet dress rehearsal, the unmanned mission could start in June or July.
During the flight, the unmanned Orion spacecraft will launch on the SLS rocket to reach the moon and travel thousands of kilometers beyond it – further than any spacecraft designed to carry humans has ever traveled. This mission is expected to last a few weeks and end with Orion landing in the Pacific Ocean.
Artemis I will be the last testing ground for Orion before the spacecraft takes astronauts to the Moon, which is 1,000 times farther from Earth than where the International Space Station is located.
After the unmanned Artemis I flight, Artemis II will be a manned moon flyby, and Artemis III will return astronauts to the lunar surface. The schedule for subsequent mission launches depends on the results of the Artemis I mission.