mission team aiming to start Artemis I cryogenic demonstration tests Wednesday at 7:15 a.m., and NASA will share live coverage on its website. The Space Launch System rocket and Orion spacecraft sit on the launchpad at Kennedy Space Center in Florida.
Since the Artemis I mission’s second scrubbed launch attempt on Sept. 3, engineers have replaced two seals at an interface for the liquid hydrogen fuel line between the rocket and mobile launcher, according to NASA officials. These seals were associated with a large hydrogen leak, which led to the launch attempt being cleared.
When engineers replaced the seal on the 8-inch (20-centimeter) quick disconnect line for hydrogen, they found a “witness marker” or indentation on the seal attached to the foreign object debris, Artemis mission manager Mike Sarafin said. NASA press conference on Monday.
Sarafin said the team found no piece of debris, but the tooth was clean and pointed to a problem that contributed to the hydrogen leak.
Indentation 0.01 in. was under (0.3 millimeters), and This allows the pressurized gas to leak out, something that can be very dangerous given the flammability of hydrogen. The team believes the dent is linked to the leak, but test results can confirm this.
Sarafin said that on September 3, the large hydrogen leak was between two and three times the approved limit.
Testing ‘Kinder’ procedures
The cryogenic demonstration is intended to test seals and supercooled propellant using updated, “kinder and gentler” loading procedures that the rocket will experience on launch day.
Jeremy Parsons, deputy manager of NASA’s Exploration Ground Systems Program, said the Orion spacecraft and rocket booster will remain unpowered during the test, and the team does not intend to go into the terminal countdown or the last 10 minutes of the countdown before launch. . at Kennedy Space Center.
Kinder and gentler loading procedures are in place to reduce pressure spikes and thermal spikes seen during pre-launch attempts. To achieve this, the team will gradually increase the pressure on the liquid hydrogen storage tank. The process is estimated to take no more than 30 minutes, Parsons said.
“It’s going to be a very slow, steady ramp up,” Parsons said. “So (we’re) really trying to gradually introduce some of those thermal differences and reduce the thermal and pressure shock.”
Liquid oxygen is relatively dense, about the density of water, and is pumped into the rocket. Meanwhile, hydrogen is very light, so it is transferred using pressure rather than pumping it, said Tom Whitmeyer, NASA’s deputy associate administrator for general exploration systems development.
Whitmeyer said the new loading operations will use a slower rate of pressure with a more gradual temperature change.
Calls to the stations for testing, when all teams associated with the mission arrive at their consoles and report they are ready, begin today at 3 p.m. ET. The mission team anticipates getting a “go” to begin loading the rocket with propellant around 7 a.m. ET on Wednesday. If all goes well, the team expects testing to be complete by 3 p.m. that day, Parsons said.
The test will also include an engine bleed, which cools the engine for launch. The mission team reconstructed the first Artemis I launch attempt on 29 August primarily due to a problem with a faulty sensor during this bleed.
So far, the forecast looks promising for testing. The Artemis team is receiving daily briefings about Hurricane Fiona to see if it has any impact on whether the rocket stack needs to be moved back to the Vehicle Assembly Building, a process that could take up to three days.
If the cryo test goes well, the next launch attempt could take place on Tuesday, September 27, with a 70-minute window that opens at 11:37 a.m. Mission managers will meet on September 25 to discuss test results to assess a possible launch date.
If Artemis I launches that day, it will go on a 39-day mission and return to Earth on November 5. Another backup launch date is possible on October 2. Although these launch dates are recommended by NASA, the team ultimately relies on one. Decision by the US Space Force, which would require issuing a waiver for the launch.
The US Space Force, a branch of the military, still oversees all rocket launches from the East Coast of the United States, including NASA’s Florida launch site, and that area is known as the Eastern Range.
Range officers are tasked with ensuring that there is no danger to people or property from any launch attempt.
The Artemis team is continuing “productive and collaborative” discussions with Eastern Range, and NASA is sharing additional detailed information requested by the Space Force for review.
Whitmire said the team is taking it one step at a time and wants to test before making other decisions.
“We’re going to go when we’re ready,” Sarafin said. “But in terms of the reward of flying this flight, we’ve said from the outset that it’s the first in an increasingly complex series of missions, and it’s a purposefully stress test of the rocket.”
CNN’s Jackie Watts contributed to this story.