The Space Launch System rocket and Orion spacecraft continue to sit on the launch pad at the Kennedy Space Center in Florida.
Since the second launch attempt of the unmanned Artemis I mission on September 3, engineers have replaced two seals on the interface of the liquid hydrogen fuel line between the rocket and the mobile launcher, according to NASA officials. These seals were associated with a large hydrogen leak that resulted in the rubbing of the launch attempt.
When engineers replaced the seal on an 8-inch (20 cm) diameter rapid-separation line for hydrogen, Artemis mission manager Mike Sarafin said at a NASA press conference Monday that they found a gap.
The indentation was less than 0.01 inch (0.3 mm), but It allows compressed gas to escape, which can be very dangerous due to the flammability of hydrogen when it meets air. The team believes the dent is related to the leak, but test results can confirm that.
Test ‘nice’ actions
The cryogenic demonstration is intended to test seals and use updated “gentle and gentler” loading procedures for the ultra-cooled propellant, which the rocket will test on launch day.
said Jeremy Parsons, deputy director of NASA’s Earth Exploration Systems Program at Kennedy Space Center.
The gentler, more gentle loading procedure is to reduce the pressure rises and thermal rises seen during previous launch attempts. To achieve this, the team will slowly raise the pressure on the liquid hydrogen storage tank. It’s estimated that the slower procedure adds no more than 30 minutes to the process, Parsons said.
“It’s going to be a very slow, steady incline,” Parsons said. “So (we) are just trying to slowly introduce some of those thermal differences and reduce the thermal shocks and pressure.
Liquid oxygen is relatively dense, about the density of water, and is pumped into the rocket. Meanwhile, hydrogen is very light, so it is stirred up using pressure rather than being pumped, said Tom Whitmer, associate deputy director of NASA’s Joint Exploration Systems Development.
Whitmer said the new loadings will use a slower compression rate with gradual temperature changes.
The test will also include engine bleed, which cools the engines upon launch. The mission team removed the first attempt to launch Artemis I on August 29 due to a faulty sensor issue that occurred during this hemorrhage.
After both liquid oxygen and liquid hydrogen reach the regeneration stage — because some of the ultra-cooled propellants wear off — the team will conduct a pre-compression test.
According to NASA officials, “the test will raise the liquid hydrogen tank to the pressure it will experience just before launch while engineers calibrate the settings to adapt the engines to a higher flow rate, as will be done during the final count.” “Performing stress testing during the demo will enable teams to connect to the necessary settings and validate schedules prior to launch day, reducing schedule risk during the launch countdown.”
Getting ready to go
If cryo testing goes well, the next launch could be attempted on Tuesday, September 27, with a 70-minute window opening at 11:37 a.m. ET. Mission managers will meet to discuss test results on September 25 to assess a possible launch date.
The Artemis team receives daily briefings on Hurricane Fiona in case it has any bearing on whether the missile assembly should be returned to the Vehicle Assembly Building, a process that can take three days.
If Artemis I launches on September 27, it will go on a 39-day mission and return to Earth on November 5. It is possible that there will be another backup release date of October 2. While NASA recommends these launch dates, the team ultimately depends on a decision from the US Space Force, which will need to issue a launch waiver.
The US Space Force, a military arm, still oversees all missile launches from the US East Coast, including NASA’s Florida launch site, and this area is known as the Eastern Range.
Range officials are tasked with making sure there is no danger to people or property on any launch attempt.
The Artemis team continues to have “productive and collaborative” discussions with the Eastern Range, and NASA is sharing additional detailed information requested by the Space Force for review.
“We’ll go when we’re ready,” Sarafin said. “But in terms of the flight reward of this flight, we have said from the beginning that this is the first in a series of increasingly complex missions, a purposeful stress test of the rocket.”
“We’re helping direct humanity’s global movement into deep space,” Jim Frey, NASA associate administrator for the Exploration Systems Development Mission Directorate, said in a statement.
“The goals will help ensure a long-term strategy for solar system exploration that can keep purpose consistent and change policy and funding.”
CNN’s Jackie Wattles contributed to this story.
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