NASA engineers counted down the T-40 minutes while fixing the problem for over an hour. Finally, director Charlie Blackwell-Thompson comes out call effort a cleansing. At a press conference the next day, members of the Artemis team suggested that the apparent engine problem might actually be the sign of a dodgy temperature sensor. “The way the sensor works is inconsistent with the physics of the situation,” said John Honeycutt, SLS program manager.
The launch was then pushed back to this weekend, with countdown procedures starting again early Saturday morning. Anticipating challenges with the propulsion, they began the relaxation process, including the warm-up test, about 45 minutes before the countdown. The launch team and weather staff confirmed that the weather could be suitable for launch, although there were some intermittent showers. They began filling the large orange fuel tank with more than 700,000 gallons of liquid hydrogen and liquid oxygen, which were supercooled to -423 and -297 degrees Fahrenheit.
But that is when the hydrogen leak occurs, after the oxygen has been supplied most of the time. “Hydrogen is difficult to work with,” said Jim Free, deputy administrator at NASA headquarters. The leak appears to come from a seal in the 8-inch quick disconnect, a coupling used for the line that supplies liquid hydrogen from the ground system. Eventually, it became clear that the coupling would have to be removed and replaced.
At 11:17 a.m. Eastern time, Blackwell-Thompson made a call to check on the launch attempt.
In an industry where “space is tough” is a cliché, such delays are not uncommon, even when the weather cooperates. During NASA’s space shuttle program, several successful launches ended up having to be postponed multiple times. With the SLS – an all-new, extra-large missile with multiple coordination systems – the task becomes even more formidable. NASA has 489 “launch commitment criteria” that must be met before they can “go” to launch, Sarafin said in a press conference on September 1.
NASA may need to delay the Artemis launch until mid-October, after SpaceX’s Crew-5 launch at a neighboring pad—which has also been delayed several times. That mission will take two NASA astronauts, a Japanese astronaut and a Russian cosmonaut, Anna Kikina, to the International Space Station. This will be the first time a Russian has flown on a US-made spacecraft since conflict in Ukraine lead to stress between Roscosmos, NASA and other space agencies.
The team is still looking into whether repairs can be made on the launch pad or if the rocket has to be rolled back to the Vehicle Assembly Building. “There is a risk versus a risk tradeoff,” Sarafin said, noting that keeping the rocket on the launch pad would expose it to environmental risks, but that the quick disconnect seal could not be tested at cold temperature inside the building.
Backtracking is not without risk in itself, as movement and vibration can stress the rocket. But to minimize wear and tear, the rocket will travel no faster than 1 mph on a machine called “crawler. That payback option would warrant a delay until the end of October, which could also pose a risk to the small spaceship on rocket, for their own small tasks. Those spacecraft, called CubeSats, have batteries with limited power – some of them can be recharged, but others are not. “If we need to go back to the Vehicle Assembly Building, we can replace the batteries for some of them,” Sarafin said at the press conference. “It’s part of the process of looking at a certain launch time.”
Nelson emphasized that Artemis 1 was a test flight and said that today’s setback is not expected to affect the overall progress of the program, which aims to put astronauts into orbit. Moon aboard Artemis 2 in 2024 and send them to the moon aboard Artemis 3 in 2025. (However, that moon landing mission could slip until 2026, according to a March 1. assessment of the inspector general of NASA.)
While the Artemis team wants to launch today, NASA officials stress that the rocket is in good condition and they say they are confident they will be able to launch safely in the near future. “We’re not where we want to be, except for the safe vehicle – it’s not safe in orbit, it’s safe on the ground,” Free said.
