Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news about fascinating discoveries, scientific advancements and more.
Kennedy Space Center, Florida
NASA will not continue launching Artemis I for the remainder of the launch window, which ends Tuesday, according to an agency update after a second launch attempt was canceled on Saturday.
Future launch periods, including September and October, depend on what the team decides early next week, but that translates to minimal delays of at least several weeks.
“We won’t be launching during this launch window,” said Jim Free, associate administrator for NASA’s Exploration Systems Development Missions Directorate. “We are not where we wanted to be.”
Free said the stack, including the Space Launch System rocket and the Orion spacecraft, must return to the Vehicle Assembly Building unless they get a waiver from the lineup, which is managed by the ‘U.S. Space Force.
NASA Administrator Bill Nelson recalled that the shuttle was sent back to the Vehicle Assembly Building 20 times before launch – and noted that the cost of two scrubs is far less than one failure.
“We don’t pitch until we think it’s fair,” Nelson said. “These teams have been working on this and that’s the conclusion they’ve come to. I’m looking at this as part of our space program, where safety is at the top of the list.”
The scrub was called at 11:17 a.m. ET, three hours before the start of the launch window.
Artemis I was scheduled to take off on Saturday afternoon, but those plans were canceled after crew members discovered a liquid hydrogen leak that they spent most of the morning trying to fix. Liquid hydrogen is one of the propellants used in the rocket’s large central stage. The leak prevented the launch team from filling the tank with liquid hydrogen despite various troubleshooting procedures.
Previously, a small leak had been observed in this area, but it became a much larger leak on Saturday. The team thinks an overpressurization event may have damaged the soft seal of the liquid hydrogen connection, but they’ll have to look into it more closely.
“It was not a manageable leak,” said Artemis mission manager Mike Sarafin.
This is the second time in a week that the space agency has been forced to abort the launch countdown due to technical issues. The first launch attempt on Monday was canceled after several problems arose, including with a system meant to cool the rocket’s engines before liftoff and various leaks that occurred while the rocket was fueled.
The liquid hydrogen leak was detected Saturday at 7:15 a.m. ET in the quick-disconnect cavity that feeds the rocket with hydrogen into the core stage engine section. This was a different leak than what happened before Monday’s clean launch.
Launch controllers warmed up the line in an attempt to achieve a tight seal and the flow of liquid hydrogen resumed before a leak reoccurred. They stopped the flow of liquid hydrogen and proceeded to “close the valve used to fill and drain it, then increase the pressure on a ground transfer line using helium to attempt to re-seal it”, according to NASA.
This troubleshooting plan was not successful. The team again attempted the foreground to warm up the line, but the leak reoccurred after manually restarting the flow of liquid hydrogen.
There was a 60% chance the weather would be favorable for the launch, according to weather officer Melody Lovin.
The Artemis I stack, which includes the Space Launch System rocket and the Orion spacecraft, continues to sit on Launchpad 39B at Kennedy Space Center in Cape Canaveral, Florida.
The Artemis I mission is just the start of a program that will aim to bring humans back to the Moon and eventually land crewed missions on Mars. Nelson said problems during the first two scrubs caused no delays to future Artemis program missions.
This is how NASA wants to send humans back to the Moon
Over the past few days, the launch team has taken the time to address issues, such as hydrogen leaks, that surfaced ahead of Monday’s scheduled launch before it was cleaned up. The team also performed a risk assessment of an engine conditioning issue and a foam crack that also appeared, according to NASA officials.
Both were considered acceptable risks before the launch countdown, according to Artemis mission manager Mike Sarafin.
On Monday, a sensor on one of the rocket’s four RS-25 engines, identified as Engine No. 3, indicated that the engine could not reach the proper temperature range required for the engine to start on liftoff.
Engines must be thermally conditioned before super cold propellant passes through them prior to liftoff. To prevent the engines from experiencing temperature shocks, the launch controllers gradually increase the pressure of the central stage liquid hydrogen tank in the hours before launch to send a small amount of liquid hydrogen to the engines. This is called “bleeding”.
The team has since determined it was a bad sensor providing the reading – they plan to ignore the faulty sensor in the future, according to Space Launch Systems chief engineer John Blevins.
Once Artemis I launches, Orion’s journey will last 37 days as it travels to the moon, loops around it and returns to Earth – traveling a total of 1.3 million miles (2.1 million kilometres) .
Although the passenger list does not include any humans, it does have passengers: three mannequins and a stuffed Snoopy toy will ride Orion.
The crew aboard Artemis I may seem a bit unusual, but they each have a purpose. Snoopy will serve as a weightlessness indicator, meaning he will begin floating inside the capsule once it reaches the space environment.
The dummies, named Commander Moonikin Campos, Helga and Zohar, will measure deep space radiation that future crews might experience and test new armor suits and technologies. A biological experiment carrying seeds, algae, fungi and yeasts is also hidden inside Orion to also measure the reaction of life to this radiation.
Additional science experiments and technology demonstrations are also ring-mounted on the rocket. From there, 10 small satellites, called CubeSats, will detach and separate to collect information about the moon and the deep space environment.
Cameras inside and outside Orion will share images and video throughout the mission, including live views from the Callisto Experience, which will capture a feed of Commander Moonikin Campos seated in the commander’s seat. And if you have an Amazon Alexa-enabled device, you can ask it for the mission’s location every day.
Expect to see views of Earthrise similar to what was first shared during the Apollo 8 mission in 1968, but with much better cameras and technology.
The inaugural mission of the Artemis program will launch a phase of NASA space exploration that aims to land diverse crews of astronauts in previously unexplored regions of the moon – on the Artemis II and Artemis III missions, scheduled for 2024 and 2025 respectively – and ultimately deliver crewed missions to Mars.