NASA mission managers said Artemis II is targeting November 2024 as it goes through issues found from the Artemis I mission including an unexpected heat shield performance during the 5,000-degree reentry.
The un-crewed Artemis I flight saw the successful launch of the Space Launch System rocket on Nov. 16 becoming the most powerful rocket to ever bring a payload to space. It sent the Orion capsule on a 25 1/2-day mission to orbit the moon traveling 1.4 million miles before its return to Earth on Dec. 11 coming in faster than any previous human-rated spacecraft at 24,500 mph.
Artemis II, though, looks to put humans on board the Orion capsule, and just how well the spacecraft can keep its passengers safe is at the top of NASA’s concerns.
NASA Orion Program manager Howard Hu said while it fell within safety parameters, the ablative surface coating of the heat shield, meaning material meant to evaporate or melt away as it hits the atmosphere, was instead coming off in chunks.
“So part of that heating to 5,000 degrees Fahrenheit that you will encounter on a reentry up to that temperature, you’re going to see a charring of that material, a kind of what you do when you barbecue. … So that’s expected to happen. That was planned,” he said. “Now what normally happens as you get charring, you’ll have losses through a chemical reaction. Some of it we’re seeing is larger, like more of little pieces that are coming off as opposed to being ablated.”
He was reticent to say it was an issue that would require changes for the Artemis II mission, but wants to take all of the sensor data and work through the difference in computer models on what was expected vs. what actually happened. He noted the models can only be formed on what can be simulated on Earth, and so the actual behavior during a space launch and landing just might be different.
“It may be just part of what the heat shield is, and what we would expect as we return from the moon,” he said. “So it’s very early for us to think about any potential solutions to address any additional char loss or liberation.”
So teams will continue to assess the data while moving forward on all the other moving parts of Artemis II for its target launch of late 2024.
Next up is continued testing on the Orion crew capsule and European Service Module for Artemis II, both already on site at Kennedy Space Center. Already, avionics hardware that flew on Artemis I has been removed and reinstalled on the Artemis II capsule. Also in place are the pieces needed for humans including hand controls, displays, life support and thermal control systems.
“The teams down there are preparing for the engine section to be joined to the rest of the four-fifths of the rocket,” said SLS Program manager John Honeycutt. “That’s the last major element of the core stage to be joined and then the four RS-25 engines will be integrated into the engine section.”
The former Space Shuttle Program engines are combined with two solid rocket boosters to provide the SLS’s 8.8 million pounds of thrust on liftoff. Those boosters are already packaged and ready to be brought to KSC by train from Utah.
The last part of the puzzle, though, is the Mobile Launcher, which is managed by NASA’s Exploration Ground Systems. The SLS and Orion can’t be stacked for launch until the Mobile Launcher (ML) goes through more repairs it suffered from the Artemis I launch, and also completes more testing back at KSC’s Launch Pad 39-B, including testing of the emergency escape system that needs to be in place for the astronauts.
The plan, though, sees everything in place at KSC’s Vehicle Assembly Building by December with stacking operations in the early months of 2024 and integrated operations in June or July of summer 2024, Quinn said. Unlike Artemis I, the next mission will only go through a tanking test, but not a series of full wet dress rehearsals.
“We’re pressing ahead with putting the vehicles together, building them up while we’re looking at the data from Artemis I,” Free said. “That hasn’t changed our planned launch date.”
NASA’s standing target for Artemis II was that it would fly no earlier than May 2024, but even as Artemis I completed its mission in December, missions managers kept saying it would be more of an expected two-year turnaround. The names of the four crew to fly are expected to be announced before the summer.
Despite the time between the first two launches, Free said NASA is still on schedule to launch Artemis III by November 2025. That’s the mission that would return humans including the first woman to the lunar surface, but is reliant on SpaceX to develop and certify its new Starship as the Human Landing System for that mission as well as Axiom Space to develop spacesuits that will keep them safe.
“Our plan has always been 12 months, but there are significant developments that have to occur,” Free said. “That’s just the nature of trying to land people on the moon.”