First astronaut missions to the Moon since 1972 delayed due to heat shield questions, hardware readiness

The Artemis 2 crew, standing in from of their Artemis spacecraft, discusses their planned around-the-moon flight with reporters at the Kennedy Space Center. Left to right: commander Reid Wiseman, Victor Glover, Christina Koch and Canadian astronaut Jeremy Hansen. Image: Adam Bernstein/Spaceflight Now.

A quartet of astronauts will have to wait until next year before their voyage around the Moon. In a robust update on Tuesday afternoon, NASA leadership announced that the next two missions in the Artemis program, and the first featuring astronauts, will each shift back by nearly a year.

The Artemis 2 mission, which was due to liftoff from the Kennedy Space Center this November, will instead launch no earlier than September 2025. The Artemis 3 mission, which will still feature the first crewed Moon landing since 1972, is now pushed to September 2026 at the earliest.

“As we remind everybody at every turn, safety is our top priority,” said NASA Administrator Bill Nelson. “And though challenges are clearly ahead, our teams are making incredible progress.”

The delay of the Artemis 3 mission was forecast in November in a report to Congress from the U.S. Government Accountability Office (GAO). That report suggested that landing back on the Moon was likely to actually happen in early 2027 “if development took as long as the average for NASA major projects.”

There are a few main items that are causing the first crewed missions of the Artemis program to shuffle back from their planned launch dates. There is the matter of some outstanding unknowns regarding the heat shield that protects the Orion crew capsule, there is some hardware that needs to be removed and replaced on Orion and the items needed to explore the Moon’s surface, namely spacesuits and the lander, are both behind schedule.

“As you heard leading up to Artemis 1, as we’ll talk about for Artemis 2 and future missions, these are flight tests,” said Jim Free, NASA’s new associate administrator. “Developing, testing and learning and improving our knowledge is what we’re doing and ensuring that when we do fly, we’ll be successful.”

During his opening remarks, Amit Kshatriya, the deputy associate administrator for the Moon to Mars Program and the Exploration Systems Development Mission Directorate, said they have three priorities as they step through this work:

  1. Safety
  2. Making comprehensive, methodical progress towards objectives
  3. Learning from data gathered during flight test

Lingering questions, lessons learned

More than a year after the conclusion of the Artemis 1 mission, one key item that still needs to be further worked: the heat shield. Kshatriya said upon studying the heat shield, they saw what he described as “off-nominal recession of some char that came off the heat shield.”

The Orion crew capsule uses a skip maneuver to help deal with the nearly 5,000-degree Fahrenheit temperature that builds up as the capsule returns through the Earth’s atmosphere at a blistering 25,000 miles per hour. Kshatriya said that some pieces of the heat shield came off during the first phase of the skip reentry.

“When I talk about it, it makes it sound like there’s some big chunks coming off the vehicle. That’s not correct,” said Kshatriya. “We’re still piecing together that overall timeline. Of course, it’s very tough, based on the assets we had, to identify each and every one, but we did. We went frame-by-frame, through every piece of video that we have from Orion, and from our external assets, to determine when the initiation of that char liberation began. And it was after we started climbing out of that first dive into the skip.”

Inside the Multi Payload Processing Facility at NASA’s Kennedy Space Center in Florida, engineers and technicians conduct inspections of the heat shield on the Orion spacecraft for the Artemis I mission. Orion returned to Kennedy on Dec. 30, 2022, after splashing down in the Pacific Ocean on Dec. 11 following a 25-day mission around the Moon. Image: NASA

He said while charring was expected — the heat shield is made of ablative material — Kshatriya said they were not expecting it to be stripped away. In response to a reporter’s question, he noted that had crew been onboard during the Artemis 1 mission, they wouldn’t have sensed anything was amiss from inside Orion since there was no excessive heating within the cabin.

Kshatriya said even though it appeared crew safety wasn’t threatened, they don’t want to make any assumptions moving forward without more comprehensive data. A review to determine the root cause of the issue lasted most of 2023 and is still ongoing.

“We have to synthesize that data and update the overall thermal, mechanical and material models of that heat shield to make sure that before we attempt reentry from a second lunar return mission, like we’ll have from Artemis 2, that we’re 100 percent confident that we understand he performance of that heat shield,” Kshatriya said.

Other Orion obstacles

The heat shield that protects the astronauts during the reentry process is not the only issue that the Lockheed Martin-built spacecraft is up against. Multiple crew modules are in flow at NASA’s Kennedy Space Center and during work on the capsule for the Artemis 3 mission, teams discovered that some of the circuitry was faulty.

Kshatriya said that the same components passed acceptance testing ahead of being installed on the spacecraft to be used for the Artemis 2 mission, but failed inspection for Artemis 3.

He said they discovered a design flaw in the circuit that is used in critically important life support systems, the carbon dioxide scrubber, in particular.

“Once we looked at the rationale for potentially using the system as is, it became very clear to use that it was unacceptable to accept that hardware and we have to replace it,” Kshatriya said. “Given the current configuration with the spacecraft, the access to those components… it’s going to take us quite a bit of time to get to. Every connector that we touch as part of that replacement operation will have to be tested after we’re done and we’ll have to put the vehicle through a full functional testing afterwards.”

Kshatriya said the replacement process was the main driver for the new September 2025 target launch date for the Artemis 2 mission.

Beyond that, Kshatriya said, unlike the first flight of Orion and SLS, Artemis 2 will feature an integrated abort capability. He said Orion has been qualified to survive a rapid escape away from the Space Launch System rocket, but there are some questions remaining regarding the mechanics of the system.

“We have found a few cases where we do believe there could be some deficiencies in the performance of the electrical system, in particular, some of the batteries that we need to make sure we understand how they’re enduring those environments,” he said. “So, we’re still very early in that investigation. We have not yet developed a forward path. We have multiple parallel options to fix this issue.”

Spacesuits and human-rated landers

In addition to the issues delaying the Artemis 2 mission, the Artemis 3 flight has its own, unique set of challenges. NASA leaders confirmed that for now, this will still be a crewed landing on the Moon’s South Pole, which means both the lander and the space suits need to be ready.

SpaceX was granted a $2.89 billion contract to help develop its Starship rocket as a human-rated lander. In order to get the lander to the Moon’s surface and back up again, SpaceX will need a series of propellant transfer missions to fuel a tanker that will remain on orbit around the Earth. That tanker will then shift its fuel to the Human Landing System (HLS) version of Starship, which will rendezvous with the Orion spacecraft in orbit around the Moon.

During Tuesday’s teleconference, Jessica Jensen, the vice president of customer operations at SpaceX, said it would take about 10 launches of Starship to fully fuel an on-orbit tanker.

“That would be my rough guess right now, but it could be lower depending on how well the first flight tests go or it could be a little bit higher,” she said.

Starship thunders away from its launch pad, trailing a one thousand foot exhaust plume. Image: Adam Bernstein/Spaceflight Now.

In 2023, SpaceX launched its first two flight tests of its fully integrated Starship rocket from its Starbase facility near Boca Chica Beach in southern Texas. Jensen said the hardware for their third test flight should be ready later this month and they anticipate getting approval from the U.S. Federal Aviation Administration for a launch in February.

Jensen said there will be a propellant transfer demonstration within a singular Starship vehicle “where the goal is to transfer propellant from the header tank into the main tank.”

There will also be an uncrewed test landing on the Moon using Starship, which is now set for 2025.

The other big, outstanding development item for the Artemis 3 mission are the spacesuits that will be worn for the first time on the Moon. Free said that NASA and Axiom Space were completing the preliminary design review for Artemis 3.

“What we found out in that review process and their supply chain setup is some of what has also influenced the [Artemis 3 launch] date,” Free said.

What comes next?

In addition to all of the work that NASA and its partners are doing, there are still some other outstanding assessments that need to be made. Ahead of the Artemis 4 mission, which remains scheduled for September 2028, NASA needs to launch the Power Propulsion Element (PPE) and the Habitation and Logistics Outpost (HALO) modules for the Gateway space station.

Kshatriya said the plan was to launch the two in October 2025, but that is now being shifted as well.

“We’re now working with our industry partners at Maxar and Northrop Grumman to review the schedule for when it makes sense to launch that before Artemis 4,” Kshatriya said. “We believe they have a great path to get us there to support that mission, but we will be updating that schedule as well. We’re doing what we can to make sure our partners have the time to do the development correctly and safely.”

The Power and Propulsion Element’s 12 kw thrusters will make Gateway the most powerful solar electric spacecraft ever flown. Graphic: NASA

Artemis 4 was previously delayed in part to accommodate delays in the schedule for the upgraded Mobile Launcher platform and tower, which is needed to support the larger SLS Block 1B rocket.

Congressional leaders on Capitol Hill are among those closely tracking the progress of the Artemis program. In a statement on Tuesday evening, Democrats Zoe Lofgren and Eric Sorensen, the ranking members of the House of Representatives Committee on Science, Space and Technology, said the committee will be holding a hearing next week to discuss “the cause and costs of the delays.”

“While we are disappointed to learn of an Artemis delay today, we stand by NASA in their commitment to safety,” said Lofgren and Sorensen in a statement. “We support Artemis and its goal to return astronauts to the Moon; we want these missions to be safe and successful. As we move forward to ensure Artemis stays on track, we must understand the challenges of this complex effort and its delays.”

“The Artemis Program holds tremendous importance to our nation. It will inspire the next generation, strengthen our industry and international partnerships, and demonstrate capabilities needed for eventually sending humans to Mars.”