NASA is once again delaying its Artemis missions to the Moon. The US space agency announced on Friday it is now targeting an April 2026 launch for its Artemis II mission and mid-2027 for Artemis III. This marks another schedule shift to the missions due to technical and logistical challenges.

The latest delay stems from issues with the Orion spacecraft's heat shield, which experienced an unexpected loss of charred material during the reentry of the Artemis I uncrewed test flight in December 2022. Following an independent review and extensive analysis, NASA determined its heat shield's Avcoat material did not adequately vent gases, causing cracks and material loss.

While NASA determined that astronauts would have been safe on board Artemis I, the agency emphasized the need to eliminate potential risks to ensure mission success.

"The Artemis campaign is the most daring, technically challenging, collaborative, international endeavor humanity has ever set out to do," NASA Administrator Bill Nelson said in a statement. "We need to get this next test flight right. That's how the Artemis campaign succeeds."

At the same time, NASA said it will continue preparing its Space Launch System rocket, stacking its elements -- a process that began in November -- to ensure compatibility with the Orion spacecraft for Artemis II.

The Artemis II mission will be a 10-day crewed test flight around the Moon and back, collecting crucial data on the performance of the Orion spacecraft. This includes monitoring the air revitalization system, testing manual flying capabilities and evaluating how the crew interacts with onboard hardware and software -- critical steps in preparing NASA for the Artemis III mission. 

That mission will land astronauts, including the first woman and the first person of color, on the Moon's South Pole. Humans have not landed on the moon since NASA's Apollo 17 mission in 1972.