Artemis II Mission Provides Insights on Radiation and Health Effects in Space

NASA Administrator says no unexpected conditions were observed during the 10-day moon mission.

Apr. 16, 2026 at 12:37am

Got story updates? Submit your updates here. ›

A highly structured abstract painting in soft blues, greens, and grays, depicting sweeping geometric arcs and precise anatomical spirals, conceptually representing the complex forces of radiation and their impact on the human body in the vacuum of space.An abstract visualization of the radiation hazards faced by astronauts during long-duration space missions, a key focus of the Artemis II data analysis.Today in Orlando

The successful Artemis II mission, which saw astronauts travel around the moon for the first time in over 50 years, will provide valuable data on the long-term health effects of radiation exposure in space. While the heat shield on the Orion capsule appeared to perform as expected, NASA and health experts caution that the full impact on the astronauts' health may not be known for several years.

Why it matters

The Artemis II mission is a crucial step towards future long-duration space exploration, including potential missions to the moon and eventually Mars. Understanding the radiation and health risks faced by astronauts is critical to ensuring their safety and wellbeing during these ambitious endeavors.

The details

Photos show the Orion capsule's heat shield performed well during the fiery reentry, but NASA Administrator Jared Isaacman cautioned that a full data review is still needed. The heat shield is designed to protect astronauts from extreme heat and radiation, which can cause both short-term and long-term health effects. Radiation exposure can lead to skin burns, damage to the immune system and bone marrow, and potential cognitive issues if it reaches the brain. While the 10-day Artemis II mission was relatively short, longer future missions could result in more severe deconditioning of the heart and muscle mass loss due to the lack of gravity.

  • Artemis II astronauts safely splashed down off the West Coast on April 11, 2026 after their 10-day mission.
  • NASA is currently reviewing the data from the Orion capsule, which will be brought back to Kennedy Space Center.

The players

Jared Isaacman

The NASA Administrator who commented on the Artemis II mission performance.

Dr. Tomas Dvorak

A radiation oncologist at Orlando Health who discussed the potential long-term health effects of radiation exposure in space.

Dr. Srinivas Prasad

An interventional cardiologist at Orlando Health who spoke about the impact of microgravity on the heart.

Got photos? Submit your photos here. ›

What they’re saying

“I'm hesitant to get ahead of a proper data review, but I understand the space community's curiosity. Adding no unexpected conditions were observed.”

— Jared Isaacman, NASA Administrator

“If it passes through the skin, which it would, then you can get a skin burn from that potentially. That's usually mild, but sometimes can be pretty significant.”

— Dr. Tomas Dvorak, Radiation Oncologist, Orlando Health

“For future missions, certainly those that are longer, it might be like you're in a cast and you would lose a lot of muscle mass. That's not dangerous for the heart per se, but the loss of muscle mass and deconditioning of the heart would cause its inability to handle big loads when it comes back to Earth.”

— Dr. Srinivas Prasad, Interventional Cardiologist, Orlando Health

What’s next

The Orion capsule will be brought back to Kennedy Space Center, where several data analysis will be performed to fully understand the radiation exposure and health impacts on the Artemis II astronauts.

The takeaway

The Artemis II mission is a critical step towards future long-duration space exploration, and the data collected on radiation exposure and its health effects will help ensure the safety and wellbeing of astronauts on upcoming missions to the moon and beyond.