NASA has already watched dormant herpes viruses, including the one behind chickenpox and shingles, reactivate in astronauts aboard the International Space Station. Artemis II has now carried that question into deep space: more than 252,000 miles from Earth, the crew collected saliva samples to test whether radiation, isolation and distance trigger the same hidden immune response beyond low Earth orbit.

For years, NASA has used the International Space Station to watch a quiet signal of astronaut stress: dormant herpes viruses becoming detectable again during spaceflight. That does not usually mean astronauts become ill. It means viruses that can persist silently in the body, including varicella zoster virus, the virus behind chickenpox and shingles, can reactivate [...] The post NASA has already watched dormant herpes viruses, including the one behind chickenpox and shingles, reactivate in astr