FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-13/23

Title and Subtitle: Occupational Exposure to Ionizing Radiation for Crews of Suborbital Spacecraft: Questions and Answers

Report Date: December 2013

Authors: Copeland K

Abstract: Crewmembers on future suborbital commercial spaceflights will be occupationally exposed to ionizing radiation, principally from galactic cosmic radiation. On infrequent occasions, the sun or thunderstorms may also contribute significantly to the ionizing radiation received during such travel. Altitudes of suborbital spacecraft flights are too low for trapped radiation in the Van Allen belts to be of concern. Ionizing radiation consists of subatomic particles that, on interacting with an atom, can cause the atom to lose one or more orbital electrons or even break apart its nucleus. Such events in body tissues may lead to health problems.

For suborbital spaceflight crews and their children irradiated in utero, the principal health concern from occupational radiation exposure is a small increase in the lifetime risk of fatal cancer. Both of these groups also risk passing genetic defects to future generations.

Other health risks are also associated with exposure to low levels of ionizing radiation. The FAA recommends occupational ionizing radiation exposure limits for crewmembers and is developing computer software for estimating the amount of ionizing radiation received on a flight.

Key Words: Spacecraft, Crewmembers, Ionizing Radiation, Galactic Cosmic Radiation, Solar Cosmic Radiation, Cancer Risk, Hereditary Risks, Radiation Exposure Limits

No. of Pages: 13