SPACE RADIATION What you can't see can kill you. I've worked around radiation sources, studied nuclear accident reports and more. Leaving the Earth's protective magnetic field increases radiation exposure on biologics and electronics by solar-cycle activity and Galactic Cosmic Radiation (GCR). GCR is responsible for the Apollo astronauts reporting seeing bright flashes without defined sources. As I dug into space radiation I discovered Robert Braeunig on November 2009 wrote "Apollo 11's Translunar Trajectory". One quote stands out in his publication: "Apollo 11's translunar trajectory as inclined, allowing the spacecraft to rise rapidly above the equatorial plane as it headed away from Earth. " This would indicate that NASA performed all Trans-Lunar Injections (TLIs) on the edge of the Van Allen radiation belts to avoid increased radiation. Although the Van Allen belts are weakest at the poles they are also the weakest points of the magnetosphere hence making them very strong points of entry for external radiation.
Further research let me to another subject - The South Atlantic Anomaly. All of our spacecraft avoids this region as much as possible. According to the American Geophysical Union it has been growing for years and now engulfs most of South America. Digging deeper I learned about Operation Argus, Starfish Prime and others - in the name of research we've done some insane things. From NASAs ISS page "NASA has adopted the recommendations of the National Council on Radiation Protection. Based on the Council's recommendations, NASA has established career limits for ISS crewmembers' exposure to space radiation. Specifically, the Agency limits individual risk to 3 percent Risk of Exposure-Induced Death (REID) from cancer." I have not been able to track down actual radiation measurements for NASA/Bigelow Expandable Activity Module. On May 26, 2017 NASA stated in "First Year of BEAM Demo Offers Valuable Data on Expandable Habitats". This page is quoted: "...soft materials can perform as well as rigid materials for habitation volumes in space." "BEAM has performed as designed in preventing debris penetration with multiple outer protective layers exceeding space station shielding requirements." I discovered a wealth of space radiation information at the Workshops on Radiation Monitoring for the International Space Station (RMISS). I was delighted that these workshops went beyond just the ISS. Here are some selected reads:
Workshop 9, 2004: "Radiation Measurements and Shielding Analysis for ISS" Go to PROJECTS or EXPLORATION index? |