Traveling in outer space sounds fun. Being an astronaut seems to be an exciting career. Until the gringa is reminded about space radiation. Those heavy duty marshmallow looking suits astronauts wear are not just to keep them warm, properly pressurized and surrounded by oxygen. They also protect against dangerous space radiation. But is it enough? Are spacecrafts and the International Space Station adequately protected or are our astronauts slowly being radiated to death?
Radiation is an invisible energy form of high-speed particles and electromagnetics. It surrounds humans in everyday artificial light, sunlight, and electronics that produce radio-, television-, and micro- waves. Radiation comes in two forms:
- Ionized: This is the worst in the form of gamma rays, protons and neutrons. Exposure to ionized radiation results in exposed atoms becoming unstable by an energy powerful enough to remove electrons from their orbit around the atom’s nucleus.
- Non-ionized: Not powerful enough to destabilize atoms, this is the kind of common radiation produced by microwaves, radio waves and light.
The radiation in space is, unfortunately, comprised of ionized radiation. There are three things that typically create dangerous space radiation:
- Trapped radiation: The Earth’s core creates a magnetic field that surrounds our planet up to several thousand kilometers from our planet’s surface. Solar wind carries charged particles that slam into our magnetic shield. Some particles manage to pass through. Those that don’t create a shockwave that deflects from Earth’s magnetic field. This creates layers of cavities called the “magnetosphere” that act as shock absorbers to protect Earth further from charged particle bombardment. But some particles get trapped in these cavities and they become radioactive belts surrounding Earth. Astronauts have to pass through these dangerous belts before they reach deeper space.
- Galactic Cosmic Radiation (GCR): Outside our solar system ionized atoms traveling at almost light speed pass through space matter, including humans and man-made objects unless they are properly shielded.
- Solar Particle Events (SPE): Sometimes the Sun flares and ejects copious amounts of highly charged radioactive particles into space. These particles travel so fast they are capable of reaching Earth within ten minutes of a solar or coronal flare event. These are dramatic happenings that temporarily drastically increase radiation exposure.
Astronauts traveling through space radiation or living in the ISS have to be protected from space radiation. Radiation exposure causes damage to human cells. There is a scientific formula used to calculate how much radiation exposure an astronaut can expect when working on the ISS. It’s a bit too complicated for the gringa to understand. These calculations are the reason ISS missions have a maximum six month cycle and spacewalks are limited. Exposure is increased during a spacewalk to perform repairs and maintenance.
Shielding is preferred to be constructed of materials like polyethylene because it has a high hydrogen content. This kind of material is more effective than metals at reducing the ability of particles to pass through and enter the modules. Astronauts also wear monitors called “dosimeters” that constantly measure the level of radiation damage to the chromosomes in their blood cells.
Every single astronaut is a hero. No matter what the duration of their mission. No matter what the nature of their mission. No matter what it is they did, whether it seemed glamorous or insignificant, these men and women are heroes of science. They are risking their lives every moment they are off the surface of the Earth. Even if they return safely, they have still sacrificed much. From musculo-skeletal issues to organ damage and higher cancer risks, every single astronaut will experience the effects of radiation exposure for a lifetime despite the measures taken to protect them. If you ever meet an astronaut thank them for their invaluable sacrifice and service performing critical scientific endeavors that are helping us understand our origins, learn about climate change conditions and create solutions to save our homeworld.
Image source: antarcticglaciers.org