Anytime that satellite technology or astronauts are being affected by forms of radiation in space such as fast-moving particles and X-rays, this usually causes some changes to occur. Most of the time these changes are so minor that they have no real consequences either to the way that the satellite operates, or the health of the astronaut. But sometimes, and especially during a severe solar storm or 'space weather event', the conditions in space can change drastically. The term 'space radiation effects' has to do with all of the different ways that these severe conditions can significantly change the way a satellite operates, or the health of an astronaut working and living in space.
When a high-energy particle penetrates a satellites metal skin, its energy can be absorbed by microscopic electrical components in the circuitry of a satellite. The switch can be changed from 'on' to 'off' momentarily, or if the energy is high enough, this can be a permanent change. If that switch is a piece of data in the satellites memory, or a digit in a command or program, it can suddenly cause the satellite to veer out of control until a human operator on the ground can correct this problem. If the particle happens to collide with one of the pixel elements in the satellite's star-tracking camera, a false star might be created and this can confuse the satellite to think it is not pointing in the right direction. Other satellite effects can be even more dramatic. When severe solar storms affect Earth's upper atmosphere, the atmosphere heats up slightly and expands deeper into space. Satellite will feel more friction with the air they are passing through, and this will seriously affect their orbits.
For astronauts, space radiation effects have to do with the amount of radiation (usually x-rays) that pass through the walls of their spacecraft or space station and penetrate into the
body of the astronaut. Most people have an instinctive fear of radiation and its potential biological effects. No matter where you live, you receive a free dose each day of
environmental radiation which adds up to 360 millirems (4- 5 chest X-rays) per
year, and you have no control over this. During the Apollo program, there were several near-misses between the astronauts walking on the surface of the Moon and a deadly solar storm event. The Apollo 12 astronauts walked on the Moon only a few short weeks after a major solar proton flare would have bathed the astronauts in a 100 rem blast of
radiation. Another major flare that occurred half way between the Apollo 16
and Apollo 17 moonwalks would have had a much more deadly outcome had it
arrived while astronauts were outside their spacecraft playing golf. Within a
few minutes, the astronauts would have been killed on the spot with an
incredible 7000 rem blast of radiation. The daily dosage of radiation on the Space Station is about equal to 8 chest X-rays per day.
For more details about these effects, read the accompanying article
Solar Storms and their Human Impacts by Dr. Sten Odenwald (NASA/IMAGE)
