This month's AE presenter: James Aubuchon
Date of presentation: May 2019 (exact date uncertain)
Subject: How to Build a Space System II, the Space Environment Proper
Description: Space is by its nature a difficult environment in which to place and operate any kind of system. The space environment is characterized by high vacuum, temperature extremes, thermal cycling, and low gravity.
Though a small speck can damage a satellite, over 500,000 pieces of orbital debris larger than 10 cm are currently tracked by NASA. There are over 40 known meteor showers that pass through Earth’s upper atmosphere. There are also cosmic rays, micrometeoroids, and other particulates. The chemical environment includes very reactive atomic oxygen and the Van Allen radiation belts. There is an induced environment as the result of venting and outgassing from the space system itself which can interact with the space system.
Space weather variations, due mainly to the Sun, make the environment more challenging. While visible light is approximately constant, X-ray and ultraviolet light are highly variable in time and space.
Solar wind, solar flares, coronal mass ejections, solar energetic particles, x-ray flares, solar radio bursts, & solar proton events are unpredictable and are sometimes huge to monumental. These can react directly with the space system or with the Earth’s magnetosphere to cause geomagnetic storms. They can energize the ionosphere and the Van Allen radiation belts.
Direct effects on the space system may include radiation damage which can cause single event upset, latchup, loss of orientation, execution of phantom commands, and degradation of solar panels. They may result in spacecraft charging with subsequent spark discharge and possible damage. Effects on the atmosphere may result in scintillation of satellite to ground communication.
These are some of the factors which make space a difficult environment. Taken individually, any one might prove hazardous to endurance, navigation, or general operation of a space system. Taken collectively, they make operating any such system in space a massive and yet delicate undertaking.
