space environment and its challenges 1000
Answers
The environment plays a significant role to support life on earth. But there are some issues that are causing damages to life and the ecosystem of the earth. It is related to the not only environment but with everyone that lives on the planet. Besides, its main source is pollution, global warming, greenhouse gas, and many others. The everyday activities of human are constantly degrading the quality of the environment which ultimately results in the loss of survival condition from the earth
Source of Environment Issue
There are hundreds of issue that causing damage to the environment. But in this, we are going to discuss the main causes of environmental issues because they are very dangerous to life and the ecosystem.
Pollution – It is one of the main causes of an environmental issue because it poisons the air, water, soil, and noise. As we know that in the past few decades the numbers of industries have rapidly increased. Moreover, these industries discharge their untreated waste into the water bodies, on soil, and in air. Most of these wastes contain harmful and poisonous materials that spread very easily because of the movement of water bodies and wind.
Greenhouse Gases – These are the gases which are responsible for the increase in the temperature of the earth surface. This gases directly relates to air pollution because of the pollution produced by the vehicle and factories which contains a toxic chemical that harms the life and environment of earth.
Climate Changes – Due to environmental issue the climate is changing rapidly and things like smog, acid rains are getting common. Also, the number of natural calamities is also increasing and almost every year there is flood, famine, drought, landslides, earthquakes, and many more calamities are increasing.
Answer:
The Harsh Environmental Conditions of a Spacecraft and the Hazards Posed to the Electronics
The first hurdle for space electronics to overcome is the vibration imposed by the launch vehicle. The demands placed on a rocket and its payload during launch are severe. Rocket launchers generate extreme noise and vibration. There are literally thousands of things that can go wrong and result in a ball of flame. When a satellite separates from the rocket in space, large shocks occur in the satellite’s body structure. Pyrotechnic shock is the dynamic structural shock that occurs when an explosion occurs on a structure. Pyroshock is the response of the structure to high frequency, high magnitude stress waves that propagate throughout the structure as a result of an explosive charge, like the ones used in a satellite ejection or the separation of two stages of a multistage rocket. Pyroshock exposure can damage circuit boards, short electrical components, or cause all sorts of other issues. Understanding the launch environment provides a greater appreciation for the shock and vibration requirements, and inspections imposed on electronic components designed for use in space level applications.
Outgassing is another major concern. Plastics, glues, and adhesives can and do outgas. Vapor coming off of plastic devices can deposit material on optical devices, thereby degrading their performance. For instance, an automobile plastic dashboard can emit vapor that deposits a film on the windshield. This is a practical example I can attest to from personal experience. Using ceramic rather than plastic components eliminates this problem in electronics. Outgassing of volatile silicones in low Earth orbit (LEO) cause a cloud of contaminants around the spacecraft. Contamination from outgassing, venting, leaks, and thruster firing can degrade and modify the external surfaces of the spacecraft.
High levels of contamination on surfaces can contribute to electrostatic discharge. Satellites are vulnerable to charging and discharging. For that reason, space applications require components with no floating metal. Satellite charging is a variation in the electrostatic potential of a satellite, with respect to the surrounding low density plasma around the satellite. The extent of the charging depends on the design of the satellite and the orbit. The two primary mechanisms responsible for charging are plasma bombardment and photoelectric effects. Discharges as high as 20,000 V have been known to occur on satellites in geosynchronous orbits. If protective design measures are not taken, electrostatic discharge, a buildup of energy from the space environment, can damage the devices. A design solution used in geosynchronous Earth orbit (GEO) is to coat all the outside surfaces of the satellite with a conducting material. The atmosphere in LEO is comprised of about 96% atomic oxygen. Oxygen exists in different forms. The oxygen that we breathe is O2. O3 occurs in Earth’s upper atmosphere, and O (one atom) is atomic oxygen. Atomic oxygen can react with organic materials on spacecraft exteriors and gradually damage them. Material erosion by atomic oxygen was noted on NASA’s first space shuttle missions, where the presence of atomic oxygen caused problems. Space shuttle materials looked frosty because they were actually being eroded and textured by the presence of atomic oxygen. NASA addressed this problem by developing a thin film coating that is immune to the reaction with atomic oxygen. Plastics are considerably sensitive to atomic oxygen and ionizing radiation. Coatings resistant to atomic oxygen are a common protection method for plastics. Another obstacle is the very high temperature fluctuations encountered by a spacecraft. A satellite orbiting around Earth can be divided into two phases; a sunlit phase and an eclipse phase. In the sunlit phase, the satellite is heated by the Sun and as the satellite moves around the back side or shadow side of the Earth, the temperature can change by as much as 300°C. Because it is closer to the Sun, the temperature fluctuations on a satellite in GEO stationary orbit will be much greater than the temperature variations on a satellite in LEO.
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