Editing Satellite (section)

==== Low earth orbit satellites ====
Several pollutants are released in the upper atmospheric layers during the orbital lifetime of [[Low Earth orbit|LEO satellites.]] [[Orbital decay]] is caused by atmospheric drag and to keep the satellite in the correct orbit the platform occasionally needs repositioning. To do this nozzle-based systems use a chemical propellant to create thrust. In most cases [[hydrazine]] is the chemical propellant used which then releases [[ammonia]], [[hydrogen]] and [[nitrogen]] as gas into the upper atmosphere.<ref name="Durrieu" /> Also, the environment of the outer atmosphere causes the degradation of exterior materials. The atomic oxygen in the upper atmosphere oxidises hydrocarbon-based polymers like [[Kapton]], [[Teflon]] and [[BoPET|Mylar]] that are used to insulate and protect the satellite which then emits gasses like CO<sub>2</sub> and CO into the atmosphere.<ref>{{cite book |last1=de Groh |first1=Kim |last2=Banks |first2=Bruce |last3=Miller |first3=Sharon |last4=Dever |first4=Joyce |date=2018 |chapter=Degradation of Spacecraft Materials |title=Handbook of Environmental Degradation of Materials |pages=601–645 |edition=Third |doi=10.1016/B978-0-323-52472-8.00029-0 |isbn=978-0-323-52472-8 |hdl-access=free |hdl=2060/20040112017}}</ref>