Editing Satellite (section)

==Components==
=== Orbit and altitude control ===
{{further|Spacecraft propulsion}}
{{redirect-distinguish|Altitude control|Attitude control}}
[[File:Ion Engine Test Firing - GPN-2000-000482.jpg|thumb|Firing of ''[[Deep Space 1]]''<nowiki/>'s ion thruster]]

Most satellites use chemical or [[ion propulsion]] to [[Orbital maneuver|adjust]] or [[Orbital station-keeping|maintain their orbit]],<ref name=":0" />{{Rp|pages=|page=78}} coupled with [[reaction wheel]]s to control their [[Aircraft principal axes|three axis of rotation]] or attitude. Satellites close to Earth are affected the most by variations in the [[Earth's magnetic field|Earth's magnetic]], [[Gravity of Earth|gravitational field]] and the Sun's [[radiation pressure]]; satellites that are further away are affected more by other bodies' gravitational field by the Moon and the Sun. Satellites utilize ultra-white reflective coatings to prevent damage from UV radiation.<ref>{{cite news |title=Space – American Elements Assists NASA in Development of Ultra White Coating for Satellite Applications |url=https://www.americanelements.com/space-industry.html |url-status=live |archive-url=https://web.archive.org/web/20230406205215/https://www.americanelements.com/space-industry.html |archive-date=6 April 2023 |access-date=2023-04-06 |newspaper=American Elements}}</ref> Without orbit and orientation control, satellites in orbit will not be able to communicate with [[ground station]]s on the Earth.<ref name=":0" />{{Rp|pages=75–76}}

Chemical thrusters on satellites usually use [[monopropellant]] (one-part) or [[bipropellant]] (two-parts) that are [[Hypergolic propellant|hypergolic]]. Hypergolic means able to combust spontaneously when in contact with each other or to a [[Catalysis|catalyst]]. The most commonly used propellant mixtures on satellites are [[hydrazine]]-based monopropellants or [[monomethylhydrazine]]–[[dinitrogen tetroxide]] bipropellants. Ion thrusters on satellites usually are [[Hall-effect thruster]]s, which generate thrust by accelerating [[positive ions]] through a negatively-charged grid. Ion propulsion is more efficient propellant-wise than chemical propulsion but its thrust is very small (around {{Cvt|0.5|N|disp=or|sigfig=1}}), and thus requires a longer burn time. The thrusters usually use [[xenon]] because it is [[Inert gas|inert]], can be easily [[ionized]], has a high [[atomic mass]] and storable as a high-pressure liquid.<ref name=":0" />{{Rp|pages=78–79}}

===Power===
{{Main|Batteries in space|Nuclear power in space|Solar panels on spacecraft}}
[[File:ISS-54 ELC-1, main solar arrays and radiators seen from the Cupola.jpg|alt=see caption|thumb|The [[International Space Station]]'s black solar panels on the left and white [[radiator]]s on the right]]
Most satellites use [[Solar panels on spacecraft|solar panels]] to generate power, and a few in deep space with limited sunlight use [[radioisotope thermoelectric generator]]s. [[Slip ring]]s attach solar panels to the satellite; the slip rings can rotate to be perpendicular with the sunlight and generate the most power. All satellites with a solar panel must also have [[Batteries in space|batteries]], because sunlight is blocked inside the launch vehicle and at night. The most common types of batteries for satellites are [[Lithium-ion battery|lithium-ion]], and in the past [[Nickel-hydrogen batteries|nickel–hydrogen]].<ref name=":0" />{{Rp|pages=88–89}}