![[TESS.png]] TESS (Transiting Exoplanet Survey Satellite) - NASA ## About Satellites are multi-purpose. You can do a lot with them. - Planet observation. - Earth observation. - Communications. - Weather tracking. - GPS - Military. - Research. ## Components ### Sensors Magnetometers - Checks the strength and direction of Earth's magnetic field to get it's orientation https://satsearch.co/products/aac-clyde-mag-3-satellite-magnetometer Gyroscopes - Measures the rotational velocity to identify the satellite orientation over time. https://satsearch.co/products/tensortech-cmg-10m-control-moment-gyroscope Star trackers - Captures images of stars and compares against a star map to get it's positioning information. https://satsearch.co/products/redwirespace-star-tracker ## Orbit To be familiar with the mechanics, we have to understand the distances. - Low Earth Orbit (LEO) - 160 to 2,000 KM. - Medium Earth Orbit (MEO) - 2,000 to 35, 768 KM. - Geostationary Orbit (GEO) - 35,768 KM - This matches Earth's rotation velocity so you can have a fixed spot. - High Earth Orbit (HEO) - 35,768 KM + ![[Orbit.png]] (Wikipedia) ## Orbital Perturbations Additional gravitational influences and forces that affect the primary orbit by inducing small periodic changes - GRAVITATIONAL - Influence from other massive bodies (Sun or Moon) - Atmospheric drag - Friction from the atmosphere leading to orbital decay (altitude loss) - Solar radiation pressure - Photons from the Sun exerting a small force on the satellite ## Tracking