Satellites are human-made objects placed into orbit around Earth or other celestial bodies. They play a vital role in communication, navigation, weather forecasting, Earth observation, and scientific exploration.

• Payload: Instruments or devices that perform the satellite’s primary function (e.g., camera, transponder).
• Bus: The base structure housing essential systems like power, propulsion, and communication.
• Solar Panels: Provide electrical power by converting sunlight.
• Antenna: Enables data transmission to and from Earth.
• Thermal System: Regulates temperature for internal components.

• LEO (Low Earth Orbit): Used for Earth observation, ISS, and many small satellites (500–2000 km).
• MEO (Medium Earth Orbit): Ideal for navigation systems like GPS (around 20,000 km).
• GEO (Geostationary Orbit): Remains fixed over one point on Earth, used for weather and communication satellites (~35,786 km).
• Polar Orbit: Passes over Earth’s poles, offering full planetary coverage—great for mapping and surveillance.

• Communication: TV, internet, phone signals (e.g., GSAT, Starlink).
• Navigation: GPS, GLONASS, Galileo, NavIC.
• Weather Forecasting: Monitoring storms, climate, and rainfall.
• Earth Observation: Agriculture, disaster management, urban planning.
• Science & Space: Space telescopes like Hubble and observatories studying cosmic radiation.

With advancements in miniaturization and reusable rockets, satellite deployment has become faster and more cost-effective, ushering in the era of mega-constellations and global connectivity.