Artificial Satellites

A satellite is any object that orbits a planet.

1. Natural satellites occur naturally, like the Moon orbiting Earth.
2. Artificial satellites are manmade machines launched into space to orbit Earth or other planets for specific purposes.

Artificial satellites are human-made objects designed to orbit the Earth or other planets. They serve many purposes, such as communication, weather forecasting, navigation, scientific research, and military surveillance. These satellites carry various instruments to transmit and receive signals and gather data from space.

• The first artificial satellite, Sputnik 1, was launched by the Soviet Union on October 4, 1957.
• Since then, many countries have developed and launched satellites.
• Today, over 3000 active satellites orbit Earth, and thousands more are inactive or considered space junk.

Sputnik

• Satellites use solar panels to generate power from sunlight.
• They carry instruments to collect data and transmit signals to and from Earth.
• Signals are received from ground stations and sent to devices like mobile towers or phones.

Types of Orbits:

1. Geosynchronous Orbit (GSO)

• Completes one orbit in 24 hours, matching Earth’s rotation.
• Stays fixed over the same location on Earth.
• It is used for TV broadcasting and communication.

2, Low Earth Orbit (LEO)

• A few hundred kilometres above Earth.
• It is used for Earth imaging, weather monitoring, and shorter communication systems.

Main Uses of Artificial Satellites:

• Artificial satellites are used for communication, allowing mobile phones, television channels, and internet services to function across the world.
• They help in weather forecasting by monitoring storms, rainfall, and changes in the Earth’s climate.
• Satellites are essential for navigation systems like GPS, which provide accurate location and direction tracking.
• They are used for Earth observation by capturing images to study land use, detect pollution, and monitor natural disasters.
• Satellites support scientific research by helping scientists study planets, stars, and other space-related phenomena.
• They are also used in military operations for surveillance, tracking enemy activities, and ensuring national security.

Communication by artificial satellite 

1. INSAT (Indian National Satellite System) is used for communication, weather forecasting, and meteorology services across India.
2. GSAT (Geosynchronous Satellite) is designed mainly for communication purposes, such as television broadcasting and internet services.
3. IRNSS (Indian Regional Navigation Satellite System) is India’s own navigation system, similar to GPS, that provides accurate positioning within the country and nearby regions.
4. IRS (Indian Remote Sensing Satellite) is used for Earth observation, including mapping, monitoring natural resources, and assessing environmental changes.

Launch Vehicles:

1. GSLV (Geosynchronous Satellite Launch Vehicle) is used to launch heavier satellites into geosynchronous orbit.
2. PSLV (Polar Satellite Launch Vehicle) is used to launch satellites into polar and low Earth orbits and is known for its reliability and cost-effectiveness.

If a manmade object revolves around the earth or any other planet in a fixed orbit it is called an artificial satellite.

• Natural satellites are natural (like the Moon); artificial satellites are manmade and orbit planets.
• Sputnik was the first artificial satellite, launched by the USSR in 1957.
• Satellites use solar panels for energy and send/receive signals.
• Types of satellites: weather, communication, broadcast, navigation, military, and Earth observation.
• India uses INSAT, GSAT, IRNSS, and IRS satellites, launched by GSLV and PSLV rockets.