Learn about various artificial satellites such as military and civilian, Earth observation satellites, communications satellites, navigation satellites, weather satellites, and research satellites. Also learn about Space stations and human spacecraft in orbit.

1. Types of Artificial Satellites

2. Artificial Satellites
Types of Artificial
Satellites
In the context of spaceflight, a satellite is an artificial object which has
been intentionally placed into orbit. Such objects are sometimes called
artificial satellites to distinguish them from natural satellites such as
Earth's Moon.
Artificial satellites are used to study the Earth, other planets, to help us
communicate, and even to observe the distant Universe. Satellites can
even have people in them, like the International Space Station and the
Space Shuttle. Satellites are used for a large number of purposes.
Common types include military and civilian Earth observation satellites,
communications satellites, navigation satellites, weather satellites, and
research satellites. Space stations and human spacecraft in orbit are also
satellites. Satellite orbits vary greatly, depending on the purpose of the
satellite, and are classified in a number of ways.

3. Astronomical Satellites
Types of Artificial
Satellites
Astronomical satellites are satellites used for observation of distant planets, galaxies, and
other outer space objects. An astronomy satellite is basically a really big telescope floating
in space. Because it is in orbit above the Earth, the satellite's vision is not clouded by the
gases that make up the Earth's atmosphere, and its infrared imaging equipment is not
confused by the heat of the Earth.

4. Weather Satellites
Types of Artificial
Satellites
Weather satellites are primarily used to monitor Earth's weather and climate. Meteorological satellites
see more than clouds and cloud systems. City lights, fires, effects of pollution, auroras, sand and dust
storms, snow cover, ice mapping, boundaries of ocean currents, energy flows, etc., and other types of
environmental information are collected using weather satellites. Other environmental satellites can
detect changes in the Earth's vegetation, sea state, ocean color, and ice fields.

5. Biosatellites
Types of Artificial
Satellites
Biosatellites are satellites designed to carry living organisms, generally for scientific experimentation.
Biosatellites are designed to study the biological effects of weightlessness (i.e., zero gravity), cosmic
radiation, and the absence of the Earth’s 24-hour day-night rhythm on several plants and animals
ranging from a variety of microorganisms to a primate. Such space laboratories were equipped with
telemetering equipment with which to monitor the condition of the specimens.

6. Communications Satellites
Types of Artificial
Satellites
Communications satellites are satellites stationed in space for the purpose of telecommunications.
Modern communications satellites typically use geosynchronous orbits, Molniya orbits or Low Earth
orbits. A communications satellite is an artificial satellite that relays and amplifies radio
telecommunications signals via a transponder; it creates a communication channel between a source
transmitter and a receiver at different locations on Earth.

7. Earth Observation
Satellites
Types of Artificial
Satellites
Earth observation satellites are satellites intended for non-military uses such as
environmental monitoring, meteorology, map making etc. They are specifically
designed for Earth observation from orbit.

8. Navigational
Satellites
Types of Artificial
Satellites
Navigational satellites are satellites which use radio time signals transmitted to enable
mobile receivers on the ground to determine their exact location. The relatively clear line
of sight between the satellites and receivers on the ground, combined with ever-improving
electronics, allows satellite navigation systems to measure location to accuracies on the
order of a few meters in real time. Navigation satellites are designed expressly to aid the
navigation of sea and air traffic.

9. Crewed Spacecraft
Types of Artificial
Satellites
Crewed spacecraft (spaceships) are large satellites able to put humans into (and beyond) an orbit, and
return them to Earth. Spacecraft including spaceplanes of reusable systems have major propulsion or
landing facilities. They can be used as transport to and from the orbital stations. Spacecraft carrying
people may be operated directly, by human crew, or it may be either remotely operated from ground
stations on Earth or be autonomous, able to carry out a specific mission with no human involvement.

10. Reconnaissance
Satellites
Types of Artificial
Satellites
Reconnaissance satellites are Earth observation satellite or communications satellite
deployed for military or intelligence applications. Very little is known about the full power
of these satellites, as governments who operate them usually keep information pertaining
to their reconnaissance satellites classified.

11. Space Stations
Types of Artificial
Satellites
Space stations are artificial orbital structures that are designed for human beings to live on in outer
space. A space station is distinguished from other crewed spacecraft by its lack of major propulsion or
landing facilities. Space stations are designed for medium-term living in orbit, for periods of weeks,
months, or even years. Today's space stations are research platforms, used to study the effects of
long-term space flight on the human body as well as to provide platforms for greater number and
length of scientific studies than available on other space vehicles.

12. Tether Satellites
Types of Artificial
Satellites
Tether satellites are satellites which are connected to another satellite by a thin cable called a tether.
Tether satellites can be used for various purposes, including research into tether propulsion, tidal
stabilization and orbital plasma dynamics. Space tethers are long cables which can be used for
propulsion, momentum exchange, stabilization and altitude control, or maintaining the relative
positions of the components of a large dispersed satellite/spacecraft sensor system.

13. Killer Satellites
Types of Artificial
Satellites
"Killer Satellites" are satellites that are designed to destroy enemy warheads,
satellites, and other space assets. Anti-satellite weapons (ASAT) are Space weapons
designed to incapacitate or destroy satellites for strategic military purposes.

14. Recovery Satellites
Types of Artificial
Satellites
Recovery satellites are satellites that provide a recovery of reconnaissance,
biological, space-production and other payloads from orbit to Earth.

15. This presentation is a result of my experiences while I was
helping out my son with his school assignments and project
work. I am happy to share this with other students and their
parents. Hope you find this informative and useful. Thank you.
- Prashant Mahajan -
All pictures belong to their original authors, photographers.