This document discusses different types of orbits for satellites: low Earth orbit (LEO), medium Earth orbit (MEO), and geosynchronous Earth orbit (GEO). LEO is below 1000 km from Earth's surface and allows satellites to circle Earth every 90 minutes. GEO is much farther at 35,786 km, allowing satellites to match Earth's rotation and remain stationary over one position. MEO ranges between LEO and GEO and is commonly used for navigation satellites like Europe's Galileo system.

1. 6th
CLASS
Course Name : Data Communication
Course Code : CSE 313
Topics
Satellite
Rakibul Hasan Emon, ID : 1915002532, Department of CSE, City University
Satellite :
A satellite is a moon, planet or machine that orbits a planet or star. For example,
Earth is a satellite because it orbits the sun. Likewise, the moon is a satellite
because it orbits Earth. Usually, the word "satellite" refers to a machine that is
launched into space and moves around Earth or another body in space.Earth and
the moon are examples of natural satellites.
On 4 October 1957, the Soviet Union launched the world's first artificial
satellite, Sputnik 1.
BRAC Onnesha was the first nanosatellite built in Bangladesh to be launched into
space. The satellite was designed and built in conjunction with Kyushu Institute of
Technology Birds-1 program, which has the goal of helping countries build their
first satellite. It was designed and built over a two-year period.

2. The Bangabandhu Satellite-1 (Bangabandhu-1) is the first Bangladeshi
geostationary communications and broadcasting satellite. It is located at an
altitude of 35,786 km above the ground.
There Are Three Types Of Satellite :
1. Low Earth Orbit (LEO)
2. Medium Earth Orbit (MEO)
3. Geostationary Orbit (GEO)
Low Earth Orbit (LEO) :
A low Earth orbit (LEO) is, as the name suggests, an orbit that is relatively close to
Earth’s surface. It is normally at an altitude of less than 1000 km but could be as
low as 160 km above Earth – which is low compared to other orbits, but still very
far above Earth’s surface. By comparison, most commercial aeroplanes do not fly
at altitudes much greater than approximately 14 km, so even the lowest LEO is
more than ten times higher than that. Satellites in this orbit travel at a speed of
around 7.8 km per second; at this speed, a satellite takes approximately 90
minutes to circle Earth, meaning the International Space Station(ISS) travels
around Earth about 16 times a day.

3. Geosynchronous Earth Orbit (GEO) :
Satellites in geostationary orbit (GEO) circle Earth above the equator from west to
east following Earth’s rotation – taking 23 hours 56 minutes and 4 seconds – by
travelling at exactly the same rate as Earth. This makes satellites in GEO appear to
be ‘stationary’ over a fixed position. In order to perfectly match Earth’s rotation,
the speed of GEO satellites should be about 3 km per second at an altitude of 35
786 km. This is much farther from Earth’s surface compared to many satellites.
Medium Earth Orbit (MEO) :
Medium Earth orbit comprises a wide range of orbits anywhere between LEO and
GEO. It is similar to LEO in that it also does not need to take specific paths around
Earth, and it is used by a variety of satellites with many different applications.It is
very commonly used by navigation satellites, like the European Galileo system
(pictured). Galileo powers navigation communications across Europe, and is used
for many types of navigation, from tracking large jumbo jets to getting directions
to your smartphone.
Reference :
https://www.nasa.gov
https://en.wikipedia.org
https://www.esa.int