Role and History of satellites

1. Satellite Communication

2. Group Members
• Talha Khan (13083122-025)
• Mubashar Husain Shah (13083122-026)
• Ali Hasnain (13083122-028)
• Jamal Shams Khanzada (13083122-035)

3. What is a Satellite?
• A Satellite is a manufactured object that orbits Earth or something
else in space on a continual basis. Artificial satellites are used to study
the universe, help forecast the weather, transfer telephone calls and
assist in ship and aircraft navigation.

4. What is Communication?
• Exchange of information via speaking, writing or any other medium.
Communication can be of any type, it may b through text SMS or
letter or a telephone call or 3G video call or an image.

5. What is satellite Communication?
• 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.

6. What is transponder?
• In a communications satellite, a transponder gathers signals over a
range of uplink frequencies and re-transmits them on a different set
of downlink frequencies to receivers on Earth, often without changing
the content of the received signal or signals

7. World’s First Satellite
• In 1957, the world was surprised to see the
Soviets launch the first satellite into orbit, with
most expecting the USA to be the first to do so.
The satellite, named “Sputnik 1”, transmitted a
simple radio signal back to earth for 21 days and
remained in orbit for a further 6 months.

8. Sputnik

9. World 2nd Satellite
Sputnik 2 was the second
spacecraft launched into
Earth orbit, on 3
November 1957, and the
first to carry a living
animal, a dog named
Laika.

10. World’s first spacecraft
The Vostok was a type of
spacecraft built by the
Soviet Union. The first
human spaceflight in
history was accomplished
on this spacecraft on
April 12, 1961, by Soviet
cosmonaut Yuri Gagarin.

12. Parts of a Satellite
1) Command Antenna
2) Communication Antenna
3) Solar Cells
4) Batteries
5) Radio Receivers and transmitters
6) Rocket Fuel
7) Main pocket Motor
8) Rocket Thrusters

13. Principle
• The fundamental principle to be understood concerning satellites is
that a satellite is a projectile. That is to say, a satellite is an object
upon which the only force is gravity. Newton was first to theorize it.
One launched in space, the only force acting on it is the force of
gravity that continuously pulls it towards earth but as after very
8000m the along the horizon, earth curves downward by 5m.

14. What is the size of Communication Satellite?
• Size varies. Communication satellites can be as big as a small school
bus and weigh up to 6 tons, the Federal Communications Commission
says. Most weigh a few tons or less. Some that are used briefly are 4
inch cubes and weigh about 2 pounds.*
*http://talkingpointsmemo.com/idealab/satellites-earth-orbit

15. Where are Communication Satellites
• Communications satellites relay signals from a fixed spot on the
equator, about 22,000 miles up. GPS satellites are at 12,400 miles,
high enough to be accessible to large swaths of the Earth. Others that
need a closer look at Earth are lower. For comparison, the
International Space Station is only about 260 miles high, and very few
satellites are lower than that.

16. Number of Communication Satellites
Country
Number of
Satellites
U.S.A 502
Russia
118
China 116
Thailand 04
Total
Satellites
3700
Working 1100
Not Working 2600
About 1017 satellites provide civilian communication and about 792 military
communication

17. Satellites of Pakistan
• Pakistan sent his first (and internationally 1153rd) satellite in space
named “Paksat 1” later it was replaced with “Paksat 1R” on 11 August
2011. It is working on a downlink frequency of 3700-4200MHz and
uplink frequency of 5925-6425MHz.

18. Future Works
• Now the solar cells used in the satellite are upgrading by upgrading
the material used in making cell. Further good and long lasting
batteries are being used. We are using thermal maps in future.

19. Thank You