2.  Why should humans explore the space?  Is it possible for humans to explore places beyond the solar system?  Will we ever reach other stars?  What are the obstacles that we should overcome before we can make explorations to far places like other galaxies?

3. Voyage to Proxima Centauri  Proxima Centauri, the closest star to us aside from the sun is 4.2 light years away.  It means that even if you travel at the speed of light, it will still take you approximately 8 years and 5 months to make a round trip journey to this neighboring star

4. First Step Into Space  Space Voyages are made possible by the combined use of rocket, radios and computers

5. Rockets  Are self-propelled devices that carry their own fuel, as well as the oxygen, or other chemical agent, needed to burn fuel.  Fire Arrow, rockets by the Chinese were used as weapons as early as 1232. A fast-burning mixture similar to gunpowder was used as fuel.

6. How Can Rockets Fly?  Rockets are based on Isaac Newtons Third Law of Motion (also called the law of action-reaction)  This law states that “for every action there is always an opposite and equal reaction”

7. How Can Rockets Fly?  The fuel container and burning chamber of a rocket is a tube that has nozzle at one end.

8. How Can Rockets Fly?  When the fuel burns, the expanding gases exert an action force on every inner part of the tube.

9. How Can Rockets Fly?  The tube pushes back with a force on all surfaces except the nozzle where the hot gases escape.

10. How Can Rockets Fly?  A thrust force builds up at the end of the nozzle.

11. How Can Rockets Fly?  Thrust is the force that propels the rocket forward.

12. How Can rockets Fly?  On Earth’s surface, a large amount of force is needed to overcome gravity and friction

13. How Can Rockets Fly?  In space, less thrust is needed to move a rocket forward.

14. The Space Age  Began in 1967 when USSR used a rocket to launch Sputnik I into Earth’s orbit

15. The Space Age  Signals from two radio transmitters on Sputnik I were heard around the world.

16. The Space Age  Sputnik I was an artificial satellite

17. What is a Satellite?  It is an object that revolves around a larger body  We have natural satellites such as the moons  We have the artificial satellites like the Sputnik I

18. Artificial Satellite  Are used for communications and for monitoring weather.

19. Echo  The first reflector communications satellite

20.  On its surface it had a thin aluminum coating that acted like a mirror to reflect light and radio waves Echo

21.  Was used to relay telegrams, telephone calls and pictures across continents and oceans.  Television images were also relayed by this satellite. Echo