2. Pyramids at Giza

3. Early Space Explorers Aristotle 384-322 Ptolemy 85-165 Copernicus 1473-1543 Brahe 1546-16011564-1642 GalileoKepler 1571-1630 Newton 1642-1727

4. Aristotle 384-322 Early Space Explorers

5. Aristotle Aristotle Laws of Motion The natural state of objects is at rest The natural state of objects is at rest Heavy objects fall faster than light objects Heavy objects fall faster than light objects

6. Early Space Explorers Aristotle Aristotle Earth = center of universe Earth = center of universe Moon, Sun & 5 known planets carried on crystalline spheres Moon, Sun & 5 known planets carried on crystalline spheres Orbit are circular Orbit are circular Superluner vs. Sublunar Superluner vs. Sublunar

10. Ptolemy 85-165 Early Space Explorers

11. Ptolemy Ptolemy Earth = center of universe Earth = center of universe Moon, Sun & 5 known planets carried on crystalline spheres Moon, Sun & 5 known planets carried on crystalline spheres Orbit are circular Orbit are circular Epicycles, eccentrics, equants added to describe motion Epicycles, eccentrics, equants added to describe motion EpicycleEquant The Ptolemaic Solution Eccentric

12. Early Space Explorers Ptolemy Ptolemy Earth = center of universe Earth = center of universe Moon, Sun & 5 known planets carried on crystalline spheres Moon, Sun & 5 known planets carried on crystalline spheres Orbit are circular Orbit are circular The Ptolemaic Solution

13. Dark Ages The models developed by Aristotle and Ptolemy dominated astronomy for 14 centuries

14. Copernicus 1473-1543 Early Space Explorers

15. Copernicus Copernicus Sun is near the center of universe Sun is near the center of universe Planets rotate around Sun on crystalline spheres Planets rotate around Sun on crystalline spheres Orbit are circular Orbit are circular Simpler explanation for path of planets Simpler explanation for path of planets Interior Planet Exterior Planet

16. Early Space Explorers Brahe 1546-1601

17. Early Space Explorers Brahe Brahe Earth = center of universe Earth = center of universe Sun and Moon rotate around Earth Sun and Moon rotate around Earth All other planets rotate around the Sun All other planets rotate around the Sun Very precise measurements of the heavens using a sextant Very precise measurements of the heavens using a sextant

18. Early Space Explorers Brahe Brahe h = 2 D tan (½ ) D  h 22 22

19. Early Space Explorers Kepler 1571-1630

20. Early Space Explorers Kepler Kepler Sun = center of universe Sun = center of universe Planets rotate around the Sun in elliptical orbits Planets rotate around the Sun in elliptical orbits 3 Laws 3 Laws Kepler’s First Law The orbits of the planets are ellipses with the Sun at one of the foci

21. Early Space Explorers Kepler Kepler Sun = center of universe Sun = center of universe Planets rotate around the Sun in elliptical orbits Planets rotate around the Sun in elliptical orbits 3 Laws 3 Laws Kepler’s Second Law The line between an orbiting planet and the Sun sweeps out equal areas in equal times

22. Early Space Explorers Kepler Kepler Sun = center of universe Sun = center of universe Planets rotate around the Sun in elliptical orbits Planets rotate around the Sun in elliptical orbits 3 Laws 3 Laws Kepler’s Third Law The square of an orbit’s period is proportional to the cube of the average distance between the planet and the Sun P 2 ~ a 3

23. Early Space Explorers Kepler Kepler

24. Early Space Explorers 1564-1642 Galileo

25. Early Space Explorers Galileo Galileo Invented the telescope Invented the telescope Moon: mountains, valleys Moon: mountains, valleys Sun: blemishes Sun: blemishes

26. Early Space Explorers Galileo Galileo Invented the telescope Invented the telescope Disproved Aristotle Disproved Aristotle Moon: mountains, valleysMoon: mountains, valleys Sun: blemishesSun: blemishes Light and heavy objects fall at the same rate Light and heavy objects fall at the same rate

27. Early Space Explorers Newton 1642-1727

28. Early Space Explorers Newton Newton Miracle Year – 1665: Miracle Year – 1665: Invented calculusInvented calculus Law of GravitationLaw of Gravitation First reflective telescopeFirst reflective telescope 1667: Mathematical Principles of Natural Philosophy 1667: Mathematical Principles of Natural Philosophy  Newton’s Laws of Motion 1. “Every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed upon it” 2. “Force is equal to the change in mometum per change in time” 3. “For every action, there is an equal and opposite reaction”

29. Konstantin Tsiolkovsky “Father of Russian Cosmonautics” 1857-1935 His Classic article "Research into Interplanetary Space by Means of Rocket Power" was published in 1903, the year of the first airplane flight by the Wright Brothers. It accurately described the state of weightlessness and the theoretical function of rockets in a vacuum. He demonstrated why rockets would be needed for space exploration, and also advocated the use of liquid propellants that are used today.

30. Robert Goddard “Father of Modern Rocketry” 1882-1945 His experiments with both solid and liquid fueled rockets formed much of the basis of the development of ballistic missiles, earth-orbiting satellites, and interplanetary exploration.

31. Wernher Von Braun 1912 - 1977 Braun began working on a new secret weapon, the V2 Rocket. This 45 feet long, liquid-fuelled rocket carried a one ton warhead, and was capable of supersonic speed and could fly at an altitude of over 50 miles. V2 RocketV2 Rocket 5,000 V-2s were launched, only 1,100 hit their target. In 1952, Braun became technical director of the US Army's Ballistic Missile Agency at Huntsville, Alabama and was chiefly responsible for the manufacture and successful launching of Redstone, Jupiter-C, Juno and Pershing missiles.