Space Travel

1. Space Travel

2. Last Night’s Homework 1A. Name three major features of the moon’s surface. Craters, maria, and highlands 1B. How did the moon’s craters form? Meteoroid impacts 1C. Why is the moon’s surface much more heavily cratered than Earth’s surface? Water, wind, and other forces wore away craters on Earth. There is no wind or liquid water on the moon.

3. 2A. Describe the range of temperatures on the moon. 130o C to -180oC 2B. Compare Earth and the moon in terms of size and surface gravity. The moon is one-fourth the diameter of Earth. The moon’s surface gravity is much weaker than Earth’s. 2C. What is the relationship between the moon’s surface gravity, lack of an atmosphere, and temperature range? The moon’s weak surface gravity allows gases to escape into space, so the moon has no atmosphere, resulting in widely varying surface temperatures.

4. 3A. What was the solar system like when the moon formed? It was full of rocky debris. 3B. Explain the various stages in the formation of the moon. A planet-sized object collided with Earth. Material was ejected into orbit around Earth and formed a ring. Gravity caused this material to combine into the moon.

5. Traveling Into Space • Watch the balloon activity that Mrs. Mallay has with a balloon and string. • Is it a rocket?

6. A rocket • A rocket is a device that expels gas in one direction to move in the opposite direction. • A rocket moves forward when gases shooting out the back of the rocket push it in the opposite direction. • This movement demonstrates a basic law of physics: • For every force, or action, there is an equal and opposite force, or reaction.

7. Action and Reaction Forces • The force of the air moving out of our balloon is an action force. • An equal force—the reaction force—pushes the balloon forward. • THRUST is the reaction force that propels a rocket forward • The amount of thrust depends on the mass and speed of the gases propelled out of the rocket • VELOCITY is speed in a given direction.

8. Orbital and Escape Velocity • In order to lift off the ground, a rocket must have more upward thrust than the downward force of gravity • Once a rocket is off the ground, it must reach a certain velocity in order to go into orbit. • ORBITAL VELOCITY is the velocity a rocket must achieve to establish an orbit around Earth. • ESCAPE VELOCITY is the velocity a rocket must reach to fly beyond a planet’s gravitational pull.

9. The main advantage of a multistage rocket is that the total weight of the rocket is greatly reduced as the rocket rises. 4. Second stage separates and falls to Earth. • Second stage ignites and continues with third stage. 2. First stage separates and falls to Earth. A Multi-Stage Rocket 1. Heavy first stage provides thrust for launch

10. The Space Race • The rivalry between the United States and the Soviet Union over the exploration of space was known as the “space race.” • Kennedy’s challenge

11. Space Terms • A satellite is an object that revolves around another object in space. • A space shuttle is a spacecraft that can carry crew into space, return to Earth, and then be reused for the same purpose. • A space stationis a large artificial satellite on which people can live and work for long periods of time. • A space probe is a spacecraft that carries scientific instruments that can collect data, but has no human crew.

12. Homework • Read pages 684 – 691 • Add to your notes • Review notes for next week’s test • Go online and research the “space race” • Do page 691 #1abc and #2ab on loose leaf with a proper heading.