Space journey —travelling in space

1. 9.5 Space journey —travelling in space Hi!

2. Let’s take a look at the journey in space.

3. Spacecraft in frictionless motion ✘ no air in space no air resistance

4. Spacecraft in frictionless motion in frictionless motion

5. Spacecraft in frictionless motion Space shuttle orbiting the Earth does not need to fire its engine

6. Living in a spacecraft Let’s take a look at our life in space!

7. Weightlessness When a spacecraft is orbiting the Earth … astronauts float around and do not feel their weight weightlessness (無重)

8. Weightlessness That’s why you feel your weight. reaction exerted on you by the ground force exerted on the ground by you

9. Weightlessness Under what conditions can we feel weightless?

10. Weightlessness When the supporting reaction force disappears …

11. Weightlessness Just like when you are on a turbo drop … Wow!

12. Weightlessness Feel weightless separated from the seat; no reaction force to support you both you and your seat fall freely

13. Weightlessness When a spacecraft is orbiting the Earth … astronauts float inside no action force on the spacecraft no reaction force from the spacecraft astronauts feel weightless

14. http://www.universetoday.com/95308/why-are-astronauts-weightless-in-space/http://www.universetoday.com/95308/why-are-astronauts-weightless-in-space/

15. Spacecraft in frictionless motion A spacecraft travelling in space is in frictionless motion.

16. Living in a spacecraft Astronauts feel weightless in space.

17. Daily life inside a spacecraft Foods are individually packaged and precooked.

18. Daily life inside a spacecraft Water is recycled from astronauts’ urine as the supply of water is limited.

19. Daily life inside a spacecraft Astronauts stand by fixing their feet in foot restraints.

20. Daily life inside a spacecraft Astronauts exercise regularly to keep bones and muscles strong.

21. Daily life inside a spacecraft When sleeping, they fix themselves in ‘beds’ to avoid floating around.

22. Daily life inside a spacecraft Astronauts move like divers under weightless conditions.

23. Daily life inside a spacecraft What other problems do astronauts face in space?

24. 9.4 Living in space Match one solution to each of the problems.

25. 9.4 1 In space, there is no air for astronauts to breathe. a The spacecraft are equipped with big solar panels to collect solar energy from the Sun and to change the solar energy to electrical energy.b The spacecraft must be airtight to prevent air from leaking into space. In addition, water is broken down by electricity to produce oxygen.c Astronauts communicate with each other using radio signals.

26. 9.4 2 The spacecraft may not be able to carry enough cells to power all its equipment for its whole journey. a The spacecraft are equipped with big solar panels to collect solar energy from the Sun and to change the solar energy to electrical energy.b The spacecraft must be airtight to prevent air from leaking into space. In addition, water is broken down by electricity to produce oxygen.c Astronauts communicate with each other using radio signals. solar panels

27. 9.4 3 Sound cannot travel in space because there is no air in space. Astronauts working outside the spacecraft cannot talk to each other directly. a The spacecraft are equipped with big solar panels to collect solar energy from the Sun and to change the solar energy to electrical energy.b The spacecraft must be airtight to prevent air from leaking into space. In addition, water is broken down by electricity to produce oxygen.c Astronauts communicate with each other using radio signals.

28. Daily life inside a spacecraft Due to the condition of weightlessness and the limited supply of resources, astronauts have difficulty in doing everyday activities such as eating, drinking and sleeping. Scientists have found ways to solve these problems.

29. Working outside a spacecraft What’s the difference between working on Earth and working in space?

30. Working outside a spacecraft • Problems faced when working outside the spacecraft in space: • no air to breathe • exposed to extreme temperatures and strong radiations • may be hit by tiny meteoroids

31. Working outside a spacecraft Astronauts must wear spacesuits (太空衣) to protect themselves.

32. Working outside a spacecraft How do spacesuits work?

33. Working outside a spacecraft First, let’s learn about some ways heat is transferred.

34. 5 1a Astronauts feel weightless in space because there is no air in space. T F

35. 5 b Astronauts in space exercise regularly to keep their bones and muscles strong. T F

36. 5 c There is no air in space. T F

37. 5 2 State two features of a spacesuit and explain how they protect astronauts when they work outside a spacecraft.

38. 5 2 The visor is coated with a thin layer of gold: it reflects strong sunlight to protect the astronaut’s eyes.

39. Excellent! 5 2 The outermost garment is shiny and white in colour: it reflects heat transferred by radiation to protect the astronaut from the strong direct sunlight. (Accept other reasonable answers.)