Space Exploration

• A planet:

  • orbits a star
  • does not emit light
• An exoplanet is a planet that orbits a star that is not our sun
• A dwarf planet:

  • orbits a star
  • is not large enough or spherical enough to be a planet
• Asteroids are:

  • lumps of rock that orbit a star
  • smaller than a dwarf planet
• A moon:

  • orbits a planet
  • is a natural satellite
  • reflects light
• A star:

  • is a massive ball of hot gas
  • emits light and all parts of the EM spectrum
• A solar system is the planets, moons and asteroids which orbit a star
• A galaxy is a group of stars and solar systems
• The universe is all space, matter and time
• Satellites can be used for:

  • GPS
  • weather forecasting
  • telecommunications
  • space exploration
• A geostationary satellite stays at the same place above earth all the time
• A geostationary satellite has a period of 24 hours
• A geostationary satellite orbits the earth at a height of 36000m
• As orbital height increase, the period of a satellite increases
• challenges of space travel are:

  • travelling large distances
  • manoeuvring spacecraft in a zero friction environment
  • maintaining sufficient energy to operate life support systems on a spacecraft
• Travelling large distances can be overcome by:

  • using ion drive to provide a small unbalanced force over a long distance
  • using a catapult from a small, fast moving asteriod
• Maintaining sufficient energy to operate life support systems in a space craft can be overcome by using solar cells
• Risks associated with manned space exploration include:

  • fuel load on take-off
  • potential exposure to radiation
  • Pressure differential in space
  • Re-entry through atmosphere
• The forces acting on a rocket at take-off are:

  • Engine force
  • weight
  • air resistance
• The action and reaction forces acting on a rocket during take-off are:

  • rocket pushing hot gas downwards
  • hot gasses push rocket upwards
• order of planets is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
• The basic needs for humans are:

  • food
  • oxygen
  • water
  • shelter
  • warmth