1. Travel to Space

2. Rockets
reaction
Newton’s Third Law – for every action there is an equal and opposite reaction
rocket gas is under pressure in a tank
when gas is released in a combustion reaction it produces a downward thrust
then the rocket lifts upward and away from Earth in an opposite reaction
rockets must reach an escape velocity of km/h to overcome Earth’s gravitational pull
action

3. there are 3 basic parts to a rocket
the structural and mechanical parts (engines, storage spaces, tanks, fins)
fuel (can be various materials such as liquid oxygen, gasoline or liquid hydrogen
payload – what is being transported by the rocket (people, food, water, air, cargo)
what are possible payloads (what types of things are being transported by rockets)
Fins – are important because they stablilize the rocket (so it does not wobble) and make it more efficient
designed in stages so empty fuel tanks can be dropped when the fuel is used up… this makes rockets more efficient

4. Technologies for Space Travel (theoretical propulsion systems)
Ion drives
engines that use xenon gas instead of chemical fuel
xenon is electrically charged in the engine, accelerated, then emitted as exhaust
exhaust creates thrust which pushes spacecraft in opposite direction
Solar Sails similar to wind pushing sailboats
solar sails collect electromagnetic energy from the Sun… when ‘photons’ hit the sail they transfer energy which causes the spacecraft to move forward
Gravitational Assist
fly a spacecraft toward a planet or star, then at the last minute pull around it and away… creating a slingshot effect that shoots the craft forward in the desired direction

5. Space Craft space shuttles are used to transport people into space
space probes are used for ‘non-manned’ exploration of space – they carry instruments for recording info
e.g. Pioneer 11 – flyby of Jupiter and Saturn in
e.g. Mars Pathfinder – landed on Mars in 2000
space stations are orbiting space craft that have living quarters, work areas, support systems… to allow for people to live and work in space for extended periods of time

6. Satellites and Probes natural satellites such as the moon
man-made satellites such as used for communication
Communication satellites – “wireless” technologies
Observation and research satellites – weather, tracking systems (e.g. radar)
Remote sensing – imaging of earth surface
Global Positioning Systems

7. Satellite Orbits Low Earth Orbit Geosynchronous Orbits
200 – 1000 km altitude
e.g. remote sensing satellites
Geosynchronous Orbits
medium or high Earth orbit
satellite moves at the same rate as the Earth… so it records the same area of the Earth at all times
e.g. weather satellites
Geostationary Orbits
satellite stays in one place while the Earth moves… so it records a different area of the Earth over time
e.g. communication satellites

8. Hazards of Space Travel
Launch hazards – combustion of fuel and escape of Earth’s gravity are risky
Cosmic and solar radiation – medically hazardous for human health
Collisions – natural hazards and man made (space junk)
Re-entry into an atmosphere – risk of burning up due to friction of Earth’s atmosphere on craft
Fuel expenditure – running out of fuel

9. Living in Space Sustainable food and water supply
need sophisticated wastewater recycling capabilities to produce drinking water
food provides high energy for low volume and weight
Environmental setting
steady temperature, pressure & humidity
passing electricity through water to produce oxygen

10. Waste management Safety removing carbon dioxide from air
filtering micro-organisms and dust from air
handling biological waste and garbage
Safety
space is a vacuum – no air or water
detection for fire, leaks, incoming risks like meteorites
protection from radiation and cold
systems to handle emergencies like a fire or loss of pressure/air

11. Water Recycling System – International Space Station
SIA – page 422

12. Movement outside habitat requires:
space suit
supply of oxygen
water supply (& food)
temperature control
waste management
carbon dioxide
body waste
communications
attachment (to space craft)

13. Physical and Psychological Risks
microgravity – lower gravity
produces lower stress on our bodies
can result in loss of muscle mass, expansion of bones, weakening of heart
visual depth perception is affected
confined living - isolation
limited space
limited companions
no fresh air

14. Telescopes Optical telescopes → light collectors
use a series of lenses or mirrors to collect and focus light & images from space
larger lens = more visibility
operate in the visible light spectrum
first developed in 1608 by Hans Lippershey… but it was Galileo who is credited with using telescopes to study the night sky

15. Reflecting Telescope Refracting Telescope
2 lenses gather and focus light
disadvantage is that the lens will warp if diameter > 1 m
Refracting Telescope
uses mirrors to gather and focus the light

16. Radio Telescope resemble a large satellite dish gather radio waves
advantage over optical telescopes, because they are not affected by weather, clouds, atmosphere or pollution
have greatly expanded our knowledge of our solar system and galaxy

17. Interferometry
combining 2 or more optical OR radio telescopes to detect objects with better clarity at greater distances

18. Telescopes in Space
telescopes located in space have a better view because there is no atmosphere to distort the images
Hubble Space Telescope
orbits 600 km above the Earth
reflecting telescope
launched in 1990

19. Electromagnetic Spectrum
Optical Telescopes operate within narrow band of visible light waves
Radio Telescopes operate within wider band of radio waves

20. Useful Inventions from Space Exploration
SIA, page 431