1. Chapter 2
Technological developments are making space exploration possible and offer benefits on Earth.

2. 2.1 Technologies for Space Transport
The greatest challenges in space travel have been:
achieving escape velocity to break free of Earth’s gravitational force
designing materials and equipment able to withstand the extreme environment of space
transporting people out and back safely

3. Satellite technology is used for many Earth-based applications, including:
telecommunications
navigation
remote sensing, and
weather forecasting.
Satellites, unmanned space probes, and manned spacecraft need a velocity of about km/h (11 km/s) to escape Earth’s gravity!

4. The Achievements of Rocket Science
Early experiments in rocket propulsion included:
- Archytas’ steam-powered pigeon (Ancient Greece)
- gunpowder arrows for warfare (China 1st C AD)
- Robert Goddard’s liquid fuel rockets (1920s)
- Wernher von Braun’s V2 rockets (1940s)
- Sputnik I, first artificial satellite (Oct. 4, 1957)
- Sputnik II, with Laika, the first space traveler (1957)

5. The father of modern rocketry is considered to be Robert Goddard
The father of modern rocketry is considered to be Robert Goddard. Along with Konstantin Tsiolkovsky of Russia and Hermann Oberth of Germany, Goddard envisioned the exploration of space. Goddard was a physicist with a unique genius for invention.
By 1926, Goddard had constructed and successfully tested the first liquid-fuel rocket with a rocket flight on March 16,1926, at Auburn, Massachusetts.

6. Wernher von Braun was one of the first and foremost rocket engineers, and a leading authority on space travel. His will to expand knowledge through the exploration of space led to the development of the Explorer satellites, the Saturn rockets, and Skylab (the world's first space station). In addition, his determination led to humans landing on the moon.
The V2 rocket was developed during World War II using a fuel of alcohol and oxygen.

7. The Apollo 17 capsule making a parachute landing in the ocean in December 1972

8. Rocket Basics Three Parts:
1) mechanical elements (currently about 3% of the rocket mass)
- rocket, engines, storage tanks, fins
2) payload (currently about 6% of rocket mass)
- crew cabins, crew, food, water, air, etc.
3) fuel (currently about 91% of rocket mass)

9. Rockets

10. Future Propulsion Technologies
Finding alternatives to liquid or gas burning fuels would decrease our reliance on inefficient fossil fuels and the mass problems associated with storing and transporting all that fuel.
Possible alternatives for the future include:
1) ion drives (using electrically-charged xenon gas)
2) solar sails (using carbon-fibre sails to absorb photons)

11. Ion Drives Are engines that use xenon gas instead of chemical fuels.
Are engines that use xenon gas instead of chemical fuels.
In the space craft engine, the xenon is electrically charged, accelerated, and then emitted as gas.
This action pushes the spacecraft in the direction opposite to the emission

12. Solar Sails
Instead of using air currents, solar sails use the Sun’s light.
The Sun emits electromagnetic energy in the form of photons.
The photons hit the sail and the energy transmitted causes the spacecraft to move

13. Shuttles, Probes & Space Stations
The International Space Station (ISS) is a modularized permanent laboratory that will also serve as a base for building and launching rockets for interplanetary travel.
What are the advantages and disadvantages of building and launching spacecraft from Earth orbit or the Moon?

14. Space Craft
The International Space Station (ISS) is a modularized permanent laboratory that will also serve as a base for building and launching rockets for interplanetary travel.
There are three main types of spacecraft in use. Shuttles transport personnel and equipment to orbiting spacecraft.
Space probes contain instrumentation for carrying out robotic exploration of space.
Space stations are orbiting spacecraft that have living quarters, work areas, and all the support system needed to allow people to live and work in space for extended periods.

15. http://www. dailymail. co

16. Sounds of Earth recording carried by Voyager
Image of Saturn by Voyager 2, 1981
The Voyager I and 2 space probes were launched in 1977

17. International Space Station
Canadarm2

18. Check & Reflect
p. 417 (1-9)

19. 2.2 Living in Space The hazards of space consist of:
no air (near vacuum) or air pressure
no water
cosmic rays
solar radiation (esp. solar flares)
debris and objects in space
temperature extremes
psychological stress due to confinement and isolation
physical stress due to lack of gravity and exercise combined with extended time in space

20. Gravity
Gravity is the force of attraction between masses. On Earth, gravity gives us our feeling of weight.
Microgravity is the condition in which the gravitational forces that act on mass are greatly reduced.
For example, a person would weigh only 1/3 on Mars then what they would weigh on Earth.
This is because on Mars, the force of gravity is weaker than on Earth. In space, the person is almost completely weightless.

22. Space Suit Technology
Suits must be designed to mimic an Earth environment capable of sustaining human life for periods long enough to work outside a spacecraft or space station.
What features must be built into a suit?
1) Air Tight, Provides it’s own atmosphere
2) Gloves and flexibility to complete tasks.
3) Water for drinking and a system for waste.
4) Helmet with visor to protect your Eyes from radiation
5) Communication system
6) Back up systems for all life supporting functions

24. Apollo 17 commander Eugene A
Apollo 17 commander Eugene A. Cernan in spacesuit removing equipment from a Lunar Roving Vehicle during training.

25. Space Station Technology
Essential features include:
clean water (electrolysis + recycling nearly 100%)
breathable air (removing CO2, microorganisms, dust and moisture)
suitable temperature and air pressure
a source of power

26. Life Support Systems
Recycling is essential in the day-to-day life in the space station.
Since there is little room for storage, as much as the materials carried as possible must be recyclable or re-useable.
On the International Space Station, life support systems are designed to ensure life.

27. Life Support Systems The functions of the life support system include:
Recycling wastewater to produce drinking water
Using recycled water to produce oxygen
Removing carbon dioxide from the air
Filtering micro-organisms and dust from the air
Keeping air pressure, temperature and humidity stable

29. Producing Oxygen
The process of electrolysis uses electricity to split water molecules into their component elements: hydrogen and oxygen.
In a spacecraft, this process can supply most of the oxygen the crew needs. The hydrogen is vented into space.

30. Check & Reflect
p. 425 (1-5)

31. 2.3 Meeting Human Needs on Earth
How do satellites transmit and receive information from the ground?
Data is relayed using radio waves.
Some satellites, such as those used in weather forecasting, are placed in geosynchronous orbit, which means the satellite moves so it is over the same Earth location at all times.
Other satellites, such as RADARSAT and LANDSAT, monitor global activities such as shipping, soil, fires and potential resources. They are not placed in geosynchronous orbits for these reasons.

32. Satellites Satellites are sometimes referred to as
“artificial satellites” – these are objects that are built
and sent into Earth’s orbit by humans.
A Natural satellite refers to any small body that
orbits a larger body such as a moon orbiting a planet.
Satellites help us communicate, observe and forecast weather, predict magnetic storms, and even find our location on the planet.
Satellites can orbit in Low, Medium or Geosynchronous (High) Earth Orbit

33. Low Earth Orbit Earth observation satellites and spy
satellites use LEO as they are able to
see the surface of the Earth more
clearly as they are not so far away.
They are also able to traverse the
surface of the Earth.
The International Space Station is in a LEO about 400 km above the Earth's surface.
It takes about 92 minutes for the ISS to orbit around Earth.

34. Geosynchronous Earth Orbit
Geosynchronous orbit (GEO) is a
circular orbit 35,786 km above the
Earth and follows the direction of
the Earth's rotation. 
To ground observers it appears motionless, at a fixed position in the sky.
Communications satellites and weather satellites are often placed in geostationary orbits, so that the satellite antennas (located on earth) which communicate with them do not have to rotate to track them, but can be pointed permanently at the position in the sky where the satellites are located. 

35. Remote Sensing Satellites can monitor changes in: global temperature
soil and vegetation patterns
the atmosphere
industry and urbanization.
• In addition, remote sensing can locate mineral and fuel resources hidden undersea and underground.

37. Global Positioning Systems (GPS)
What minimum number of satellites would it take to pinpoint the compass position of an object on the surface?

38. GPS
GPS was designed to give people, wherever they are, their location on the ground at any time.
24 GPS satellites are in orbit around Earth. At least three are above any given location in the world at any given moment.
Radio signals from the satellites are picked up by a hand-held receiver.
The signals are translated by a computer in the receiver, which then shows on a digital display the operator’s position in relation to the satellites.

39. Space Age Systems & Materials
Examples:
Computer: virtual reality software
Consumer: improved bike helmets
Medicine: digital imaging for detecting cancers
Industrial: micro-lasers for cutting and melting
Transportation: improved traction on winter tires
Public Safety: emergency response robots

40. Check & Reflect
p. 432 (1-7)
Chapter 1 and 2 Quiz
Tuesday January 26