1. Topic 6 Space Exploration
Above the Atmosphere and Under Control
Topic 6
Space Exploration

2. Rockets – Getting Up There
A tube that contains combustible material in one end and a payload in the other end and moves by the action, reaction principle
Payload:
The device or material that a rocket carries

3. Rockets – Getting Up There
As the fuel in the rocket combusts it produces exhaust from the rocket
The exhaust pushes the rocket in the opposite direction
This is called the action / reaction principle

4. Rocket Fuel Exhaust Velocity:
The speed at which exhaust leaves a rocket
All rockets require a type of fuel in order to operate
Rocket fuel used to be solid (ex. Gun powder), however this type of fuel has very low exhaust velocity

5. Rocket Fuel Robert Goddard: American Physics professor
First scientist to successfully launch a liquid fuel rocket in 1926
He also knew that if a rocket had more than one stage it would fly faster and higher

6. Rocket Fuel Staged Rocket: A rocket with more than one stage
A stage is a section of a rocket that drops of once its fuel is used up

7. The V-2 Rocket Werner von Braun: German Scientist
During World War 2 he created the world’s first ballistic missile called the V-2 rocket and launched it in 1942
The V-2 rocket was a liquid fuel rocket
The V-2 Rocket successfully hit a target about 200 km away
Now, almost every rocket is a variation on this design
Dr. Wernher von Braun

8. The V-2 Rocket Ballistic Missile:
A rocket with a bomb as a payload, launched in a trajectory that sends it up into space and down onto its target Ballistic Missile Test

9. The V-2 Rocket
Near the end of WWII the Americans and Russians both wanted to capture von Braun and his team
The Americans were successful and his team helped create the U.S. Space Program

10. The V-2 Rocket
Von Braun’s team built the rockets that took the first U.S. astronauts into space in the 1960’s
After WWII the Russians were able to design the Vostok, Voshkod and Soyuz rockets that sent their Russian Cosmonauts into orbit
Cosmonaut:
The Russian term for astronaut

11. Computers – Making Adjustments
Computers were invented in WWII and were the size of entire rooms
These first computers were used to decipher enemy code 

12. Computers – Making Adjustments
In the 1960’s, computers were required to keep rockets in orbit around the earth but had to be used on the ground as they were too big
Now, computers are small enough to fit on the spacecraft and are used to calculate orbits, keep track of other satellites, collect, store, and analyze data, and execute orbital manoeuvres of the satellites.

13. Using Gravity Gravitational Assist:
A method of acceleration which enables spacecraft to change speed by using the gravity of a planet
This technique is used because spacecraft are too heavy to send on long journeys throughout the solar system

14. Using Gravity Steps of Gravitational Assist
As the spacecraft comes near to a planet it is attracted to it by its gravitational pull
As the spacecraft begins to orbit the planet it speeds up
The spacecraft will then leave the orbit moving faster than it was before it entered
This gives the spacecraft enough speed to travel to more distant celestial objects

15. Clarifying Images Charge Coupled Devices (CCD’s):
Devices that convert light signals into electric signals in digital format
The images are then sent to a computer
This allows images of distant objects to be altered in order to become more clear and detailed

16. Aiming the Hubble Telescope
The Hubble telescope (named after the famous astronomer Edwin Hubble) is the size of a bus with a main mirror diameter of 2.4 m
In April of 1990 it was sent into Earth’s orbit using a rocket

17. Aiming the Hubble Telescope
It is controlled by an on- board computer system
The Hubble telescope is a fantastic viewing tool as it contains spectrometers and cameras that are able to see distant objects without interference from Earth’s atmosphere

18. Looking at Earth
An example of a naturally occurring satellite is the Moon (or the Earth if you really think about it!)
However, humans have sent many artificial satellites into the Earth’s orbit.

19. Looking at Earth Artificial Satellite:
A satellite made by humans, such as a spacecraft or telescope.
These artificial satellites carry instrumentation (including computers) and their own power source (usually solar panels) Sputnik

20. Looking at Earth Artificial Satellite cont’d:
Artificial satellites are required for the following Earthly reasons:
Communications
Observation
Monitoring
Navigation
Mapping
Real World: Mission to Mercury

21. Communication Satellites
The world is now a “Global Village” because of instant communications
These communications are made possible by orbiting satellites
There are two types of communications satellites:
Low Earth Orbit satellites
Geosynchronous Orbit satellites.

22. Communication Satellites
Low Earth Orbit Satellites:
Placed km high above the Earth
They complete one orbit of Earth in roughly 1.5 h.
These satellites circle Earth faster than Earth rotates

23. Communication Satellites
Low Earth Orbit Satellites cont’d:
When seen from the ground, these satellites move across the sky in a matter of minutes
Moving antennae track their signals
These types of satellites are often used for telephone signals as they are close enough to the Earth to eliminate lag time in phone conversation

24. Communication Satellites
Geosynchronous Orbit Satellites:
Placed km above Earth directly above the equator
Move in the same direction as Earth rotates
Take 24 h to orbit the Earth once (ie. they are synchronized with Earth’s rotation)

25. Communication Satellites
Geosynchronous Orbit Satellites cont’d:
When seen from the ground, these satellites appear stationary in the night’s sky
Stationary antennae track their signals
These types of satellites are often used for television as they allow for a continuous signal

26. Observation and Monitoring Satellites
Observation and Monitoring Satellites are used for forecasting weather, carrying our research and helping ships, aircraft, and other vehicles determine their exact location on Earth
Ex. The satellites used to create the images for “Google Earth”

27. Remote Sensing Remote Sensing:
Taking measurements of Earth (and other planets) from space
Remote sensing is used for the following:
Can show healthy vs. unhealthy regions of vegetation on the Earth
Clear-cut and burned forests can be mapped to show the rates of their degradation
Water pollution can be imaged
Erosion can be tracked
Land use in cities can be observed
Weather can be tracked

28. Global Positioning System (GPS)
Using a fleet of GPs satellites above Earth and small hand-held GPS units on Earth, you can calculate your position on Earth to within 30 m (military units can be accurate to within a few centimetres!!!!!)

29. Global Positioning System (GPS)
GPS Satellites:
NAVSTAR (Navigation Satellite Tracking and Ranging) is a group of satellites that were placed km above the Earth’s surface by the U.S. military
These satellites take about 12 h to complete one orbit
There are enough GPS satellites in orbit so that there are always at least three above the horizon, wherever you are in the world, whatever time of the day!!!!

30. Global Positioning System (GPS)
GPS Satellites cont’d:
The satellites send out radio signals that are detected by the hand-held GPS units
The distance is calculated based on the time that it took for the signal to be detected (like sonar or ultrasound)
The hand-held unit then calculate your location on Earth using triangulation

31. Global Positioning System (GPS)
GPS Satellites cont’d:
GPS was originally designed for military use but is now used for:
Fishing
Airplanes
Palaeontology
Golf
Etc.