Topic 6 – Above the Atmosphere and Under Control

Darn Atmosphere The atmosphere prevents us from getting a clear picture of objects in space. BOO ATMOSPHERE There are ways of getting around this……

Rockets! A rocket is a tube that contains combustible materials in one end. On the other end of the rocket is the materials or device that the rocket carries – this is called the payload. What sorts of things would a rocket carry?

Rocket Fuel Rockets NEED a combustible fuel to make them fly Fuels create exhaust The speed the exhaust leaves the rocket is called the exhaust velocity This determines the rockets range – how high and how far

Rockets, before 1926, were launched with solid fuel. Gun powder Robert Goddard successfully launched a rocket with liquid fuel in 1926.

Staged Rocket A staged rocket is one that once launched will drop a section of the rocket once the fuel is used up. The rocket flies in stages. Why would it want to drop part of the rocket?

V-2 Rockets - Werner von Braun and WWII The V-2 Rocket Werner von Braun was a German scientist during WWII He experimented with liquid fuel rockets to help Nazi war efforts The worlds FIRST ballistic missile (a bomb powered by a rocket engine) was launched in 1942 This rocket successfully hit a target 200km away These kinds of rockets were then fired at Great Britain V-2 Rockets - Werner von Braun and WWII

End of WWII Near the end of WWII, the American’s and Russian’s wanted what von Braun had created. The American’s got von Braun to go to American to work on the rockets The developed the rocket to take the first U.S. astronauts into space in 1960. Werner von Braun and space exploration

No pilot? If there is no pilot how do they control where the rocket goes?

Gravitational Assist Gravitational assist is a method used to accelerate a spacecraft to gain extra speed by using the gravity of a planet. SLINGSHOT

Rockets and Computers The Hubble Space Telescope In 1990, the space shuttle Discovery blasted off with Hubble on board. The telescope is the size of a bus Computers on Earth communicate with Hubble to tell it where to go and what to do.

Satellites Artificial satellites are ones that we make – telescopes, space crafts Some of these even look down on Earth to tell us mapping (google Earth), communication, etc. Natural satellites are things like the moon, or even Earth.

Communication Satellites We are able to: watch sports events from all over the world get news (like the Japan disaster) phone anyone in the world BECAUSE OF COMMUNICATION SATELLITES!

Some communication satellites are placed in low Earth orbit and others in geosynchronous orbit Low Earth Orbits are placed 200-800 km high Complete one orbit of Earth in 1.5 hours Geosynchronous Orbits are placed 36,000 km high. Complete one orbit of Earth in 24 hours.

Geosynchronous satellites Because these satellites are so far away they appear to stay in one spot in the sky. These are good for TV stations and satellite T.V. If a television satellite were not always visible in the sky we would not get all of the programs we want

Low Earth Orbit Telephone satellites are used in low Earth orbit because there is a quick transfer between people who are talking If these satellites were further away there would be a lag in the conversation

Remote Sensing Remote sensing is the science of taking measurements of Earth from space Healthy and unhealthy vegetation Clear-cut and burned forests Water pollution Erosion Land use in cities Weather

Global Positioning System (GPS) U.S military placed GPS satellites (called NAVSTAR) for tracking GPS satellites are about 20,000 km above Earth and there are so many of them currently that there is always one within our view

Each GPS unit contains a receiver and a computer. The unit detects radio signals and measures the distances to each satellite by comparing how long it takes for the signals to be received. It uses triangulation to tell you where you are within 30m.