Apollo 8 The Apollo 8 astronauts circling the moon in 1968 were the first people to view earth from afar. Since that historic mission, many images of earth have been taken, showing how small and fragile earth seems in the vastness of the universe.

The Use of Space Since 1957, when Sputnik I was sent into space, scientists have been using human- made satellites as important tools in space. Orbiting earth, these objects are now used by many countries from all over the world for communication, observation and monitoring, navigating, and mapping.

Communication Satellites In 1953, Queen Elizabeth’s Coronation was filmed and then rushed over to North America by plane for Canadians to see. Nowadays we are able to watch the World Cup Soccer AS IT HAPPENS!! The world has become a global village of instant communication, thanks to orbiting satellites.

Satellites orbiting close to earth take about.5 hours to circle the planet. A moving antenna is needed to track them. Geosynchronous satellites are in synchronized orbit with the earth’s rotation – so it makes one complete orbit each time the earth rotates and appears to be motionless over a point on the earth’s surface.

Canada is a world leader in the development and use of communication satellites. On November 10, 1972, Canada’s domestic communication satellite, Anik 1, was launched from Cape Canaveral. On February 5, 1973, the Canadian Broadcasting Corporation started network television transmission to Canadians – the first country in the world to use satellites to transmit television! More sophisticated Anik satellites have been launched since then.

Observation Satellites Observation satellites are used for forecasting weather, carrying out research, and helping ships, aircrafts, and other vehicles determine their exact location on earth. Satellites can also be used to measure depths of snow, the extent of ice build-up in arctic waters, and the locations of forest fires.

Forest Fires on the California Coast

Some observation satellites use spectroscopy to measure air pollution. Hot gases emit specific colours of light and cold gases absorb those colours, a satellite can analyze light patterns in the atmosphere to determine how abundant a particular gas is.

Canadian observation satellites are named LANDSAT and RADARSAT. The center for remote sensing in Ottawa maintains two receiving stations for the satellites – one in Prince Albert, SK. and one Gatrineau, Quebec.

Global Positioning System Satellites (GPS) A small, hand held GPS unit uses satellite technology to find where you are on earth. More than two dozen GPS satellites, called NAVSTAR (for navigation and satellite tracking and ranging) are now spread out in high orbit around the earth so wherever you are, there are at least three above the horizon.

Photographing Space Satellites can aim their instruments outward from earth and take images far out into space. Orbiting above earth’s atmosphere means that the satellite is not affected by the atmosphere, which distorts transmission, and as a result, the pictures taken are much more clear.

Space Travel For generations, people have dreamed of travelling to distant parts of the universe. In 1969, when Neil Armstrong stepped onto the moon’s surface from Apollo 13, the event marked a major milestone in achieving the dream. Robotically-operated space probes have landed on Venus and Mars and have given close up views of the ground on these foreign worlds.

For several years, the US sent astronauts to Sky Lab, a small space station orbiting earth. Space Stations have living quarters, work and exercise areas, and all of the equipment and support systems that humans require to live and work in space. In the 1980’s and 1990’s, Russian astronauts lived in the space Station Mir for extended periods of time.

Space Stations Sky Lab Mir

For the last decade, the Space Shuttle has also been carrying astronauts and scientists into orbit. A major component of the Space Shuttle is the robotic arm outside the spacecraft that can be manipulated by remote control. The arm was developed by a Canadian company – Spar Aerospace. Shuttle crews have used the arm to release and retrieve satellites from the Shuttle’s cargo bay, as well as a rescue mission when the Hubble Telescope was found to be defective after the launch!

The next major space project is the International Space Station – a joint project between the US, Canada, most of Europe, Russia, and Japan. The Space Station will be a permanent lab where scientists can conduct long-term research experiments in space. It also might become the site of spacecraft construction and launching.

Careers Involving Space Exploration Space exploration is an exciting field for many reasons. It requires the application of nearly all areas of science and technology to the goal of discovery and learning. It also involves an adventurous spirit and a great deal of resourcefulness and imagination. It is an area of human endeavor where international cooperation and exchange is vital if advances are to be made.

Astronaut The ultimate space-related career is being one of the individuals to travel beyond the earth’s atmosphere. Astronauts must be in peak physical condition to perform demanding tasks required in the small quarters of a space craft. Periodically, the Canadian Space Agency advertises for applicants to train for this job.

Satellite Technologist Constructing satellites or developing software to manage the satellites and interpret data, there are many links between computer technology and satellite communication. Engineers, physicists, mathematicians, chemists, mechanics, computer programmers, and technicians are all members of the satellite teams.

Aerospace Industry Careers Architects and trades people in several countries are working on modules of the International Space Station – everything from sleeping quarters to inventing recipes for occupants, Workers in the aerospace industry design and build the spacecrafts that explore the solar system and the rockets that lift them off the earth.

Astronomer Many major universities have an astronomy department. Astronomers are hired to teach the subject and carry out research. Many Canadian universities have excellent astronomical telescopes, and Canadian astronomers share observation time on the world’s great optical and radio telescopes.

Careers in Microgravity Research Astronauts living and working in space must cope with the effects of microgravity, which is a condition in which objects in orbit seem to be weightless. In reality, gravity is acting on them, but its effects are reduced. Human living in a microgravity environment for prolonged periods of time develop health problems: bones and muscles weaken. If we ever want to launch extended trips – to mars maybe, then we need to learn the effects of microgravity on the human body.

Challenges of Space Travel A feeling of weightlessness (page 420) Health and other risks (page 421) Space Junk (page 424)