Introduction Can space workers really make money Well the answer is a big yes Space commerce is a huge business with thousands of companies earning billions of dollars They may launch rockets make artificial satellites and sell the information they supply or build ground stations Satellites provide data for TV radio navigation photos and videos But the future holds more than information only In years to come there could be mining on the Moon or searching deep in space for valuable resources Read on to learn more Crabtree Publishing Company 1-800-387-7650 www.crabtreebooks.com Technicians prepare an early TV satellite for launch in 1962 Since then thousands of satellites have been launched into space
Contents Signals Around the World Assembling a Satellite Websites and Further Information Index and About the Author Aerospace Machines Junkyard in Space Made in Space Observing Earth Finding the Way The Rocketeers 4 6 8 10 12 14 16 18 20 22 24 26 Moon Miners 28 30 31 32 Space Suits Glossary Unlimited Future Robots at the Ready Space Medicine
Signals around the world Making launching and operating artificial satellites is the biggest money-maker in space A communications satellite comsat orbits high above Earth èHow do satellites work A satellite doesn’t work all by itself After construction and inspection a rocket is used to launch it into space Once in orbit the satellite sends and receives electronic signals to and from one or more ground stations A rocket roars off a launch pad on its way to placing a satellite into space How high does a satellite fly Depending on the type of satellite its operating height may be from a minimum of 100 miles 160 km above Earth to as high as 22,000 miles 36,000 km 4
Ground stations receive and send satellite data to billions of users around the world Why do satellites operate at different heights Satellites are built for many purposes Earth observation satellites need to record precise detail for making maps or monitoring weather This purpose is best served by operating in low Earth orbit LEO about 250 miles 400 km above Earth At 22,000 miles 36,000 km above Earth a geostationary Earth orbit GEO satellite appears to stay in one position over the equator This is useful for TV broadcasts because the satellite can reach much of the world at once It also allows you to have a low-cost ground antenna which you can attach to a wall or roof Will we use satellites on other planets In the future local satellite networks will let space explorers and colonists communicate with each other and use computer networks such as the Internet In this 2030s scene Mars explorers stay in touch using nearby satellites The vehicle has a rear-mounted antenna
