LAUNCH DATES: Perhaps the first person to come up with the concept of an artificial earth satellite was Sir Isaac Newton. In 1687, he pointed out that if he shot a cannonball from a mountaintop with sufficient velocity, it would circle the world before falling. Since no one could think of a reason to do such a thing, that was pretty much the last word on the subject for centuries. Then, in October 1945, a young radar instructor and aspiring writer named Arthur C. Clarke laid the ground rules for satellite communications in an article published in Wireless World. At the time, most folks considered Clarke's vision of orbiting manned stations in outer space more science fiction than science. Only 12 years later, however, Russia launched the world's first artificial satellite, Sputnik I -- a 58-cm aluminum ball that sent home a steady beep simply to let the world know the Russians got to space first. Not to be outdone, the Americans followed a few months later with Explorer I, which was two metres long and weighed approximately 14 kg. The space race was on.
NORTHERN FLIGHTS: On September 29,1962, Canada became the third nation to have a satellite in space. Alouette 1 cost $3 million and weighed 146 kg. Its mission: to study the ionosphere (the electrically charged upper atmosphere). Flying 1,000 km above the earth, Alouette 1 operated for a decade before being deactivated (though it remains in orbit). With the launch of the $15-million Anik Al in 1972, we became the first country to operate a commercial domestic-communications satellite system. In 1976, a new satellite, Hermes, a joint project of the Department of Communications and NASA, brought us coast-to-coast TV broadcasts. In all, Canada has sent 21 satellites into space - the most recent being Anik Fl (pictured here, at right), which weighs 4,700 kg and went up last year. Its price tag: over $400 million. Its mission: to carry television, telephone and Internet signals throughout the Americas. There have been 12 Anik satellites. Satellites are only one segment of our surprisingly large space industry, which last year employed more than 5,500 people at some 250 firms and brought in revenues of $1.2 billion, with exports amounting to 45% of sales.
RISE AND FALL: About 5,000 satellites have been put into space by 40 countries and seven multinational organizations. Of these, 2,700 or so remain aloft and working. Until recently, only about 10% of the sats launched each year were commercial models. By 1996, that figure had risen to 45%. Why? Two reasons: the telecommunications revolution, which by 2007 will see the launch of 270 to 350 new commercial sats; and the collapse of Russia. Since 1997, it has reduced by 80% per year the number of military sats it puts up. What's more, one analyst believes that 70% of Russia's 100 to 130 military satellites are nearing the end of their operational life, prompting fears that, says one expert, the country will no longer have access to "reliable space-based sensors" that can assure leaders they are not under attack when other systems mistakenly suggest otherwise.
UNDER THE HOOD: The typical satellite is made up of: a flight computer; a processor to control data flowing in and out of the computer; an omni antenna to transmit messages between the satellite and ground control; a high-gain antenna to send large amounts of data; digital cameras to record the Earth's surface; image sensors to process and transmit the pictures; wing solar panels to generate electricity; a battery to store the solar power; star trackers to aid navigation; and reaction wheels to point the satellite in different directions. All these parts are placed on the "bus," a strong, lightweight structure usually made of titanium or aluminum that's wrapped in a glittering foil thermal blanket that protects the delicate electronics from extraterrestrial temperatures ranging from -156 to 121 degrees Celsius.
WHAT GOES UP: Since 1957, man has put more than 26,000 objects into orbit. The U.S. Space Command in Colorado tracks about 9,000 of them. The space junk up there includes dead satellites, pieces of spent rockets, lens caps, paint chips, etc. When man-made space debris tumbles earthward, it usually disintegrates through atmospheric friction - but more junk makes it to the ground than you'd suspect. For example, on January 22,1997, a 264-kg stainless-steel tank from a Delta II rocket second stage missed landing on a house in Texas by a mere 45 metres, and later the same day Lottie Williams of Tulsa, Okia., was hit on the shoulder by a 15-cm piece of charred-metal mesh from the same rocket while walking in the park. Fortunately, she was unhurt. Others may not be so lucky. There are still about 90 Delta I and Delta II rocket second stages floating in space and computer models show that every one should survive reentry. (Check out http://fuse.pha.jhu.edu/users/reentry.html for pictures of junk that fell to earth.)