To get into low Earth orbit—a path in which the forces of motion balance the pull of gravity—a rocket has to attain a speed of about 17,000 miles per hour. To escape the Gravity Well, a vehicle must go about 25,000 miles per hour—33 times the speed of sound. (Daniel Fleisch and Julia Kregenow, A Student’s Guide to the Mathematics of Astronomy)
It really wasn’t that long ago when the two greatest superpowers were vying to put satellites into space. Now, 50 nations have their own satellites in low Earth orbit. If you’re a Thailand, say, you can call Space Systems/Loral, a Canadian-owned company based in Palo Alto, California, and tell them you want to put a satellite into geostationary orbit for television broadcasting or military communications. You can have the thing in orbit 25,000 miles above Earth within two years.
