One of the key inventions of the modern world is the geostationary or geosynchronous satellite, many of which are now orbiting the earth today. The fancy term "geostationary" means that the satellite's orbital velocity exactly matches the rotation of the Earth under it. Therefore it remains stationary in the sky, typically orbiting about 22,000 miles above the earth. The first operational geosynchronous satellite (Syncom 2) was launched back in 1963, the year I graduated from high school. 

Many of you can still remember the challenge of the early space flights when the astronauts could only be in contact with the earth when they were directly over a ground station. Such contact would only last a few minutes and in a crisis that got really interesting for both the astronauts and the ground…