Since the 1960s, humanity's forays into space have become so commonplace that no one really notices launches anymore. Oh, people pay attention to NASA's space shuttle, but, really, can you remember the last time a communications payload was put into orbit?
I think this is good, in a way. Using space for the benefit of humanity has become necessary in many respects. But, with so many launches of so many satellites (not to mention the shuttle missions and those association with the International Space Station), litter has tended to build up over the past few decades.
Space litter. Junk left over from previous launches and missions and spacewalks and what-have-you. On the ground, such mission detritus would pose no real problems because whoever came along next could just kick the debris to the side of the road.
In space, however, the junk remains in orbit, which means it is moving around the earth at very high speeds. If such trash would happen to hit a valuable item -- such as the space shuttle -- then severe damage could result.
Enter the 1st Space Control Squadron. This unit of Peterson Air Force Base is located in Cheyenne Mountain Air Force Station in Colorado. There, they keep an eye on all identifiable manmade items in orbit and assess the danger they may pose to any current or future space mission. Not a very celebrated unit of the Air Force, I am sure, but an absolutely necessary one.
Keep watching the skies, guys.