Earth, like the larger planets, has a complex system of rings. Being blessed with intelligent life (or at least, complex, tool-using life), Earth didnt need natural processes to create those ornaments: Earths rings are man-made litter. Legacy software, especially the vast installed base of DOS-era code thats been carried along to Windows 9x, reminds me of those rings around the Earth. We were too shortsighted to do things neatly the first time, and we pay the price 10 or 100 times over with each successive generation of attempted improvements.
We have to build new space systems to survive in a shooting gallery that contains more than 100,000 objects at least one centimeter across—with typical collision speeds of 10 kilometers per second. Imagine a .45-caliber bullet coming at you with 40 times the muzzle velocity of the formerly standard Marine Corps semiautomatic pistol—and, remember, impact energy goes with speed squared.
The International Space Station, recently improved by the addition of the $1.4 billion Destiny lab module, "will be the most heavily shielded spacecraft ever flown," according to NASA Johnson Space Center documents. I hope so; of those centimeter-plus objects that might try to perforate the space stations hull, about 8 percent are at least the size of a regulation softball. Ouch!
We cant simply decide to place future satellites above the 2,000-kilometer altitude that encloses most space junk; its almost as hard to leave behind the old, creaky drivers and other code that inspire even Microsoft to deprecate Windows 9x as an unreliable platform.
We can, however, look at the costs of protecting future IT projects from the space junk of previous efforts; we can choose to consider those "shielding" costs when we evaluate higher-| altitude IT options.