Space Debris

"Well, here it is," said aerospace engineer William Ailor as he paused next to the hulking metal shells arrayed along the plaza outside a visitor entrance at Aerospace Corp.'s El Segundo, Calif., headquarters.

The stuff is junk. But, Ailor said, it's no ordinary junk. This garbage has traveled to space and back.

A 150-pound hollow sphere of blackened titanium is all that remains of a motor casing from a Delta II rocket that fell to Earth in 2001, landing in the Saudi Arabian desert west of Riyadh.