Satellites Fall from the Sky
The sky wasn't really falling in autumn 2011; it just seemed that way, with two defunct satellites plummeting to Earth out of control within a month of each other.
First came NASA's Upper Atmosphere Research Satellite, or UARS. This 6.5-ton climate satellite, which was about the size of a school bus, launched in 1991 and was decommissioned in 2005. UARS then spent six years spiraling slowly toward our planet, finally plunging into the atmosphere above the Pacific Ocean on Sept. 24.
Germany's 2.7-ton Roentgen Satellite, or ROSAT, followed closely on UARS' heels. This craft, which launched in 1990 to survey the heavens in X-rays and was shut down in 1999, fell back to Earth over the Indian Ocean on Oct. 23.
Neither uncontrolled satellite crash injured anyone. But the sky isn't done raining down huge pieces of space junk. Russia's failed Mars probe Phobos-Grunt will plummet to Earth by January 2012.