Earth will be pummeled by old satellite portions
The Upper Atmosphere Research Satellite has been revolving about the world for the last two decades. The satellite arrived at what NASA called “the end of a productive scientific life” a full six years back. By Saturday, UARS is expected to come falling back to Earth. Resource for this article:
How UARS has lived
Orbit has had the Upper Atmosphere Research Satellite around for a while started in 1991. The ozone layer was to be studied with the satellite. It was supposed to study other aspects of the Earth’s atmosphere too. The UARS was intended to last around three years at first. UARS had 60 percent of instruments still working after 14 years, but National Aeronautics and Space Administration decided shutting it down was the best option. UARS is about the size of a bus and is covered mostly in gold foil-like material.
National Aeronautics and Space Administration talks re-entry
National Aeronautics and Space Administration explained that the satellite is a “heavily decaying orbit.” Between September 22 and 24, the UARS is expected to get back into the Earth’s atmosphere. Most of the satellite is expected to break up in the atmosphere and burn up, but up to 100 separate pieces won’t melt away entirely. Some of the parts will be as heavy as 300 pounds. NASA believes that UARS probably will not hit ground. There’s a 1 in 3,200 chance any piece will hit the ground. Antarctica is the only continent that does not have to worry. The chance that each individual piece will hit an individual is about 1 in 20 trillion.
The UARS satellite status will be updated every two hours by National Aeronautics and Space Administration. Even with that, the best estimate is that National Aeronautics and Space Administration will be able to provide two hours’ warning on the UARS re-entry. UARS is falling fast. This is due to the solar activity going on. The communication satellite issues are also blamed on the activity. Though UARS is falling from the sky easily, it is just one of the estimated 22,000 portions of “space junk” revolving about the earth.
NASA.gov: (PDF) http://www.nasa.gov/pdf/585584main_UARS_Status.pdf
LA Times: http://latimesblogs.latimes.com/nationnow/2011/09/space-junk-expert-on-why-nasa-needs-to-clean-up-space.html