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UARS Re-Entry
A decommissioned NASA science satellite is falling back to Earth. The Upper Atmosphere Research Satellite, or UARS, will re-enter the atmosphere late Friday, Sept. 23, or early Saturday, Sept. 24, Eastern Daylight Time. The satellite’s rate of descent has slowed since Thursday, meaning re-entry could happen several hours later than originally predicted.

 UARS studied the chemical composition of Earth’s atmosphere and answered many questions about the chemical and solar processes that lead to stratospheric ozone loss. 

 HQ Contact: Beth Dickey, 202-358-2087
 For more info:

Mark Matney, Orbital Debris Scientist

(:07) Our current projection is that the spacecraft will fall sometime Friday night or early Saturday morning U.S. time. 
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(:09) In the last 24 hours something has happened to the spacecraft either in it's orientation and/or it's shape that has caused the drag rate to slow down. 
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(:33) As the spacecraft gets lower in altitude the aerodynamic forces begin to increase and several possible things can happen.  One is the orientation of the spacecraft can change.  It can weather vane or like a shuttle cock in badminton and may orient itself to present a lower profile to the aerodynamic forces.  Alternately, the forces can actually change the appendages on the spacecraft and change it's shape.  These can cause-again-the aerodynamic forces to be reduced and delay it's time of re-entry. 
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(:13) In the entire 50-plus year history of the space program no person have ever been injured by a piece of re-entering space debris.  Keep in mind that we have bits of debris re-entering the atmosphere every single day. 
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