[sarex] ISS Recovers From Power Loss

Arthur Rowe azrowe80 at verizon.net
Mon Feb 12 09:45:14 PST 2007


SUBMITTED BY ARTHUR N1ORC - AMSAT A/C #31468

*Station Recovers From Power Loss*

Mission control teams are working to assess systems affected by a power 
loss aboard the International Space Station early Sunday morning. The 
station's three crew members were not in any danger, but it did turn an 
off-duty day into a full work shift.

About 1 a.m. EST, one of the power channels of the P4 solar array 
electrical system went down because of a glitch with a device known as a 
direct current switching unit. It controls power distribution from the 
solar array to the battery systems and other hardware. The glitch 
resulted in a temporary loss of communications, and shut down some 
equipment, including a few science facilities and heating units and 
control moment gyroscope #2. The station never lost orientation control, 
but it operated most of the day with two of four gyros. Control moment 
gyroscope #3 previously had been powered down.

Flight controllers restored power to nearly all affected systems and 
equipment by Monday morning. They are still investigating what caused 
the glitch, but they believe it was an isolated event.



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