Communication with ISS disrupted (update: restored!)

CNN and others are reporting that NASA has lost normal communications with the International Space Station.  It seems that a routine computer update didn't go as planned, disabling some of the communication system.  The station has reverted to backup communications, which means that it can only transmit as it passes over a ground station in Russia, similar to how communication was handled in the pre-Apollo era.  This disruption poses no immediate threat to the astronauts or orbiting laboratory, but will surely cause NASA quite the headache.  More as this story develops.

Update: After less than three hours, full communication has been restored to the station.  NASA has yet to determine the exact reason for the disruption, but it appears that a communication relay malfunctioned while sending a computer update to the facility's flight computers.