For anybody writing a novel about the ISS that needs the station to be out of communication with the earth for a while

It seems that it can happen. Must be pretty scary for the guys on the ground. Less so for the guys at the station.

I know that there routinely periods of time (minutes rather than hours) when the station is handed off from one communications net to the next during which they are incommunicado. But 31 hours is a long time.