[amsat-bb] Current ARISS Status/Usage?

I finally got my TNC hooked up, and was able to decode APRS packets. I wanted to try during a rather low ISS pass, see what I could get off of ISS, but got nothing. I tried both 145.825 and 145.8, hearing neither voice nor data.

In fact, I've never heard anything on ISS (except for the one scheduled contact I made with it :-D).

Is it currently operational for voice and/or packet? How often is someone likely to be using it (what are my chances of hearing something on any given pass)?

TIA,