Hey guys thought I would drop a note regarding APRS to the ISS. I successfully pulled it off the other day and even saw my message come up on the APRS logs in Outernet, so that is kind of fun (just think, it went from earth to space twice!). I wanted to let anyone else who wanted to try this know that there has been a change in the APRS frequency for ISS since last November. In October their normal radio went dead. They pulled out a backup and hooked it up for APRS, but it is on UHF. The frequency is 437.550. UHF is more susceptible to doppler so they recommend you program a set of channels and shift during the pass. This is how I set mine up.
The good news is that they should be back up and running on VHF sooner rather than later because the new radio was just delivered today!