[amsat-bb] aprs iss freq: is there anyone out there?

Are there any stations in South America to gate aprs packets to the net from the uhf freq? How does one do this? I've got a few Byonics TT4's from a balloon project. The story: I'll be driving the Panamerica Sur from Lima to Nazca Peru and would like to have the ability to be seen via the net. Norm n3ykf