APRS-IS is an amateur APRS station that is operating from the International Space Station. The ISS has an APRS digipeater on board and will beacon packets back to earth. Its identification is RS0ISS and ARISS.

How do I work the ISS with APRS?
If you want to work the ISS, first you need to make sure the digipeater is up and running. You can find that info here: https://www.n2yo.com/satellite/?s=25544 – look for an entry that looks like this.

Here is what you need to make the contact:
2-meter FM radio + radio interface or TNC
2-meter antenna – You can use a yagi, but a vertical is fine.
A device capable of APRS (PC, Android, Raspberry Pi, etc)
You can verify that the station works by checking the standard APRS frequency: 144.39 FM

Set your frequency to 145.825. Since we are on 2 meters, there is some Doppler shift, but not as much as higher frequencies. If you widen your filter, you won’t need to adjust the Doppler shift frequency.