The International Space Station (ISS) orbits Earth every ~90 minutes, completing roughly 16 laps per day at a speed of nearly 28,000 km/h (17,500 mph). On a clear evening, you can often see it gliding overhead for 4–8 minutes at a time. But what’s even more exciting: you can sometimes hear it, and even communicate through it, using your existing VHF/UHF gear.

📡 ARISS – Amateur Radio on the International Space Station
ARISS (Amateur Radio on the International Space Station) is a partnership between international space agencies (NASA, ESA, JAXA, CSA, and Roscosmos) and the worldwide ham community.
It allows astronauts to contact schools, experiment with ham gear, and provide access for amateurs around the world to make brief contacts through the onboard systems.

The ISS currently supports:
145.825 MHz FM → APRS digipeater (active most of the time).
Use your handheld or mobile rig and you can receive — or even relay — short digital messages that travel through space!

Voice Repeater (when enabled):
Uplink 145.990 MHz (PL 67.0 Hz) / Downlink 437.800 MHz FM
When active, this allows licensed amateurs to make quick simplex contacts via the ISS repeater during visible passes.
Mode changes (between packet, voice, or cross-band repeater) are managed by ARISS — you can check the current operating mode at www.ariss.org/current-status-of-iss-stations.html

🕒 How to Catch a Pass
Because the ISS travels so quickly, you’ll only have a few minutes of good access on each pass — usually between 1 and 4 visible opportunities each day per location.

Here’s how to plan:
🔭 Visual pass info: spotthestation.nasa.gov
🌍 Full tracking: heavens-above.com
(custom maps & TLE-based predictions)

🎧 How to Listen
Even a basic 2 m / 70 cm dual-band handheld with a stock antenna can hear ISS transmissions on a strong pass.

For better results, use:
Set Doppler-shift offsets (~±3 kHz on 70 cm) as the ISS moves overhead.