Can I use amateur radio to communicate with the International Space Station (ISS)?

Yes, you can use amateur radio to communicate with the International Space Station (ISS). The ISS is equipped with an amateur radio station, and astronauts onboard often participate in amateur radio activities during their free time. The Amateur Radio on the International Space Station (ARISS) program, supported by several national amateur radio organizations and space agencies, facilitates these activities, which include voice contacts, digital packet radio, and Slow Scan Television (SSTV) transmissions.

Here’s how you can communicate with the ISS using amateur radio:

Voice Contacts

Astronauts onboard the ISS occasionally make voice contacts with amateur radio operators on Earth during their free time. These contacts typically take place on VHF frequencies using FM mode. The ISS usually operates on a frequency of 145.800 MHz for downlink (receiving) and 144.490 MHz for uplink (transmitting) in regions 2 and 3 (which include the Americas, the Pacific, and Asia). In region 1 (Europe, Africa, and the Middle East), the uplink frequency is 145.200 MHz.

Keep in mind that voice contacts with the ISS are relatively rare, as they depend on the availability and interest of the astronauts. It’s essential to monitor the ARISS website (http://www.ariss.org/) and social media for announcements regarding scheduled voice contacts.

ARISS School Contacts

ARISS organizes scheduled voice contacts between the ISS and schools, educational institutions, or public events. These contacts aim to inspire students in science, technology, engineering, and mathematics (STEM) fields and promote amateur radio. While only the selected institutions can transmit to the ISS during these events, other amateur radio operators can listen to the downlink on 145.800 MHz.

Digital Packet Radio

The ISS also supports digital packet radio communication using the AX.25 protocol. Amateur radio operators can use a VHF transceiver, a Terminal Node Controller (TNC), or a sound card interface to connect their computer to their radio and exchange messages with the ISS and other stations through the ISS digipeater. The digipeater operates on a frequency of 145.825 MHz (uplink and downlink) in most regions.

Slow Scan Television (SSTV)

Occasionally, the ISS transmits SSTV images on a frequency of 145.800 MHz. These images can be received by amateur radio operators using a VHF transceiver and SSTV decoding software on their computer or smartphone. SSTV events are usually announced in advance on the ARISS website and social media.

To successfully communicate with the ISS, you’ll need to track the ISS’s position in the sky and adjust your radio equipment accordingly, much like working with other amateur radio satellites. Keep in mind that the ISS orbits the Earth at a much higher speed, and its passes are relatively short, usually lasting around 10 minutes or less.

By following these guidelines and staying informed about the ISS’s amateur radio activities, you can have the unique opportunity to communicate with the International Space Station and the astronauts onboard.