International Space Station (ISS)

Thanks to some great work by the ARISS Team, a new Voice Repeater system is operating on the International Space Station! Here is the access information:

• Mode: FM Voice
• Uplink Frequency: 145.990 MHz, PL 67.0 Hz
• Downlink Frequency: 437.800 MHz

IORS Hardware and Kenwood Radio

The repeater uses the new InterOperable Radio System (IORS), a space-modified JVC Kenwood D710GA transceiver, and an ARISS developed power supply system.

Kenwood D710GA

Here’s some more information from the ARISS Press Release:

The ARISS team is pleased to announce that the setup and installation of the first element of our next-generation radio system was completed and amateur radio operations with it are now underway. This first element, dubbed the InterOperable Radio System (IORS), was installed in the International Space Station Columbus module. The IORS replaces the Ericsson radio system and packet module that were originally certified for spaceflight on July 26, 2000.

The initial operation of the new radio system is in FM cross-band repeater mode using an uplink frequency of 145.99 MHz with an access tone of 67 Hz and a downlink frequency of 437.800 MHz. System activation was first observed at 01:02 UTC on September 2. Special operations will continue to be announced.

The IORS was launched from Kennedy Space Center on March 6, 2020, on board the SpaceX CRS-20 resupply mission. It consists of a special, space-modified JVC Kenwood D710GA transceiver, an ARISS developed multi-voltage power supply, and interconnecting cables. The design, development, fabrication, testing, and launch of the first IORS was an incredible five-year engineering achievement accomplished by the ARISS hardware volunteer team. It will enable new, exciting capabilities for ham radio operators, students, and the general public. Capabilities include a higher power radio, voice repeater, digital packet radio (APRS) capabilities, and a Kenwood VC-H1 slow-scan television (SSTV) system…

You can view the full ARISS Press Release here.

I was able to work several stations using the new ISS Voice Repeater this morning. It is very sensitive and uses 5 watts of downlink power with a good antenna on the ISS. I was able to make solid contacts using the Ground Station here using only 1.5 watts uplink power when the ISS was at 10 degrees above the horizon. At least one of my contacts was with a station using an HT with a whip antenna!

The voice repeater is sensitive enough and uses a power level that will enable folks with an HT and a whip antenna to make contacts using the ISS when it is close to the horizon. It should also be easy to make contacts using mobile rigs that can support cross-band operation as well. Program your radios!

I’m looking forward to working you through the ISS!

Fred, AB1OC