Working the International Space Station (ISS)

Since this information changes, last updated:

June 2nd, 2021

If you have ever been interested in making contacts with the ISS also known as the International Space Station then you are on the right page.

There are several ways you can go about this, depending on operating schedules and gear on-board. The best known of course is making contacts with the astronauts. This is generally done with schools and by arrangement. If you hear one of the above, please do not interrupt them. Only call if you are hearing a CQ or hear a pileup but please be sure to let QSOs finish. Often you can hear ISS calling CQ before a scheduled school contact. Best thing to do is have a dedicated receiver ready when there is a predicted pass. Passes are SHORT, as in about only 10 minutes! ISS is lower then AMSAT satellites and MUCH lower the Geostationary satellites (such as DirecTV for example) which do not move.

There is an APRS repeater as well as a the occasional SSTV transmission. SSTV is one way, receive only! Please do not try and send back an SSTV image with a reply as you would on the HF bands generally speaking. Details are subject to change so please check this often.

Currently used Frequencies by the ISS:

  • Voice & SSTV Downlink: 145.80 MHz (Receive ONLY)
  • Voice Uplink: 144.49 MHz for ITU Regions 2 & 3 - Americas, Southern Asia and Pacific
  • Voice Uplink: 145.20 MHz for ITU Region 1 - EU, Northern Asia, Africa

Packet/APRS:

  • VHF Packet Uplink and Downlink: 145.825 MHz
  • UHF Packet Uplink and Downlink: 437.550 MHz

FM Repeater:

  • FM Repeater Downlink (UHF): 437.80 MHz (Do NOT transmit here!)
  • FM Repeater Uplink (VHF): 145.99 MHz / PL Code: 67Hz

Television:

  • DATV (Ham TV) Downlink:  2395.00 MHz

Uplink is where you transmit, Downlink is Receive. Some are simplex, same RX and TX frequency, such as Packet/APRS. PL Code is used to gain access to the repeater, you can read more about this here. For FM Voice Downlink and SSTV downlink (receive ONLY) NEVER, under any circumstance transmit here!

Callsigns used are NA1SS (USA) and RS0ISS (Russian) as well as others depending on who is up there. Check the Ariss.org page for current info on this.

Here is an example of the image you might be able to receive via SSTV. This was received July 7th, 2018 on 145.8 MHz using the PD120 format. (Image is clickable for a larger view)

Recommended Reading (See below for more):

For information on Ham Radio Satellite Frequencies click HERE.

For Information on How to get started on Ham Radio Satellites click HERE>

Useful links related to the topic:

If you find something incorrect, have an update, or if there is something you would like to see added, drop me a line here. I like to keep things as up-to-date and as accurate as possible. Thank you! - Lucas / W6AER

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