Amateur Radio on the International Space Station

From time to time there is a variety of amateur radio activity from the International Space Station (the ISS).  There are occasional planned contacts with schools around the globe.  Sometimes it is also possible to have a contact with an off-duty astronaut.  Probably the most popular way is to receive slow scan television (SSTV) images from the ISS.   

Receiving SSTV from the ISS

From time to time, the astronauts on the International Space Station (ISS) transmit some Slow Scan Television (SSTV).  Here are a few quick notes which will help you to get going.

Dates & Times

You’ll need to keep an eye on the AMSAT web site to keep up to date with forthcoming activity.

Frequency and RF Mode

145.800 MHz FM.  Try a vertically polarised antenna.  It is likely that 25kHz (rather than 12.5kHz) bandwidth may give better results. 

International Space Station Orbits (Passes)

Below is an example of a schedule of passes.   

 

Date

Start

Highest point

End

Time

Alt.

Az.

Time

Alt.

Az.

Time

Alt.

Az.

31 Jan

20:48:47

10°

S

20:50:29

14°

SE

20:52:16

10°

ESE

31 Jan

22:23:14

10°

SW

22:26:27

54°

SSE

22:29:42

10°

ENE

01 Feb

21:31:11

10°

SW

21:34:14

37°

SSE

21:37:20

10°

E

01 Feb

23:07:17

10°

W

23:10:35

82°

N

23:13:54

10°

E

 
The best passes are the ones that have a high figure in the Alt column (Highest Point). 

Each pass lasts for up to about 10 minutes, and should yield at least one, and sometimes two or three SSTV images.  Note that there are usually gaps of about 3 minutes between each picture being sent.

When are the passes

Click on http://www.amsat.org/amsat-new/tools/predict/ use the locator of IO80XR which will give good predictions for the Poole/Bournemouth area. 

 

Listen for SSTV signals between the AOS and LOS times (note these are in UTC not BST).  Remember there are gaps of about three minutes between pictures, so don’t worry if can’t hear anything when you might otherwise expect to!  Any passes where the maximum elevation is below about 10 to 15 degrees are unlikely to yield good signals due to local obstructions, unless you have a good take-off to the horizon.

Where is the International Space Station (ISS) Now?

The ISS moves across the earth very fast indeed.  You may be surprised just how far it travels in just a few minutes!  You can see where the ISS is currently located by clicking on

 http://www.amsat.org/amsat-new/tools/predict/satloc.php?lang=en&satellite=ISS 

What Software do I need to receive SSTV?

Suggested software for the PC is MMSSTV which can be downloaded from this link MMSSTV  Don’t forget to set the mode to PD180

SSTV Format

You’ll need to check the actual SSTV mode being used by the ISS.  It is often PD180 on 145.800 MHz with a gap of a minute or two between periods of transmission.

How do I connect the rig to the computer?

Connections – connect the external loudspeaker output of your rig to the line input socket of your computer’s soundcard (often coloured light blue).  If no line input socket, then use the microphone input socket (often coloured pink/mauve).  You will probably need 3.5mm stereo jack plugs.  Leave the Ring unconnected.

 

Hints & Tips

There are gaps of up to about three minutes between each picture being sent.  So don’t worry if you can’t hear anything when you think you should.  Just keep listening.