How would you like to put a signal through the International Space Station, as it sweeps across the horizon in it's Low Earth Orbit? Well, with an Amateur Radio license, you can do just that, on the 2m VHF band!

Equipment

To operate via ISS, you will need the following equipment:

1. A 2m (144-148MHz) FM transceiver, capable of split frequency operation (this includes almost all handhelds and mobile radios)
2. A "standard" 1200bps AX.25 TNC (Terminal Node Controller), as used on the amateur terrestrial packet network since c.1986
3. Almost any 2m antenna (a simple quarter-wave whip will work!)
4. A simple terminal program (such as Hyperterminal), or some other way to communicate with the TNC.

Of course, you can use other combinations that have the same effect, such as the simple "Baycom" modems, or a "soundcard modem", driven by software such as the SV2AGW Packet Engine.

Radio Configuration

Set your radio to Receive on 145.800MHz, and to Transmit on 145.990MHz. In other words, 145.800MHz with a positive split of 190kHz.

TNC Configuration

1. Set your callsign (eg MYCALL VK6KCH)
2. Set the unproto path to CQ v WIDE,[gridsquare[ (eg UNPROTO CQ v WIDE,OF78wb)
3. Make sure your beacon is turned off (eg B E 0)

That's pretty well all that's needed!

When's ISS Visible?

ISS is available roughly six times a day; the exact pass times and duration vary depending on your location, and vary from day to day.

Ideally, you should get some software from AMSAT (such as Instant Track), and use that to track the coverage. Alternatively, you can use online prediction services such as Heavens Above. It is worth entering your own co-ordinates as accurately as possible, but an easy approximation for Perth, is Latitude = 32 degrees South, Longitude = 116 degrees East. (Those co-ords are actually in Forrestfield).

Operation

To start with, just monitor 145.800MHz, to get a feel for operation! ISS transmits a beacon once every minute, along the lines of:

     1:Fm RS0ISS-3 To P0PPP0 Via SGATE,WIDE <UI pid=F0 Len=31 >[17:27:17]
     'vXl '/]APRS/BBS & PACKET ON

When you feel you've got the hang of it, place your TNC into "Unproto" mode (eg UNPROTO), and then send a message, always starting with an ">". For example:

>Hi from Perth!

You should hear and see your own packet digipeated through ISS, with "WIDE" in the path replaced with RS0ISS-3. Congratulations, you just sent a message via the International Space Station!

So, Who's Already There?

You can see a list of the latest Amateur Stations heard via ISS, at http://www.ariss.net/

VK stations include VK3JFK, VK3UKF, VK4CAU, VK6DM, VK6KRB and VK6KCH.

What About Voice?

ISS also carries an UHF uplink, and is occasionally used in voice mode, either as a cross-band repeater, or for voice contacts with the ISS crew themselves!

For more information on Amateur Radio on the ISS, see http://www.amsat.org/amsat-new/satellites/status.php#ISS

Good luck, and we look forward to seeing you via ISS!