Ham Radio on the ISS:

Amateur Radio on the International Space Station
By: Ted N.
Copyright 2003, Astronomical Society of Harrisburg. Not to be used or posted elsewhere without permission.

Floating above us at over 15,000 miles per hour, circling the Earth once every 90 minutes, 2 astronauts and 1 cosmonaut are manning the International Space Station, Alpha. Still being assembled, the station, like the Mir, has Amateur Radio onboard. After successful amateur operations on the Mir and Shuttle, ARISS was formed, and will build and operate equipment aboard the station with the help of AMSAT, the ARRL, and other organizations. The current expedition aboard the station is Expedition 4, and consists of Russian cosmonaut and Station Commander Yuri Onufrienko, and US astronauts Daniel Bursch and Carl Walz

The ISS's Current Configuration, courtesy of NASA.

The equipment being used by residents is located in the Zarya module and consists of two handheld Ericsson transceivers, a power adapter, a packet module, a headset assembly, and the required cable assemblies. The station is capable of operating in voice and packet mode with stations within line-of-sight of the ISS. The two transceivers on board have voice and packet capability on 2 meters and 70 cm. The power adapter consists of a 12V to 7.5V DC/DC power converter that converts the 12 VDC received from the power supply in the packet module to 7.5 VDC that powers the transceiver. So far 2 antennas are installed outside the station, a VHF/UHF antenna, and an HF antenna. The VHF-UHF antenna is currently being used, but the HF is not because there is no equipment on board yet to run HF. The HF antenna is a 2.5-meter (8.2-foot) long flexible tape type antenna believed to operate on 10, 15, and 20 meters. It is not yet known when HF equipment will be installed aboard the station, but slow scan TV is also on the list of to be installed equipment.

Here are the current frequencies being used by the ISS: General QSO's Voice and Packet Downlink: 145.80 (Worldwide), Voice Uplink: 144.49 for Regions 2 and 3 (The Americas, and the Pacific), Voice Uplink: 145.20 for Region 1 (Europe, Central Asia and Africa), and Packet Uplink: 145.99 (Worldwide). The callsigns being used by the Russians are RS0ISS, and RZ3DZR. Americans are using NA1SS. The packet station mailbox callsign is RZ3DZR-1 and the packet station keyboard callsign is RZ3DZR.

The current equipment being used by Station Residents to make contacts, courtesy NASA.

To make contact with the space station here are some suggestions, you'll need a 2-meter FM transceiver capable of between 25 and 100 watts of output power. Antenna wise, a circularly polarized crossed-Yagi antenna capable of being pointed in both azimuth (N-S-E-W) and elevation (degrees above the horizon) is desirable, though contacts have been made with verticals and ground plane antennas. Computer software is available to help track the ISS, and to predict when it will be passing overhead. A good website to visit for passes is www.heavens-above.com.

Do keep in mind though; the major function of amateur radio aboard the station is outreach to schools and other groups. Though, it is still possible to make a contact with an astronaut or cosmonaut during their breaks, pre-sleep time and before and after mealtimes. However, it may take several times before you actually reach them, so patience will eventually pay off, they are very busy people up there. Nevertheless, the astronauts aboard have contacted thousands of hams around the world. They are also using computer software on the station, which allows the crew to operate the 2-meter packet gear radio in unattended mode, and hams can make contacts when the crewmembers are working.

More information on Amateur Radio aboard the ISS is available at these websites:
http://spaceflight.nasa.gov/station/reference/radio/
http://ariss.gsfc.nasa.gov/

Expedition 3 Commander Frank Culbertson works the Boy Scouts from aboard the station, courtesy ARISS/NASA.