Table of Contents

SAREX

When Columbia launches this summer, it will also carry the Shuttle Amateur Radio EXperiment (SAREX), a low-power, hand-held amateur radio station capable of communicating with other stations on the ground which will be within our line-of-sight. For STS-78, our onboard station will be limited to voice and packet capability. The major onboard components will include a 2m FM transceiver (Motorola MX-360 HT); a packet module (Heathkit HK-21 TNC); a 2.5 watt cavity antenna which will be mounted in one of the orbiter's side windows; and a laptop computer with satellite tracking, packet and editor software. A microcassette recorder will be used for logging QSOs. This station configuration will be capable of operating in the attended mode for voice communications or the automatic  mode for packet communications.

SAREX is sponsored by NASA, the American Radio Relay League (ARRL) and the Radio Amateur Satellite Corporation (AMSAT) and is supported on a volunteer basis by amateur radio clubs at the various NASA space centers. It is classified as a secondary payload aboard the shuttle which means that due to higher priority mission responsibilities, my colleagues and I will have limited time for voice communication. When we will have free time (during our breaks, before and after meals, or prior to sleep), we will make unscheduled two-way voice contacts with amateur radio operators around the world. Because of our low orbital inclination (39o), low altitude (150 nm) and gravity-gradient attitude (i.e. tail of the shuttle towards the Earth and its belly in the direction of the velocity vector), I expect that QSOs with Canadian operators will be challenging, but not impossible. To maximize your chance of communicating with us, you may need to track Columbia's path with spacecraft tracking software and the Keplerian orbital elements which are based on the shuttle's actual launch time and the characteristics of its orbit. The software will then use this data to calculate when the shuttle will be within range of your station and where to point your antenna. If attempting a voice contact, you must also consider when my crew mates and I will be awake (our wake times will be similar to those living in the Central time zone).

Most of our passes over North America will be during daytime. We will either use the shuttle's call sign, W5RRR, or our individual call signs. The frequencies for two-way voice communication with the shuttle will be 145.55 Mhz for the downlink and 144.91, .93, .95, .97 and .99 for the uplinks (different uplink frequencies are used when we overfly Europe). We will not favour any specific uplink frequency, so your ability to communicate with us will be a matter of being in the right place, on the right frequency, at the right time. In addition, we ask that you observe the following procedures: when calling, say your complete call sign, not just the suffix; speak slowly and clearly; use phonetics; keep the contact short; consider the doppler shift due to our orbital velocity (28,000 kph); don't transmit on the downlink frequency; transmit on the uplink frequency only when the shuttle is in range and we are on the air; listen to the uplink frequencies before transmitting to avoid interference with other operators.

An elaborate station setup is not required to make contact with the shuttle. An effective radiated power of 25 to 100 watts will give good results. A fixed antenna such as a turnstile or a single vertical monopole mounted above obstructions will work well. Better still would be a directional beam antenna pointed at the shuttle as it crosses the sky.

You may also use shortwave radio to eavesdrop on our air-to-ground audio communications with Mission Control. These communications as well as NASA mission commentary and SAREX bulletins are retransmitted live by the Goddard Space Flight Center's amateur radio club in Maryland. Listen on the HF bands at 3.86, 7.185, 14.295, 21.395 or 28.65 Mhz.

When we leave the SAREX radio unattended, we will keep the packet system in automatic mode as much as possible. The packet call sign will be W5RRR-1 and frequencies will be 145.55 Mhz for the downlink and 144.49 for the uplink.

Educational Goal

While SAREX provides an opportunity for radio amateurs around the world to talk with shuttle astronauts in orbit, its primary goal is an educational one. NASA and the other sponsors use amateur radio to spark student interest in the science, technology and communications fields by bringing the international space program directly into the classroom. Several grade schools from around the world have been selected for prearranged QSOs with my crew. Pre-flight preparation by these schools includes setting up a ground station (with the assistance of local amateur radio clubs), designating students to talk to the astronauts, selecting questions to be asked during the contact, informing the press and preparing for the big day. Many schools conduct radio operation drills and simulations before the actual flight. Teachers typically involve a large number of students in the event by integrating the activity into the school curriculum.

During LMS, I will speak with students at the Maple Grove Education Center in Hebron, Nova Scotia and at College Park School in Saskatoon, Saskatchewan. Other schools in the United States, Australia, Great Britain and France will be contacted by my crew mates. Columbia's low altitude and orbital inclination during STS-78 will necessitate the use of a telebridge to relay communications to the two Canadian schools on telephone lines from other ground stations. The telebridge system consists of an international network of ground stations which can be linked to school groups using telephone conferencing systems.

I believe that these educational contacts will be the greatest benefit of SAREX during the LMS mission. Through this amateur radio project, we will portray mathematics, science and technology as exciting and relevant to Canadian young people.

The Future

I hope to have the opportunity to speak with several Canadian amateurs during my mission. If you are unable to make contact with us, there will be other opportunities in the future. SAREX is scheduled to fly on STS-79, -80 and -81. Two of these missions are at higher orbital inclinations than that for LMS. Note that on Mir docking missions, the shuttle uses a different set of frequencies for SAREX voice contacts: 145.84 Mhz for downlink and 144.45 and 144.47 for uplink. On future missions, SAREX may fly in other configurations which include slow and fast scan amateur TV capability.

Due to the growing enthusiasm for amateur radio amongst the astronaut corps, SAREX is now requested by crews for almost every shuttle flight. However, due to the volunteer nature of the program and its limited budget, it only flies on about four missions per year. That may change when the International Space Station is in orbit. You can be sure that SAREX will be a permanent fixture aboard the Station providing recreational diversion for the onboard astronauts and an exciting challenge for radio amateurs on the ground.

Further information about the SAREX program can be obtained from the ARRL at (860) 594-0301 or in The Canadian Amateur Canada's Amateur Radio Magazine Vol. 24 No. 6 June 1996.