Amateur Radio High Altitude Ballooning
ARHAB, or Amateur Radio High Altitude Ballooning, is the application of analog and digital amateur radio to weather balloons and was the name suggested by Ralph Wallio (amateur radio callsign W0RPK) for this hobby. Often referred to as "The Poorman's Space Program", ARHAB allows amateurs to design functioning models of spacecraft and launch them into a space-like environment. Bill Brown (amateur radio callsign WB8ELK) is considered to have begun the modern ARHAB movement with his first launch of a balloon carrying an amateur radio transmitter on 15 August 1987. The first recorded ARHAB launch, however, is recorded to have taken place in Finland by the Ilamari program on May 28, 1967.
An ARHAB flight consists of a balloon, a recovery parachute, and a payload of one or more packages. The payload normally contains an amateur radio transmitter that permits tracking of the flight to its landing for recovery. Most flights use an Automatic Position Reporting System (APRS) tracker which gets its position from a Global Positioning System (GPS) receiver and converts it to a digital radio transmission. Other flights may use an analog beacon and track the payload using radio direction finding techniques. Long duration flights frequently must use high frequency custom built transmitters and slow data protocols such as RTTY, Morse code and PSK31,to transmit data over great distances using little battery power. Use of amateur radio transmitters on an ARHAB flight requires an amateur radio license.
In addition to the tracking equipment, other payload components may include sensors, data loggers, cameras, amateur television (ATV) transmitters or other scientific experiments. Some ARHAB flights carry one or more simplified packages called BalloonSats.
A typical ARHAB flight using a standard latex weather balloon lasts around 2-3 hours and reaches 25 to 35 km in altitude. Experiments with zero-pressure balloons, superpressure balloons, and valved latex balloons have extended flight times to more than 24 hours. A zero-pressure flight by the Spirit of Knoxville Balloon Program in March 2008 lasted over 40 hours and landed off the coast of Ireland, over 5400 km from its launch point.
The largest annual gathering of ARHAB groups is called the Great Plains Super Launch (GPSL) and usually occurs near the Fourth of July weekend.
References
73 Magazine, August 1991 (defunct amateur radio publication)