and converts it to a digital radio transmission. Other flights may use an analog beacon and are tracked using radio direction finding techniques. Long duration flights frequently must use high frequency custom-built transmitters and slow data protocols such as radioteletype (RTTY), Hellschreiber, Morse code and PSK31, to transmit data over great distances using little battery power. The use of amateur radio transmitters on an ARHAB flight requires an amateur radio license, but non-amateur radio transmitters are possible to use without a license. In addition to the tracking equipment, other payload components may include sensors, data loggers, cameras, amateur television (ATV) transmitters or other scientific instruments. Some ARHAB flights carry a simplified payload package called BalloonSat. A typical ARHAB flight uses a standard latex weather balloon, lasts around 2–3 hours, and reaches 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 from its launch point. On December 11, 2011, the California Near Space Project flight number CNSP-11 with the call sign K6RPT-11 launched a record-breaking flight traveling from San Jose, California, to a splashdown in the Mediterranean Sea. The flight lasted 57 hours and 2 minutes. It became the first successful U.S. transcontinental and the first successful transatlantic amateur radio high-altitude balloon. Since that time, a number of flights have circumnavigated the Earth using superpressure plastic film balloons. Each year in the United States, the Great Plains Super Launch (GPSL) hosts a large gathering of ARHAB groups. BEAR program Balloon Experiments with Amateur Radio (BEAR) is a series of Canadian-based high-altitude balloon experiments by a group of Amateur Radio operators and experimenters from Sherwood Park and Edmonton, Alberta. The experiments started in the year 2000 and continued with BEAR-9 in 2012, reaching . The balloons are made of latex filled with either helium or hydrogen. All of the BEAR payloads carry a tracking system comprising a GPS receiver, an APRS encoder, and a radio transmitter module. Other experimental payload modules include an Amateur Radio crossband repeater, and a digital camera, all of which is contained within an insulated foam box suspended below the balloon. BalloonSat A BalloonSat is a simple package designed to carry lightweight experiments into near space. They are a popular introduction