A solar balloon or solar airship, is a hot air balloon which gains buoyancy by using only radiation from the sun; the balloons are generally made from black material, which helps them to heat up in the sunshine. This causes the air present inside the solar balloon to expand and reduce in density compared with the surrounding air. As such, the balloon functions like a hot air balloon. Some solar balloons are large enough for human flight. A vent at the top can be opened to release hot air for descent and deflation.
A completely different concept is a solar airship where the "solar" term describes the propulsion rather than the lifting characteristic. This is a gas airship partially covered with solar cells which power an electric motor and motive propeller.
First manned flight
The first human carrying pure solar balloon flight was made on the 1st May 1973 by Tracy Barnes in his balloon 'Barnes Solar Firefly Tetrahedron'. This balloon was made from a spiral tube of fabric that was formed into a tetrahedron. Dominic Michaelis is recorded as having owned the first pure solar balloon in Europe. This balloon was flown by Julian Nott across the English Channel. Records compiled for the FAI show that on 6th February 1978 Frederick Eshoo also made a solar flight in a balloon called Sunstat.
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| Solar balloon |
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| Tube Solar Balloon |
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| Standard Solar Balloon |
