Montgolfier brothers Montgolfier brothers Joseph-Michel Montgolfier (26 August 1740 – 26 June 1810) and Jacques-Étienne Montgolfier (6 January 1745 – 2 August 1799) were paper manufacturers from Annonay, in Ardèche, France best known as inventors of the Montgolfière-style hot air balloon, globe aérostatique. They launched the first piloted ascent, carrying Étienne. Joseph Michel also invented the self-acting hydraulic ram (1796), Jacques Étienne founded the first paper-making vocational school and the brothers invented a process to manufacture transparent paper. The Montgolfier brothers Joseph-Michel and Jacques-Étienne were born into a family of paper manufacturers founded in 1534 in Annonay, in Ardèche, France. Their parents
Hot air balloon fabric needs to be replaced. Many balloon pilots operate their envelopes at temperatures significantly less than the maximum to extend envelope fabric life. The lift generated by 100,000 ft³ (2831.7 m³) of dry air heated to various temperatures may be calculated as follows: The density of air at 20 °C, 68 °F is about 1.2 kg/m³. The total lift for a balloon of 100,000 ft³ heated to (99 °C, 210 °F) would be 1595 lb, 723.5 kg. This is just enough to generate neutral buoyancy for the total system mass (not including the heated air trapped in the envelope, of