High altitude balloons with ultra thin polyethylene films Original Research Article

The balloon group at the Institute of Space and Astronautical Science (ISAS) has studied to develop high altitude balloons that could reach an altitude of more than 40 km with a light payload in order to meet the requirements of observations at extremely high altitudes. In 1999, we developed a ultra thin balloon film with a thickness of 3.4 μm. It is synthesized with a new catalyst, metallocene, and has a ultimate strength of ∼650 kg/cm2 at −80°C. Using the film, we made the first balloon with 1,000 m3 in volume and 2.6 kg in weight. We launched the balloon from Sanriku Balloon Center on September 1, 1999 and it successfully reached an altitude of 37.1 km. In 2000, we prepared the second balloon with 5,000 m3 in volume with 6.8 kg in weight. It was launched on June 7, 2000 and it successfully reached an altitude of 43.0 km. Such light weight balloons are planned to be used for scientific studies in near future.