Scientific ballooning in India

Abstract

The programme of development of large polyethylene balloon technology to carry large and heavy experimental payloads to stratospheric altitudes for cosmic ray research was initiated in the Tata Institute of Fundamental Research (TIFR), Bombay, in March 1956. After initial trials and tribulations, first successful balloon flight using black or tinted polyethylene balloon grade film was conducted in 1958. Regular balloon flight programme from Hyderabad was initiated in 1959 – first from the Osmania University Campus grounds and later, beginning December 1969, from the TIFR National Balloon Facility (TNBF), Hyderabad. Various aspects of scientific balloon technology – balloon design, fabrication, launch methods – were developed by the TIFR balloon group. As the black balloon could be used only for the day flights, a programme of development of new transparent (white) balloon film suitable for balloons to be flown for night flights was initiated in 1970-71. First success with ‘white’ balloons was achieved in 1973-74. Further attempts in the development of better balloon grade film continued and recently a balloon grade film with cold brittle point (CBP) close to - 90°C has been developed and actually used in a successful balloon flight. Various aspects of balloon design specifications more suitable to balloon launches from equatorial latitudes have also been developed and successfully implemented. Some of the important features of the development of balloon technology in India are presented.