This text contains papers from the 1997 Lighter-Than-Air Systems Technology Conference and 1997 AIAA International Balloon Technology Conference. The special focus for the Lighter-Than-Air Systems Technology Conference is placed on: market analysis; awareness; communications; lighter-than-air applications; vehicle certification; design and analysis; design concepts; materials; and environmental characteristics. Paper topics from the AIAA International Balloon Technology Conference include: vertical and trajectory performance modelling; balloon design and structural analysis; structural and materials failure criteria; materials characterization; development and processing; balloon and payload thermal analysis; balloon and payload stability and control; systems design and operations; and reliability and quality assurance.