“The payloads are attached to a sounding balloon which climbs to over 100,000 ft. The balloon is tracked with GPS telemetry systems. When the balloon is launched, it is about 12 ft. in diameter. At peak altitude it is between 40-50 ft. in diameter before burst (or commanded cut-down).” — PentaxForums.com
Photos from arena_5. View the complete ASTRO-09 set. Via zyrcster in Flickr Central.