Al Sacco, Ken Bowersox and Kent Rominger pose in middeck

STS073-337-021 (20 October - 5 November 1995) --- Three members of the crew check out the Zeolite Crystal Growth (ZCG) on the middeck of the Earth-orbiting Space Shuttle Columbia. Left to right are astronauts Kenneth D. Bowersox and Kent V. Rominger, mission commander and pilot, respectively, and payload specialist Albert Sacco Jr. ZCG evaluated Zeolite crystallization and growth in the microgravity environment aboard Columbia in order to achieve high yields of large, nearly perfect crystals in space. Zeolites are complex arrangements of silica and alumina that occur naturally as well as synthetically.