The production of synthetic zeolites represents a large ($500 - $600 million per year) commercial market. However, this market is somewhat limited by the size of crystals (4 - 10 (mu) ) normally produced on Earth. The production of large (> 100 (mu) ) crystals in significant quantities could offer a variety of new applications in the petroleum, medical, bioseparations, and waste management industries. Microgravity processing is one way to obtain these large crystals. To this end, the Battelle Advanced Materials Center for the Commercial Development of Space (CCDS) is funding the development of the Zeolite Crystal Growth (ZCG) Facility, an orbiter middeck payload currently manifested on the USML-1 Spacelab mission to be launched in June 1992. ZCG team members include Battelle, Worcester Polytechnic Institute (WPI), Teledyne Brown Engineering (TBE), and Intek, Inc. This paper describes the design and development aspects of the ZCG Facility. A brief description of the ZCG Facility, its unique operating environment inside the Shuttle Orbiter, and some of the engineering design decisions that were affected by this environment are discussed.