Technical review of the Laboratory Biosphere closed ecological system facility.

Laboratory Biosphere is a 40 m3 closed life system that commenced operation in May 2002. Light is from 12,000 W of high pressure sodium lamps over planting beds with 5.37 m2 of soil. Water is 100% recycled by collecting condensate from the temperature and humidity control system and mixing with leachate collected from under the planting beds. Atmospheric leakage was estimated during the first closure experiment to be 0.5-1% per day in general plus about 1% for each usage of the airlock door. The first trial run of 94 days was with a soybean crop grown from seeds (May 17, 2002) to harvest (August 14, 2002) plus 5 days of post-harvest closure. The focus of this initial trial was system testing to confirm functionality and identify any necessary modifications or improvements. This paper describes the organizational and physical features of the Laboratory Biosphere.