Providing controlled environments for plant growth in space.

Abstract

Providing a controlled environment for growth of plants in a space environment involves development of unique technologies for the various subsystems of the plant growing facility. These subsystems must be capable of providing the desired environmental control within the operational constraints of currently available space vehicles, primarily the US Space Shuttle or the Russian Space Station, MIR. These constraints include available electrical power, limited total payload mass, and limited volume of the payload. In addition, the space hardware must meet safety requirements for a man-rated space vehicle. The ASTROCULTURE (TM) space-based plant growth unit provides control of temperature, humidity, and carbon dioxide concentration of the plant chamber air. A light emitting diode (LED) unit provides red and blue photons with a total intensity adjustable from 0 to 500 micromoles m-2 s-1. Ethylene released by the plant material is removed with a non-consumable ethylene removable unit. A porous tube and rooting matrix subsystem is used to supply water and nutrients to the plants. The ASTROCULTURE(TM) flight unit is sized to be accommodated in a single middeck locker of the US Space Shuttle, the SPACEHAB module, and with slight modification in the SPACELAB module. The environmental control capabilities of the subsystems used in the ASTROCULTURE(TM) flight unit have been validated in a microgravity environment during five US Space Shuttle missions, including two with plants. The unique environmental control technologies developed for the space-based plant growth facility can be used to enhance the environmental control capabilities of terrestrial controlled environment plant chambers.