Fresh Vegetables in Space: From Spaceflight Experiments to Space Plant Production

Abstract

By utilizing space vehicles in low earth orbit (LEO), the effects of a space environment on plant growth and development have been investigated, and improvements of environmental control for growth of plants in space have been made. As plants have evolved their survival strategy by adapting to Earth gravity, attention has been paid particularly to the gravitational biology of plants. For example, spaceflight experiments with cucumber seedlings have shed light on the new concept of gravimorphogenesis and provided evidence of gravitropic interference with root hydrotropism, yielding important clues to the mechanistic processes involved. Based on our knowledge to date, humans are beginning to plan crop cultivation in deep space environments such as the Moon and Mars to support long-term habitation. To achieve this goal of space plant production, it is necessary to understand the composite effects of multiple space environmental cues such as low gravity, cosmic rays and solar radiation on plant growth. In addition, there will be a need to develop new crop cultivars and techniques for highly efficient cultivation, as well as for resource recycling and circulation in a closed system suitable for a space environment. Thus, plant space biology and its application to space farming should provide a roadmap for future space exploration by manned missions.