Materials for Transparent Inflatable Greenhouses 2003-01-2326

Long distance/duration human space missions demand economical, regenerative life support systems. With naturally available light and low atmospheric pressures, missions to the surface of Mars might employ higher plants in a bioregenerative life support systems housed within a transparent inflatable greenhouse. The primary advantages of an inflatable structure are low mass, derived from pressure stabilization of the structure, the ability to collapse into a small storage volume for transit and ease of construction. Many high performance engineering polymer films exist today that are either highly or mostly transparent. Selection of one of these materials for an inflatable greenhouse to operate in the Mars surface environment poses a number of challenges. First, materials must be strong enough to resist the differential pressure loading between the inside plant environment and the near vacuum of thin Martian atmosphere. It must also resist permeation to the contained gases and water vapor, which are ‘expensive’ to replace. At the designed thickness, the material must be transparent enough to allow sufficient natural solar irradiance to penetrate. Finally, these characteristics must prevail against the rigors of the Mars surface environment without catastrophic degradation. This paper reviews the characteristics of some available and emerging materials for their suitability for use in a Mars surface mission greenhouse.