Inflatable Moon Base Concept for Lunar Poles Revealed by ESA
An inflatable Moon base concept has been revealed by ESA based on a study conducted by Inflatable structures specialist Pneumocell in Austria.
The vision is for a future lunar habitat assembled from semi-buried inflatable habitats. Sited beside the lunar poles in regions of near-perpetual solar illumination, mirrors positioned above each habitat would reflect sunlight into greenhouses within the doughnut-shaped habitats.
Once inflated, these habitats would be buried under 4-5 meters (≈13-16 feet) of lunar regolith for radiation and micrometeorite protection. Above each habitat a truss holding a mirror membrane would be erected, designed to rotate to follow the Sun through the sky. Sunlight from the mirror would be directed down through an artificial crater, from which another cone-shaped mirror reflects it into the surrounding greenhouse.
According to the executive summary of the proposal, the inflatable Moon habitat structure consists of room modules that can be connected to extend the habitat. The main inflatable modules are toroidal greenhouses with a minor diameter of about 5.20m (≈17 feet) and a major diameter of 22.20m (≈73 feet). These greenhouses are connected among each other by a tunnel system and additional modules for living and working areas are attached to their outer side.
Modular Design Allows for Inflatable Moon Base Expansion
The habitat can start with one greenhouse unit and grow by adding more greenhouse units. In the document, Pneumocell suggests a “village” consisting of 16 greenhouse units that are placed in a double linear arrangement, in order to minimize mutual shadow casting among the mirror towers, when the Sun moves along the lunar horizon. Greenhouses, living areas and connecting tunnels are all made of double-layered inflatable foils, while the towers carrying the upper mirrors are a low weight construction consisting of carbon fiber tubes. Moreover, a redundancy of the corridors keeps the parts connected even if some parts are destroyed in an accident.
The regolith layer that covers the inflatable Moon base modules acts as a very effective thermal isolation between the interior of the greenhouses and the surrounding environment, as has been verified by a numerical model in the frame of this project. The upper mirrors reflect the nearly horizontally arriving sunlight into an artificial crater at the geometric center of the torus, from where it is directed into the greenhouse via another conical mirror and through a window consisting of two transparent foils.
In order to save weight, all mirrors are made of silver-coated foils, which are bent into the correct shape by electrostatic charging. The solar illumination power entering a greenhouse unit via the mirrors is about 65 kW during the illumination phases. While this power is necessary to optimally facilitate photosynthesis, it would quickly overheat the greenhouse without an active cooling radiator. In our design, the cooling system operates with ammonia and water as working fluids. In this way, the temperature inside the greenhouse can be kept close to 26°C during the illumination phases.
(Source: ESA news release. Courtesy images)