Architekt Thomas Herzig | Weyringergasse 29/ 17, 1040 Vienna, Austria | +43 699 11101220 | firstname.lastname@example.org
Short Description: ESA-funded moon habitat concept featuring an ultra-light inflatable membrane structure covered by lunar regolith for protection. Mirrors reflect visible sunlight into toroidal greenhouses for self-sufficient production of food and oxygen, while cosmic particle radiation is kept out. This disruptive design can revolutionize space exploration and sustainability.
This design study was funded by the European Space agency in 2022. The moon habitat consists of an ultra-light inflatable membrane structure that is carefully manufactured and tested on Earth to ensure quality and durability All other building material comes from the lunar surface as loose regolith, which will be deposited on top of the inflatable structure in order to protect from cold, radiation and meteorites .
Since there is no atmosphere on the Moon, an inflatable structure inflated up to half Earth-atmospheric pressure (or 500 millibar= 50KN/m2) could support a deposit of regolith up to 16 meters high on the Moon. However, 4 meters of deposit are sufficient for protection. Since the interior air pressure has a lot more effect on the building structure than the weight of the deposit, rigid (3D- printed) walls and ceilings are unnecessary to hold the structure.
The centerpiece of our design are the toroidal greenhouses, where oxygen, water and food are self-sufficiently produced and recycled. All other rooms are linked to these greenhouses. Our design enables natural sunlight to enter the greenhouses, while cosmic particle radiation is blocked out.
At the lunar poles the sunlight comes almost horizontally but from different directions. Viewed from that location, the Sun cycles around the horizon every 29 days.
The greenhouse features a toroidal shape and features an open crater in the center. A rotating mirror reflects the horizontally arriving sunlight down into the crater, from where it is reflected again by a nearly cone-shaped mirror into the toroidal greenhouse.
Thus, inside we create a natural environment, where plants, microorganisms, animals and humans live in symbiosis,
We need a structure that holds and rotates the mirror to reflect the sunlight down into the greenhouse crater. Since the sunlight arrives in an almost horizontal angle annually changing between -1,5° and + 1,5°, the mirror needs to be inclined by approximately 45° and annually change its vertical angle by +/- 0,75°.
To keep the weight and volume of payload low, the mirror consists of a ripstop Kapton membrane with a reflective silver coating. The silver coating reflects less of the UV-radiation but a bit more of the visible radiation range compared to a more common aluminum coating. So, finally the range of solar-radiation that reaches the greenhouse is very close to of what reaches Earth´s surface after being filtered through the atmosphere.
The size of that oval mirror membrane is 9,2 x 13 meters. To get a smooth, slightly concave surface, the membrane needs to be statically prestressed. Since the mirror and its supportive structure are exposed to micro-meteorite bombardment, we excluded the option of vulnerable inflatable components, that could deflate .
The mirror membrane plus another parallel membrane are spanned inside an oval truss frame ring made of carbon fiber tubes. Both membranes are electrostatically charged, to attract each other and bend towards each other. With the applied voltage it can be adjusted, how much these two membranes are bent into a parabolic shape to specify its focal point. Micro-meteorites still can puncture the membrane, but that does not significantly affect the functionality of the mirror.
The hyperbolic supporting structure is the lightest and most efficient geometry for that purpose. CFRP-tubes form a diagonal grid that again forms a hyperbolic cylinder. It is a special feature of the hyperbolic cylinder among all rotational bodies, that is formed by slanted straight lines.
The whole structure can be folded together into a very slim compact cylinder for transportation. All CFRP tubes are fixed at one end on an inflatable hyperbolic form. When this hyperbolic form is inflated, the tubes are automatically brought into the right position. After they are fixed at their connection points, the inflatable form can be removed.
Then an oval ring is connected to the tubes´ ends on top and a circular ring at the bottom. These rings are divided into several modular parts, that are small enough to fit into the payload bay of the chosen spaceship, but large enough to keep the number of parts and the effort for the assembly as low as possible.
The circular rail, which is the base for the mirror-tower, is magnetic, so there are no wheels where Moon dust could enter the bearings. Also, the magnets can function as a linear motor to rotate the mirror.