# Concept of a 3D-Printed Voronoi Egg-Shaped Habitat for Permanent Lunar Outpost
## 4 Results  
To create the concept of 3D-printed habitat for a permanent lunar outpost, only one egg-shaped habitat with an entrance and external lighting solution was considered (see Figures 8-12). It uses an existing crater into which the habitat is embedded to a third or half of its height. The entire complex is covered with regolith. Thanks to this, the problem of access during construction will be minimized and the resulting embankment will not be large. However, a large number of cubic meters of material still needs to be moved. The  
Figure 7: A view of a Lunar habitat construction procedure divided into six phases (**A**–**F**).  
design envisages a 3D-printed main structure of the habitat, including a paved access area with a retaining wall preventing regolith from sliding to the entrance of the facility. This solution shortens the required length between the entrance and the habitat. At the same time, it is possible to transfer material more easily on a reinforced (by spatial 3D-printed geopolymer) surface, or to partially use it for storage. Additional modifications can be made for this purpose. In the connection between the exterior and the habitat, there is a pressure chamber and a changing room with stored spacesuits. This is the only element of the proposed lunar outpost which will not be 3D-printed.  
The 3D-printed egg habitat is 13.5 m in diameter and 18 m high, so that the minimum clear height of one floor is 3.5 m. Due to the low gravity (one sixth of the Earth's gravity), it is possible to use equipment with a larger height preventing possible injuries when moving in inside. The main element of the design is an adjustable mirror at the top of the entire structure. It reflects sunlight into a vertical tube that permeates through all floors. Thanks to reflective surfaces and optical guidance, it transmits the light to all rooms, especially to the floors where plants are grown. The mirror makes it possible to regulate the amount of light and radiation that enters the habitat and (if necessary) it is possible to completely block the light inlet. Therefore, simulating the 24 h day-night cycle is enabled. This property is essential for the well-being of astronauts, due to the location of the outpost at the lunar South Pole. The sun is low on the horizon there, but it never sets. The light tube also serves as a communication hub across the individual floors. If larger pieces of material need to be moved, the folding part of the floor can be used for this purpose. However, there is a need to assess the effectiveness and safety of the communication method through this tube, precisely because of the concentration of reflected sunlight through the mirror.  
Figure 8: Cross-sectional view of the final variant of one egg-shaped habitat, semi-submerged to an existing crater with a piled-up regolith.  
Figure 10: A view of a 3D section in the perspective of a semi-submerged habitat.  
Figure 9: View of the complex with the entrance from the outside.  
Figure 11: Perspective view of the first floor (command floor) of the habitat. A light tube can be seen in the image.  
Figure 12: Perspective view of the third underground floor (greenhouse and laboratories) of the habitat.  
The first underground floor is almost flushed with the external access area for easy movement. This floor also serves as a command and operations planning floor.  
The second underground floor is dedicated to the crew as accommodation, dining room, gym, and relaxation room. It is clear that it will need to be divided into individual sections with movable partitions for greater privacy.  
The third underground floor serves as a greenhouse and laboratories.  
The last (fourth) floor is for storing supplies, technical equipment, and containers for oxygen, water, and others.