Building on Mars

Abstract

Throughout the time humans have always looked up to starry skies and wondered about travelling to the stars. With the current developments in the aerospace field, travelling to neighboring planets have never been more possible. On the top of the agendas of numerous organizations today is the exploration of the Red Planet. However, there are many factors that complicate travelling to and building habitats on Mars. First and foremost constraint is the fragile human health that can not withstand the biological effects of ionizing space radiation. Following is the costliness and difficulty of carrying materials to Mars in hopes for building habitations. Last but not the least, the 22 minutes transmission delay between Earth and Mars, which makes it impossible to run and control operations on Mars surface in real time, and arises the necessity that majority of the operations has to run autonomously. All these limitations brings about one question that this thesis tries to answer; how to autonomously construct a radiation shielding habitat on Mars.
In order to come up with a methodology, it was necessary to take a step back and start the project from selecting a mission among those defined in DRA 5.0 by NASA, as the mission characteristics limit the construction tools and methods for building on Mars. After mission details are set and landing site is chosen, the study started defining the construction methodology by choosing the appropriate material for radiation shielding. This material, water, is the core to the construction of the habitation and due to transportation limitations, in-situ materials on the Martian surface were evaluated. The regolith, in other words the Martian soil, and water were two potential candidates due to their presence on the surface. Water was chosen as a better shield for space radiation due to its highly hydrogenated structure. The water on Mars is encapsulated in four types of reserves; regolith, glacier ice, poly-hydrated sulfate minerals, and phyllosilicate minerals. Without rover missions and on-site data collection, it is not possible to confirm the presence of the remaining three reserves except from regolith at the landing site. Therefore, regolith was selected as the main reserve for water extraction, which brought about the question of energy requirements for such a process. Two possible energy generation systems including solar and fission power were then analysed, and a simultaneous use of both was deemed to be the most beneficial approach. Although fission power systems work with high efficiency, this type of generators can not be the sole source of energy due to their biological effects on human health and must be positioned at least a kilometer away from the habitat. In order to protect the crew, the solar energy systems that provide clean energy is selected to support the habitation while the fission powered systems are firstly tasked with generating energy for the return vehicles, then to the habitat from a far distance. After all these details on material selection, extraction and energy generation are determined, the project moved on to the construction steps.
The construction process starts when one inflatable habitat module, which is pre-manufactured on Earth, is sent to the surface of Mars. The envelope around the module consists of water/ice bags that will then be filled with the water, extracted from the regolith, via a robotic arm. The water has been ISRU derived by processing the regolith with microwave technologies, which was deemed as the most efficient way of extracting water from regolith. In order to transport regolith to the ISRU plants 4 rassors will employed. These rassors will also play a vital role in the previous construction steps.
At the end of this autonomous construction, the habitat is planned to accommodate a crew of six, for 539 days on the surface of the Mars. The habitat was designed with an aim of keeping the crew members’ total equivalent dose of radiation exposure within 0.40-0.50 Sievert range inside the habitat.