TY - THES

T1 - Development of a conveying system for the moon

AU - Taschner, Andreas

N1 - no embargo

PY - 2021

Y1 - 2021

N2 - In recent years, space exploration missions to Mars and the Moon have become more attractive again. One reason for this is that it is possible to produce oxygen directly on the Moon using lunar resources. In-situ resource utilization (ISRU) aims to produce oxygen directly on the Moon using lunar resources without transporting resources from Earth to the Moon. It is the first step to enable independent life on the Moon. ISRU can be divided into four main stations: excavation, conveying, beneficiation, and processing. It is called the ISRU chain. The next goals in the future are to provide oxygen as fuel for rockets and to enable longer human space exploration missions. The conveyance of materials thus represents the second step of the entire ISRU chain. The unique and challenging environmental conditions and requirements, on the conveying system, lead to the fact that a conventional terrestrial conveying unit on the Moon does not work as desired. These environmental conditions and requirements include, for example, the thin atmosphere, the temperature fluctuations, the material to be conveyed (namely lunar regolith, abrasive and cohesive properties), and that the conveyor system must function completely autonomously since there are no humans on the Moon. Therefore, in the context of this work, a concept for a conveyor system is designed, which meets the challenging conditions of the Moon. Various different basic conveying principles are available that can build a functioning lunar conveyor. After examining the feasibility and comparing the advantages and disadvantages of each conveying principle, it was decided that a ballistic conveying system had the greatest potential to operate as a lunar conveyor. This system has crucial benefits: through the low gravity of the Moon, the conveying material flies over larger distances compared to the Earth, atmosphere resistance is low due to the thin atmosphere, and a flexible/mobile version of the conveyor is feasible. The ballistic conveyor is based on the functionality of a medieval ballista and is designed to be attached directly to the excavator, so no chassis is necessary. Before studying the conveying system in more detail, a first rough calculation is also made to theoretically estimate the maximum conveying distance. Furthermore, the ballistic conveyor system can be divided into three main assemblies: the machine loading system, the drive, and the swivel mechanism. The machine loading system is the interface between the excavator and the conveyor. It essentially consists of 2 industrial robots that transfer a total of 3 buckets, which are filled at the transfer chute of the excavator, between the transfer chute and the acceleration system, namely the drive. Furthermore, the drive ensures the acceleration of the material. The buckets are held by the drive, which pre-tensions springs that are then released and thus accelerate the bucket together with the material and finally abruptly decelerate the bucket so that the material flies to the desired destination. The swivel mechanism is responsible for the alignment and aiming of the conveyor unit. The target destination of the material is static and the conveyor is constantly in motion, so the drive must also be realigned in order to accelerate the material in the right direction. After working out the individual principles of the assemblies and how they work together, a 3D model of the conveyor system was created. The main focus here is on the mechanical setup and that the conveyor system is functioning. The 3D model is certainly not the highest level of detail and only the most important parts were detailed, such as the drive or the industrial robots. The reason for this is that other aspects have to be taken into account, such as topology optimization. Before this conveyor system can be used on the Moon, other aspects must also be worked out in more detail, such as the energy supply or the automation of the system. These further challenges should be solved in interdisciplinary teams to generate a promising output. The final conveying system presents a possible approach focusing on mechanical functionality. This system addresses the unique requirements of the lunar environment and presents basic mechanical concepts to overcome these requirements to enable lunar conveying, as well as providing opportunities for individual components to undergo further development and be used on other conveyors. Furthermore, this system can also be used for other tasks besides the transportation of material. Leveling the surface, transporting other materials besides lunar regolith, or using the industrial robots of the machine loading system for reparations and maintenance are some examples of other applications.

AB - In recent years, space exploration missions to Mars and the Moon have become more attractive again. One reason for this is that it is possible to produce oxygen directly on the Moon using lunar resources. In-situ resource utilization (ISRU) aims to produce oxygen directly on the Moon using lunar resources without transporting resources from Earth to the Moon. It is the first step to enable independent life on the Moon. ISRU can be divided into four main stations: excavation, conveying, beneficiation, and processing. It is called the ISRU chain. The next goals in the future are to provide oxygen as fuel for rockets and to enable longer human space exploration missions. The conveyance of materials thus represents the second step of the entire ISRU chain. The unique and challenging environmental conditions and requirements, on the conveying system, lead to the fact that a conventional terrestrial conveying unit on the Moon does not work as desired. These environmental conditions and requirements include, for example, the thin atmosphere, the temperature fluctuations, the material to be conveyed (namely lunar regolith, abrasive and cohesive properties), and that the conveyor system must function completely autonomously since there are no humans on the Moon. Therefore, in the context of this work, a concept for a conveyor system is designed, which meets the challenging conditions of the Moon. Various different basic conveying principles are available that can build a functioning lunar conveyor. After examining the feasibility and comparing the advantages and disadvantages of each conveying principle, it was decided that a ballistic conveying system had the greatest potential to operate as a lunar conveyor. This system has crucial benefits: through the low gravity of the Moon, the conveying material flies over larger distances compared to the Earth, atmosphere resistance is low due to the thin atmosphere, and a flexible/mobile version of the conveyor is feasible. The ballistic conveyor is based on the functionality of a medieval ballista and is designed to be attached directly to the excavator, so no chassis is necessary. Before studying the conveying system in more detail, a first rough calculation is also made to theoretically estimate the maximum conveying distance. Furthermore, the ballistic conveyor system can be divided into three main assemblies: the machine loading system, the drive, and the swivel mechanism. The machine loading system is the interface between the excavator and the conveyor. It essentially consists of 2 industrial robots that transfer a total of 3 buckets, which are filled at the transfer chute of the excavator, between the transfer chute and the acceleration system, namely the drive. Furthermore, the drive ensures the acceleration of the material. The buckets are held by the drive, which pre-tensions springs that are then released and thus accelerate the bucket together with the material and finally abruptly decelerate the bucket so that the material flies to the desired destination. The swivel mechanism is responsible for the alignment and aiming of the conveyor unit. The target destination of the material is static and the conveyor is constantly in motion, so the drive must also be realigned in order to accelerate the material in the right direction. After working out the individual principles of the assemblies and how they work together, a 3D model of the conveyor system was created. The main focus here is on the mechanical setup and that the conveyor system is functioning. The 3D model is certainly not the highest level of detail and only the most important parts were detailed, such as the drive or the industrial robots. The reason for this is that other aspects have to be taken into account, such as topology optimization. Before this conveyor system can be used on the Moon, other aspects must also be worked out in more detail, such as the energy supply or the automation of the system. These further challenges should be solved in interdisciplinary teams to generate a promising output. The final conveying system presents a possible approach focusing on mechanical functionality. This system addresses the unique requirements of the lunar environment and presents basic mechanical concepts to overcome these requirements to enable lunar conveying, as well as providing opportunities for individual components to undergo further development and be used on other conveyors. Furthermore, this system can also be used for other tasks besides the transportation of material. Leveling the surface, transporting other materials besides lunar regolith, or using the industrial robots of the machine loading system for reparations and maintenance are some examples of other applications.

KW - Weltraumbergbau

KW - Fördertechnik im Weltraum

KW - Ressourcennutzung vor Ort

KW - Regolith

KW - Space mining

KW - Space conveying

KW - ISRU

KW - Regolith

M3 - Master's Thesis

ER -