Augmented reality in a planetary greenhouse for crew time optimization

Abstract

The Artemis campaign aims to return humans to the Moon by the late 2020s, nearly 50 years after the last Apollo astronauts walked on the lunar surface. As a precursor for missions to Mars, long-term and self-sustaining habitats are planned to be deployed on the Moon by the mid-2030s. A vital element of these habitat infrastructures will be planetary surface greenhouses capable of producing fresh food and recycling the habitat's air and water, reducing the need for (re-)supplies from Earth. Furthermore, plant cultivation benefits the crew's psychological well-being during space missions. For these reasons, several space agencies (e.g., ASI, CSA, DLR, and NASA) are investigating planetary surface greenhouses for bioregenerative life support. Research has shown that crew time is a valuable but limited resource during space travel and that the mission's success depends on the proper allocation of crew time. Therefore, crew time must also be optimized for operations of planetary surface greenhouses, especially to dedicate sufficient time for scientific activities. Furthermore, the perceived workload of planetary surface greenhouse operators (astronauts) must be reduced as much as possible. To accurately estimate the crew time and workload required for greenhouse operations, engineers and mission planners rely on the data gathered from space analog facilities and space station plant experiments. However, past research has shown a paucity of comparative crew time and workload data. Furthermore, existing crew time datasets are difficult to compare as no standardized measurement approaches exist. In this thesis, investigations were conducted to determine how workload and crew time could be optimized for the operations of planetary surface greenhouses. The first part of the thesis investigated two space research-related questions: (RQ1) How can crew time measurements be standardized for better comparability? and (RQ2) How much crew time and workload are required in a space greenhouse? In response to these research questions, the investigations in the first part of this thesis resulted in four key contributions: (C1) Databases of crew time and workload values for space greenhouse operations have been created, (C2) Conclusions were drawn about what factors affect crew time and how their characteristics differ for greenhouses used in various space mission scenarios, (C3) Recommendations were made on which of the tasks/procedures studied should be simplified, automated, or remotely supported to reduce the workload of space greenhouse operators, and (C4) Methodologies were developed to standardize the crew time measurements for on-site operator activities in space greenhouses and associated remote support activities. Two new research questions emerged from these results: (RQ3) What features should be integrated into an augmented reality interface used in a space greenhouse to facilitate workflows for on-site operators and remote support teams on Earth? and (RQ4) How should immersive technologies such as augmented reality interfaces be designed and developed to reduce the crew time and workload of astronauts and remote support teams on Earth when operating a space greenhouse? An interdisciplinary approach was chosen to address these research questions arising from the challenges of space exploration. The importance of augmented reality for workflow optimization has increased in recent years in various application areas. For this reason, the second part of this thesis focused on computer science-related investigations for implementing augmented reality in planetary surface greenhouses to optimize workload and crew time. Investigations outlined in this part resulted in four key contributions to the research field: (C5) A conceptual design of an augmented reality interface for a planetary surface greenhouse was presented, (C6) A new tool for real-time plant detection and augmentation running directly on an augmented reality headset was developed, (C7) A novel and relatively simple approach was developed for in situ generation and visualization of plant health (plant stress) information on an augmented reality headset for use in space greenhouses, and (C8) The benefits and relevance of augmented reality applications for the design, optimization, and operations of greenhouses used during space missions were demonstrated. Overall, the values and research on crew time, workload, and utilization of augmented reality applications presented in this thesis have significant implications for the design and operations of future planetary surface greenhouses and the planning of related space missions. These results can equally improve the reliability and efficiency of operations in today's terrestrial food production systems, such as greenhouses and vertical farms, making the findings immediately applicable and relevant on Earth. While the findings have expanded the limited research on operations and augmented reality applications for planetary surface greenhouses, additional research is still needed.