UCLA

Space exploration is of paramount importance to advancing fundamental science, such as understanding the formation of universe and origins of life, as well as for the global economy, including communications and navigation. Despite the many milestones that we’ve witnessed in the last 60 years of space exploration, today’s space exploration is hindered by the limitations of existing spacecraft propulsion technologies. Specifically, limited acceleration and velocity gain constrain the range of possible orbital maneuvers and challenge visionary deep space missions. In this thesis, we examine the use of radiation pressure for fast in-space propulsion. We show that minute forces of radiation pressure may be utilized to accelerating spacecraft to speeds that surpass those attainable by conventional chemical rockets and electric engines. Agile and fast-transit Earth orbital maneuvering and fast-flyby solar system exploration missions are discussed. Two distinct approaches to light-driven space exploration are examined. Lightsailing that makes use of laser beams is shown to be advantageous for Earth orbital transfers and for missions to outer planets with small <10 g payloads. Solar sails provide an alternative for outer planet and interstellar space exploration. By sending ultralight solar sails close to the sun, solar-sail spacecraft can be accelerated to very high velocities. Both approaches face a number of technical and materials challenges, some of which are studied in this thesis. One of the key objectives of this dissertation is to design and fabricate suitable materials for such high speed light-driven propulsion approaches. We use a combination of analytical, computational, and experimental methods. Starting with space mission concept of operations analysis and examining related parameter tradeoffs, we provide guidelines that drive computational and experimental research of this thesis. Both analytical and computational methods are used to photonic materials that meet stringent mission requirements. A novel fabrication process is developed to prototype sail materials designed theoretically. Fabricated samples are measured and characterized, and their performance is examined. Lastly, possible space environmental effects associated with solar sailing in the close proximity to the sun are discussed and analyzed. This work aims at laying a foundation for the design of materials based on nanophotonic engineering for future light-driven in-space propulsion.