Simultaneous Harvesting of Incoming Solar and Outgoing Thermal Radiation in a Space Environment

TECH FOCUS AREAS: Network Command, Control and Communications TECHNOLOGY AREAS: Sensors OBJECTIVE: The objective of this topic is to develop technologies that enable harvesting of outgoing thermal radiation to generate useful work. Moreover, the incoming sunlight and outgoing thermal radiation typically occupy different spectral wavelength ranges. The sunlight is in the wavelength range spanning from approximately 2 micron to ultraviolet, whereas the thermal radiation is in the longer wavelength range. Therefore, it is conceivable that both solar and thermal radiation can be harvested using the same device in different operation modes, leading to the capability of simultaneous harvesting. Being able to do so could enhance the power generation capability of a spacecraft without increasing its weight. DESCRIPTION: In a space environment the thermal balance of a spacecraft is dominated by radiations. These radiations include sunlight as well as the thermal radiation. To control the thermal balance of a spacecraft it is therefore of crucial importance to control the solar absorption and the thermal emission properties. Moreover, both the process of the absorption of sunlight and the emission of thermal radiation can be harvested to generate useful work such as electricity. However, while significant work has focused on developing high-efficiency photovoltaic cells for harvesting sunlight, far less work has been devoted to developing device that can harvest the outgoing thermal radiations. PHASE I: Phase I of the project will explore the feasible device concepts and elucidate the theoretical and practical limits of simultaneous energy harvesting PHASE II: Phase II of the project will demonstrate a viable scheme for simultaneous harvesting with generated power density exceeding that of a standard photovoltaic cell for the same physical area. PHASE III DUAL USE APPLICATIONS: The fundamental nature of AFOSR programs reflect the broad opportunity to commercialize science to both commercial and defense markets. Awardees will have the opportunity to integrate with prospective follow-on transition partners. The contractor will transition the solution to provide expanded mission capability to a broad range of potential Government and civilian users and alternate mission applications. REFERENCES: 1. 2018 National Defense Strategy of the United States Summary. Retrieved from: https://www.Defense.gov/Portals/1/Documents/pubs/2018-National-Defense-Strategy-Summary.pdf