2020-07-292020-07-292020-07-31ICES_2020_210https://hdl.handle.net/2346/86396Emile Haddad, MPB Communications Inc., CanadaRoman Kruzelecky, MPB Communications Inc., CanadaPiotr Murzionak, MPB Communications Inc., CanadaKamel Tagziria, MPB Communications Inc., CanadaIan Sinclair, MPB Communications Inc., CanadaGregory Schinn, MPB Communications Inc., CanadaBoris Le Drogoff, INRS EMT, CanadaChaker Mohamed, INRS EMT, CanadaJean-Francois Thibaultl, Magellan Aerospace, CanadaPaul Burbulea, MPB Communications Inc., CanadaEric Choi, Magellan Aerospace, CanadaThe proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.MPB, with INRS and Magellan Aerospace, have advanced the performance of its thin-film smart radiator device (SRD) for the passive thermal control of space structures. These are based on the tailored semiconductor/insulator transition of nano-engineered Vanadium Dioxide (VO2) as deposited by laser ablation or reactive sputtering on thin aluminum substrates. Currently, the tiles are 4cm x 4cm in area. Thermal radiators of arbitrary area can be provided by attaching the tiles to a common radiator panel using a suitable thermal epoxy. Thermal emittance values were estimated from IR Fourier transform measurements of the sample reflectance between 2.5 and 25 µm. Typically, an emittance tuneability (Δε) of about 0.4 is achieved, varying from ε-low < 0.36 at temperatures below the transition temperature, to ε-high > 0.76 above the transition temperature. The SRD tiles passively reduce heat loss from a space structure at lower temperatures, while providing for enhanced thermal exchange to dark space at higher temperatures to moderate the net temperature variation. With no mechanical moving components, reliable long-term performance is anticipated. Relatively extensive ground verifications have included testing of the thermal switching under vacuum conditions, vibration testing of Al radiators based on an assembly of the tiles, and relevant radiation testing relevant to use in a geostationary (GEO) orbit environment. The SRD performance has been validated in an LN2-cooled thermal vacuum chamber using different heat loads for SRD temperatures between -60oC and +80oC. In comparison to the case of a fixed-emissivity radiator, a much lower overall temperature variation of the system is possible using the passively-tuned SRD radiator. A flight demonstration of the SRD technology is planned for an upcoming launch of a Kepler Communications spacecraft. This paper discusses the technology advancement and ground qualification of the SRD components to be validated in a low Earth Orbit (LEO) space environment.application/pdfengSmart Thermal RadiatorSRDPassive Thermal ControlSemiconductor/insulator TransitionThermal EmittanceEmittance TuneabilityPresentation