Browsing by Author "Haddad, Emile"
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Item Lunar Dust Mitigation for the Potential LORE Science Payload(44th International Conference on Environmental Systems, 2014-07-13) Kruzelecky, Roman V.; Aïssa, Brahim; Lavoie, Jonathan; Haddad, Emile; Jamroz, Wes; Cloutis, Edward; Therriault, DanielThis paper considers the lunar dust mitigation requirements of the potential LORE Lunar Origins and Resource Explorer science payload as part of the robotic Lunar Soil Mechanics Investigation System (LSM) subsurface geophysics package on the Selene-2 lander. This includes cleaning the LORE bore- hole fiber-optic Probe between the analysis of different bore-holes near the lander to minimize cross- contamination effects. A multilevel dust shield incorporating Carbon nanotube (CNT) technologies is considered to meet the various LORE dust protection requirements. Indeed, adding CNT could improve both the electrical conductivity of the trapping material to improve the deflection capability, and its porosity toward the trapping of submicron particles size. To improve the study of the effects of planetary dust on optics and mechanical assemblies, two new simulants, namely UW-1M and UW-1H, have been developed that can provide a relatively high fidelity overall simulation of the relevant effects of lunar mare and highland dust (nanophase Fe, size distribution, mechanical wear, optical spectral absorptance, magnetic properties, etc.). Preliminary test results for the CNT magneto-electrostatic dust deflectors/filters are presented and the results discussed.Item VO2-based Thin-Film Smart Radiator Device for improved Passive Thermal Control of Space Systems(2020 International Conference on Environmental Systems, 2020-07-31) Haddad, Emile; Kruzelecky, Roman; Murzionak, Piotr; Tagziria, Kamel; Sinclair, Ian; Schinn, Gregory; Le Drogoff, Boris; Mohammed, Chaker; Thibault, Jean-Francois; Burbulea, Paul; Choi, EricMPB, 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.