References of "Rochus, Pierre"
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See detailConception of a near-IR spectrometer for ground-based observations of massive stars
Kintziger, Christian ULg; Desselle, Richard ULg; Loicq, Jerôme ULg et al

Poster (2016, June 27)

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships ... [more ▼]

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships from the scientific requirements and telescope characteristics, the entire optical design of the spectrograph is presented. Specific optical elements, such as a toroidal lens, are introduced to improve the instrument’s performances. Then, the verification of predicted optical performances is investigated through optical analyses such as resolution checking. Eventually, the star positioning system onto the central fiber core is explained. [less ▲]

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See detailConception of a near-IR spectrometer for ground-based observations of massive stars
Kintziger, Christian ULg; Desselle, Richard ULg; Loicq, Jerôme ULg et al

in Proc. SPIE Volume 9908 Ground-based and Airborne Instrumentation for Astronomy VI (2016)

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships ... [more ▼]

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships from the scientific requirements and telescope characteristics, the entire optical design of the spectrograph is presented. Specific optical elements, such as a toroidal lens, are introduced to improve the instrument’s performances. Then, the verification of predicted optical performances is investigated through optical analyses such as resolution checking. Eventually, the star positioning system onto the central fiber core is explained. [less ▲]

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See detailReal-time measurement of temperature variation during nanosecond pulsed laser induced contamination deposition
Kokkinos, Dimitrios ULg; Gailly, Patrick ULg; Georges, Marc ULg et al

in Applied Optics (2015), 54(36), 10579

In this paper a study of the heat generation during UV Laser Induced Contamination (LIC) and potentially resulting subsequent thermal damage is presented. This becomes increasingly interesting when optics ... [more ▼]

In this paper a study of the heat generation during UV Laser Induced Contamination (LIC) and potentially resulting subsequent thermal damage is presented. This becomes increasingly interesting when optics with delicate coatings are involved. During LIC radiation can interact with outgassing molecules both in the gas phase and at the surface, triggering chemical and photo-fixation reactions. This is a major hazard, in particular for laser units operating under vacuum conditions such as for space applications. The intense photon flux not only affects the contaminant deposition rate but also alters their chemical structure that can increase their absorption coefficient. Over cumulative irradiation shots these molecules formed deposits that increasingly absorb photons and produce heat as a by-product of de-excitation eventually leading to thermal damage. One could better asses the risk of the latter with the knowledge of temperature during the contamination process. For this purpose thermoreflectance technique is used here to estimate the temperature variation from pulse to pulse during contamination deposition through the analysis of a temperature-dependent surface reflectance signal. [less ▲]

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See detailSURFACE ENGINEERING FOR PARTS MADE BY ADDITIVE MANUFACTURING
Nutal, Nicolas; Rochus, Pierre ULg; Collette, Jean-Paul et al

in 66th International Astronautical Congress (2015, October)

the surface preparation of metal parts made by additive manufacturing (AM). AM is a technology of choice for manufacturing of parts with complex shapes (heat exchangers, RF supports, optical parts…) and ... [more ▼]

the surface preparation of metal parts made by additive manufacturing (AM). AM is a technology of choice for manufacturing of parts with complex shapes (heat exchangers, RF supports, optical parts…) and integrated functions such as conformal cooling channels, clips, hinges, etc. This opens the door for lightweight parts which are of prime importance for space applications. The potential of the AM technologies is however impeded by the quite rough surface finish that is observed on the as-manufactured parts. It is known that such a finish is likely to impact the performance of the parts. Several post-treatment techniques can be applied to improve the surface condition of the AM parts. However, so far, the influence of the successive post-processing steps on the final properties is not well established. Therefore, a better understanding of the impact of surface characteristics on the material behaviour is needed to expand the use of AM for high performance parts. The objective of this study, supported by ESA, is to propose and evaluate various surface finishing techniques for parts made by the AM technologies, in order to check their compatibility, evaluate their properties and derive guidelines for future applications. CRM is the prime proposer of this study and is in charge of the surface treatment and characterisations. Sirris additive manufacturing facilities are used to produce the parts. Thales Alenia Space and Walopt are included into the industrial team to provide concrete application cases. The study focuses on metals. Two metals under study are presented here: AlSi10Mg and Ti6Al4V. This paper is devoted to the early results of the first steps of surface preparation, namely material removal from the surface of the produced parts in order to improve their surface properties. As a first phase, tribo-finishing (TF) is tested on prototype parts to check its capabilities. Surface and volume parameters are analyzed, namely achieved roughness, material removal rate, location of removed material. The limitations in terms of geometry and applicability are discussed as well. These first observations should serve as guidelines for further application of AM for the design of parts used in space industry. [less ▲]

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See detail"Additive Layer Manufacturing for Space Instrumentation and subsystems"
Rochus, Pierre ULg

Conference (2015, August 22)

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See detailThermal Balance Test of Solar Orbiter EUI Instrument Structural and Thermal Model with 13 Solar Constants
Jacques, Lionel ULg; Halain, Jean-Philippe ULg; Rossi, Laurence ULg et al

Scientific conference (2015, March 26)

Developed by a European consortium led by the Centre Spatial de Liège in Belgium, the Extreme Ultraviolet Imager (EUI) is an instrument onboard the Solar Orbiter ESA M-class mission. At its 0.28AU ... [more ▼]

Developed by a European consortium led by the Centre Spatial de Liège in Belgium, the Extreme Ultraviolet Imager (EUI) is an instrument onboard the Solar Orbiter ESA M-class mission. At its 0.28AU perihelion, the spacecraft will be exposed to a 13 solar constants solar flux. EUI is protected behind the spacecraft heat shield but for three apertures for its telescopes looking at the Sun in the Extreme-UV. To better reject the unwanted visible light and protect 150nm thick EUV filters, Aluminum coated carbon-fiber-reinforced plastics entrance baffles are located at the front of the instrument. The residual absorbed heat by the entrance filters and baffles is evacuated through heat pipes to a dedicated spacecraft thermal interface. To verify its thermal design, the instrument structural and thermal model has been tested in a vacuum chamber with a solar simulator providing the 13 solar constants solar flux at the three entrance apertures and dedicated heaters to model the spacecraft heat shield feedthroughs. To assess the off-pointing performance of the entrance baffles, the instrument was mounted onto a rotating structure inside the chamber. The test setup, results and the thermal model correlation will be presented as well as the calibration of the solar simulator divergence and intensity. [less ▲]

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See detailThe extreme UV imager telescope on-board the Solar Orbiter mission: overview of phase C and D
Halain, Jean-Philippe ULg; Rochus, Pierre ULg; Renotte, Etienne ULg et al

in SPIE Optical Engineering+ Applications (2015)

The Solar Orbiter mission is composed of ten scientific instruments dedicated to the observation of the Sun’s atmosphere and its heliosphere, taking advantage of an out-of ecliptic orbit and at perihelion ... [more ▼]

The Solar Orbiter mission is composed of ten scientific instruments dedicated to the observation of the Sun’s atmosphere and its heliosphere, taking advantage of an out-of ecliptic orbit and at perihelion reaching a proximity close to 0.28 A.U. On board Solar Orbiter, the Extreme Ultraviolet Imager (EUI) will provide full-Sun image sequences of the solar corona in the extreme ultraviolet (17.1 nm and 30.4 nm), and high-resolution image sequences of the solar disk in the extreme ultraviolet (17.1 nm) and in the vacuum ultraviolet (121.6 nm). The EUI concept uses heritage from previous similar extreme ultraviolet instrument. Additional constraints from the specific orbit (thermal and radiation environment, limited telemetry download) however required dedicated technologies to achieve the scientific objectives of the mission. The development phase C of the instrument and its sub-systems has been successfully completed, including thermo-mechanical and electrical design validations with the Structural Thermal Model (STM) and the Engineering Model (EM). The instrument STM and EM units have been integrated on the respective spacecraft models and will undergo the system level tests. In parallel, the Phase D has been started with the sub-system qualifications and the flight parts manufacturing. The next steps of the EUI development will be the instrument Qualification Model (QM) integration and qualification tests. The Flight Model (FM) instrument activities will then follow with the acceptance tests and calibration campaigns. [less ▲]

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See detailThe extreme ultraviolet imager of solar orbiter: optical design and alignment scheme
Halain, Jean-Philippe ULg; Mazzoli, Alexandra ULg; Meining, S. et al

in SPIE Optical Engineering+ Applications (2015)

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See detailImportance of structural damping in the dynamic analysis of compliant deployable structures
Dewalque, Florence ULg; Rochus, Pierre ULg; Bruls, Olivier ULg

in Acta Astronautica (2015), 111

Compliant mechanisms such as tape springs are often used on satellites to deploy appendices, e.g. solar panels, antennas, telescopes and solar sails. Their main advantage comes from the fact that their ... [more ▼]

Compliant mechanisms such as tape springs are often used on satellites to deploy appendices, e.g. solar panels, antennas, telescopes and solar sails. Their main advantage comes from the fact that their motion results from the elastic deformation of structural components, unlike usual hinges or prismatic joints, the motion of which is dictated by contact surfaces. No actuators or external energy sources are required and the deployment is purely passive, which appears as a decisive feature for the design of low-cost missions with small satellites or cubesats. The mechanical behaviour of a tape spring is intrinsically complex and nonlinear involving buckling, hysteresis and self-locking phenomena. High-fidelity mechanical models are then needed to get a detailed understanding of the deployment process, improve the design and predict the actual behaviour in the space 0-g environment. In the majority of the previous works, dynamic simulations were performed without any physical representation of the structural damping. These simulations could be successfully achieved because of the presence of numerical damping in the transient solver. However, in this case, the dynamic response turns out to be quite sensitive to the amount of numerical dissipation, so that the predictive capabilities of the model are questionable. In this work based on numerical case studies, we show that the dynamic simulation of a tape spring can be made less sensitive to numerical parameters when the structural dissipation is taken into account. [less ▲]

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See detail"Advanced Manufacturing Methods for Systems of Nanospacecrafts".
Rochus, Pierre ULg

Conference (2014, October 29)

Space instrumentation and Space Environmental testing activities at CSL Dreams, a priori expectations and space specificities Advanced Manufacturing Techniques considered in our studies First steps ... [more ▼]

Space instrumentation and Space Environmental testing activities at CSL Dreams, a priori expectations and space specificities Advanced Manufacturing Techniques considered in our studies First steps realizations 15 years ago More concrete and more recent examples Conclusions and future activities [less ▲]

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See detailNew applications of Advanced Manufacturing Methods for space instrumentation and Systems of Nanospacecraft
Rochus, Pierre ULg; Plesseria, Jean-Yves ULg; Corbelli, Alberto et al

Conference (2014, October 03)

In the frame of an ESA TRP project, our consortium has investigated the possibility to use advanced manufacturing methods for application to space hardware. After a review of the state of the art of the ... [more ▼]

In the frame of an ESA TRP project, our consortium has investigated the possibility to use advanced manufacturing methods for application to space hardware. After a review of the state of the art of the new manufacturing methods, including additive manufacturing but also advanced bonding, joining and shaping techniques, several case studies have been realized. These new techniques imply a different approach already at the design phase since the manufacturing constraints can be completely different. The goal of the project was to evaluate the different technologies from the design to the realization and learn how the classical design and development of such parts shall be adapted to take into account the different specificities of the new techniques. Three types of case studies have been developed successively. The first type was a re-manufacture of an existing piece of hardware using advanced techniques to evaluate if there is some potential improvement to be achieved (cost, production time, complexity reduction). The second level was to design and manufacture a part based on the application requirements. The last level was to design and manufacture a part taking into account in addition the subsystem to which it belongs. All case studies have been tested in terms of achieved performances and resistance to the mechanical and thermal environment. For each level, several case studies were proposed by ALMASpace and TAS-F and a pre-selection was performed to verify the feasibility and the interest of the proposed part for the project. For the first 2 levels, the 2 selected case studies have been designed, built and tested. A single case study was built for last level. The cases studies of level one were an aluminium inertial wheel housing (using electron beam welding to connect simple machined parts) and a mechanism housing fully made by additive manufacturing (electron beam melting of Titanium). The ones of level two were an aluminium tray for nanosatellite structure (assembled by salt dip brazing) and an antenna support bracket (designed by topological optimization and manufactured by laser beam melting of aluminium). The third level case study is a Sun Sensor for nanosatellite designed by topological optimization and including electronic circuit (optical detector and proximity electronic) deposited by aerosol jet printing directly on the aluminium structure. All case studies have been manufactured and tested and all part manufactured, despite including some imperfections, fulfilled all performance requirements. [less ▲]

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See detailNew Monolithic High Solar Rejection EUV Transmission Filter
Fleury-Frenette, Karl ULg; Renotte, Etienne ULg; Lenaerts, Cedric ULg et al

Conference (2014, August)

New Monolithic High Solar Rejection EUV Transmission Filter Fleury-Frenette, Karl; Renotte, Etienne; Lenaerts, C.; Rossi, Laurence; Jacques, Lionel; Halain, Jean-Philippe; Rochus, Pierre 40th COSPAR ... [more ▼]

New Monolithic High Solar Rejection EUV Transmission Filter Fleury-Frenette, Karl; Renotte, Etienne; Lenaerts, C.; Rossi, Laurence; Jacques, Lionel; Halain, Jean-Philippe; Rochus, Pierre 40th COSPAR Scientific Assembly. Held 2-10 August 2014, in Moscow, Russia, Abstract D2.3-22-14. A new high solar rejection transmission filter for the extreme UV has been developed for the Solar Orbiter Extreme Ultraviolet Imager (EUI). To provide enhanced resilience to high thermal load, a monolithic architecture approach has been taken in order to limit the thermal contact resistance between the filtering sub-micron thin film, its supporting mesh, and holding frame. Some aspects of the manufacturing process involving thin film deposition and photolithography will be presented along with optical performance and space environmental test results. New avenues for improving the thermo-optical properties of the filter will also be discussed. [less ▲]

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See detailSolar simulation test up to 13 solar constants for the thermal balance of the Solar Orbiter EUI instrument
Rossi, Laurence ULg; zhukova, Maria; Jacques, Lionel ULg et al

in Proceedings of SPIE (2014, June 18)

Solar Orbiter EUI instrument was submitted to a high solar flux to correlate the thermal model of the instrument. EUI, the Extreme Ultraviolet Imager, is developed by a European consortium led by the ... [more ▼]

Solar Orbiter EUI instrument was submitted to a high solar flux to correlate the thermal model of the instrument. EUI, the Extreme Ultraviolet Imager, is developed by a European consortium led by the Centre Spatial de Liège for the Solar Orbiter ESA M-class mission. The solar flux that it shall have to withstand will be as high as 13 solar constants when the spacecraft reaches its 0.28AU perihelion. It is essential to verify the thermal design of the instrument, especially the heat evacuation property and to assess the thermo-mechanical behavior of the instrument when submitted to high thermal load. Therefore, a thermal balance test under 13 solar constants was performed on the first model of EUI, the Structural and Thermal Model. The optical analyses and experiments performed to characterize accurately the thermal and divergence parameters of the flux are presented; the set-up of the test, and the correlation with the thermal model performed to deduce the unknown thermal parameters of the instrument and assess its temperature profile under real flight conditions are also presented. [less ▲]

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See detailADVANCED MANUFACTURING METHODS FOR SYSTEMS OF MICROSYSTEM NANOSPACECRAFT – STATUS OF THE PROJECT
Rochus, Pierre ULg; Plesseria, Jean-Yves ULg; Corbelli, Alberto et al

Conference (2014, April 04)

In the frame of an ESA TRP project, CSL, SIRRIS, ALMASpace and TAS-F associated to evaluate advanced manufacturing methods for application to space hardware. The state of the art of the new manufacturing ... [more ▼]

In the frame of an ESA TRP project, CSL, SIRRIS, ALMASpace and TAS-F associated to evaluate advanced manufacturing methods for application to space hardware. The state of the art of the new manufacturing methods, including additive manufacturing but also advanced bonding, joining and shaping techniques has been reviewed. Then three types of case studies have been developed successively. The first type was a re- manufacture of an existing piece of hardware using advanced techniques to evaluate if there is some potential improvement to be achieved (cost, production time, complexity reduction). The second level was to design and manufacture a part based on the application requirements. The last level was to design and manufacture a part taking into account the subsystem to which it belongs. All case studies have been tested in terms of achieved performances and resistance to the mechanical and thermal environment. [less ▲]

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See detailThe Extreme UV Imager of Solar Orbiter – From detailed design to Flight Model
Halain, Jean-Philippe ULg; Rochus, Pierre ULg; Renotte, Etienne ULg et al

in Proceedings of SPIE (2014), 9144

The Extreme Ultraviolet Imager (EUI) on-board the Solar Orbiter mission will provide full-sun and high-resolution image sequences of the solar atmosphere at selected spectral emission lines in the extreme ... [more ▼]

The Extreme Ultraviolet Imager (EUI) on-board the Solar Orbiter mission will provide full-sun and high-resolution image sequences of the solar atmosphere at selected spectral emission lines in the extreme and vacuum ultraviolet. After the breadboarding and prototyping activities that focused on key technologies, the EUI project has completed the design phase and has started the final manufacturing of the instrument and its validation. The EUI instrument has successfully passed its Critical Design Review (CDR). The process validated the detailed design of the Optical Bench unit and of its sub-units (entrance baffles, doors, mirrors, camera, and filter wheel mechanisms), and of the Electronic Box unit. In the same timeframe, the Structural and Thermal Model (STM) test campaign of the two units have been achieved, and allowed to correlate the associated mathematical models. The lessons learned from STM and the detailed design served as input to release the manufacturing of the Qualification Model (QM) and of the Flight Model (FM). The QM will serve to qualify the instrument units and sub-units, in advance of the FM acceptance tests and final on-ground calibration. [less ▲]

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See detailImportance of structural damping in the dynamic analysis of compliant deployable structures
Dewalque, Florence ULg; Rochus, Pierre ULg; Bruls, Olivier ULg

in Proceedings of the 65th International Astronautical Congress (IAC) (2014)

Compliant mechanisms such as tape springs are often used on satellites to deploy appendices, e.g. solar panels, antennas, telescopes and solar sails. Their main advantage comes from the fact that their ... [more ▼]

Compliant mechanisms such as tape springs are often used on satellites to deploy appendices, e.g. solar panels, antennas, telescopes and solar sails. Their main advantage comes from the fact that their motion results from the elastic deformation of structural components, unlike usual hinges or prismatic joints, the motion of which is dictated by contact surfaces. No actuators or external energy sources are required and the deployment is purely passive, which appears as a decisive feature for the design of low-cost missions with small satellites or cubesats. The mechanical behaviour of a tape spring is intrinsically complex and nonlinear involving buckling, hysteresis and self-locking phenomena. High-fidelity mechanical models are then needed to get a detailed understanding of the deployment process, improve the design and predict the actual behaviour in the space 0-g environment. In the majority of the previous works, dynamic simulations were performed without any physical representation of the structural damping. These simulations could be successfully achieved because of the presence of numerical damping in the transient solver. However, in this case, the dynamic response turns out to be quite sensitive to the amount of numerical dissipation, so that the predictive capabilities of the model are questionable. In this work based on numerical case studies, we show that the dynamic simulation of a tape spring can be made less sensitive to numerical parameters when the structural dissipation is taken into account. [less ▲]

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See detailAdvanced Thermal Control of Launcher Equipment Bay using Phase Change Material
Collette, JP; Rochus, Pierre ULg; Peyrou-Lauga, R et al

Conference (2013, September)

In the frame of ESA’s Future Launchers Preparatory Programme (FLPP), attention has been paid to the use of Phase Change Materials (PCM) for thermal control of Launchers. Among various possible ... [more ▼]

In the frame of ESA’s Future Launchers Preparatory Programme (FLPP), attention has been paid to the use of Phase Change Materials (PCM) for thermal control of Launchers. Among various possible applications, the avionics equipment bay of Ariane 5LV has been chosen to assess the performance of a Phase Change Material Heat Storage Device. Generally, the thermal control of the electronic units is passive and simply defined by their thermal inertia. In some specific case, an extra thermal inertia is added by using a spreader (thick Al plate) and the coupling with the platform is optimized. The price to pay is an extra mass for the launcher. A new concept of Phase Change Material device, using organic PCM, has recently been developed to improve the thermal control of spacecraft. This concept has been extended to the specific environment of a Launcher and to inorganic salt hydrates. The main results of this study are presented in this paper. [less ▲]

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See detailValidation of the Structural-Thermal-Model of the Small Earth Observation Satellite Flying Laptop
Steinmetz, Fabian; Lengowski, Michael; Winter, Daniel et al

Poster (2013, April 10)

Thorough thermal design and testing is compulsory for every satellite mission. A well-known thermal behavior of the entire satellite system is therefore indispensable and needs to be verified during the ... [more ▼]

Thorough thermal design and testing is compulsory for every satellite mission. A well-known thermal behavior of the entire satellite system is therefore indispensable and needs to be verified during the spacecraft development. A Structural-Thermal-Model (STM) was constructed for the Flying Laptop, a satellite currently being developed at the Institute of Space Systems (IRS) of the University of Stuttgart, which enables the validation of mechanical and thermal simulations for the satellite’s Flight-Model. The STM was vibration and thermal-vacuum tested at the Centre Spatial Liège (CSL). This paper will de-scribe the design and construction of the STM as well as the facilities and test equipment used for the tests. Conclusions will be drawn from the actual test results. [less ▲]

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See detailValidation of the Structural-Thermal Model of the Small Earth Observation Satellite Flying Laptop
Steinmetz, Fabian; Lengowski, Michael; Winter, Daniel et al

in Selected Proceedings of the 9th IAA International Symposium on Small Satellites for Earth Observation (2013, April 10)

Thorough thermal design and testing is compulsory for every satellite mission. A well-known thermal behavior of the entire satellite system is therefore indispensable and needs to be verified during the ... [more ▼]

Thorough thermal design and testing is compulsory for every satellite mission. A well-known thermal behavior of the entire satellite system is therefore indispensable and needs to be verified during the spacecraft development. A Structural-Thermal-Model (STM) was constructed for the Flying Laptop, a satellite currently being developed at the Institute of Space Systems (IRS) of the University of Stuttgart, which enables the validation of mechanical and thermal simulations for the satellite’s Flight-Model. The STM was vibration and thermal-vacuum tested at the Centre Spatial Liège (CSL). This paper will de-scribe the design and construction of the STM as well as the facilities and test equipment used for the tests. Conclusions will be drawn from the actual test results. [less ▲]

Detailed reference viewed: 90 (23 ULg)