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See detailMAGNETOHYDRODYNAMIC ENHANCED ENTRY SYSTEM FOR SPACE TRANSPORTATION (MEESST) AS A KEY BUILDING BLOCK FOR LOW-COST INTERPLANETARY MISSIONS
La Rosa Betancourt, Manuel; Collier-Wright, Marcus; Boegel, Elias et al

in Journal of the British Interplanetary Society (2022), 74(12), 448-453

Aside from the launch environment, atmospheric re-entry imposes one of the most demanding environments which a spacecraft can experience. The combination of high spacecraft velocity and the presence of ... [more ▼]

Aside from the launch environment, atmospheric re-entry imposes one of the most demanding environments which a spacecraft can experience. The combination of high spacecraft velocity and the presence of atmospheric particles leads to partially ionised gas forming around the vehicle, which significantly inhibits radio communications, and leads to the generation of high thermal loads on the spacecraft surface. Currently, the latter is solved using expensive, heavy, and often expendable thermal protection systems (TPS). The use of electromagnetic fields to exploit Magnetohydrodynamic (MHD) principles has long been considered as an attractive solution for this problem. By displacing the ionised gas away from the spacecraft, the thermal loads can be reduced, while also opening a magnetic window for radio waves, mitigating the blackout phenomenon. The application of this concept has to date not been possible due to the large magnetic fields required, which would necessitate the use of exceptionally massive and power-hungry copper coils. High Temperature Superconductors (HTS) have now reached industrial maturity. HTS coils can now offer the necessary low weight and compactness required for space applications. The MEESST consortium the has been awarded a grant from the EU Horizon 2020 programme for the development and demonstration of a novel HTS-based re-entry system based with its foundation on MHD principles. The project will first harmonize existing numerical codes, and then design, manufacture, and test a HTS magnet. The study shows that the use of MEESST technology can have a positive impact on the cost-effectiveness and available payload of interplanetary missions. [less ▲]

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See detailSpecial Issue on Very Low Earth Orbit Missions and Technologies
Roberts, Peter C. E.; Herdrich, Georg; Thoemel, Jan UL

in Roberts, Peter C. E.; Herdrich, Georg; Thoemel, Jan (Eds.) Special Issue on Very Low Earth Orbit Missions and Technologies (2022)

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See detailDeveloping a distributed and fractionated system of 10 grams satellites for planetary observation
Borgue, Olivia UL; Kanavouras, Konstantinos; Thoemel, Jan UL et al

in Proceedings of the International Astronautical Congress, IAC2 (2022)

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See detailThe “Daffodil” Mission: GNSS-Reflectometry with a 1.5U CubeSat
Wobler, Elliott; Vladyslav, Bohlachov; de Jesus Sousa, Tiago Alexandre UL et al

in Proceedings of the 73rd International Astronautical Congress (2022)

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See detailMission to Mars Using Space-Sourced Propellant
Thoemel, Jan UL; Karakatsanis, Panagiotis; Ludwikowski, Mariusz et al

in Proceedings of the International Astronautical Congress, IAC (2022)

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See detailThe Effect of an Applied Magnetic Field onto the Re-entry Radio Communication Blackout
Laur, Johannes UL; Giangaspero, Vincent; Sharma, Vitsalya et al

in Proceedings of the 2nd International Conference on Flight Vehicles, Aerothermodynamics and Re-entry Missions Engineering (2022)

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See detail5G Space Communications Lab: Reaching New Heights
Kodheli, Oltjon UL; Querol, Jorge UL; Astro, Abdelrahman et al

in Proceedings of the 18th International Conference on Distributed Computing in Sensor Systems (DCOSS) (2022)

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See detailA Magnetohydrodynamic enhanced entry system for space transportation: MEESST
Lani, Andrea; Sharma, Vatsalya; Giangaspero, Vincent F. et al

in Journal of Space Safety Engineering (2022)

This paper outlines the initial development of a novel magnetohydrodynamic (MHD) plasma control system which aims at mitigating shock-induced heating and the radio-frequency communication blackout ... [more ▼]

This paper outlines the initial development of a novel magnetohydrodynamic (MHD) plasma control system which aims at mitigating shock-induced heating and the radio-frequency communication blackout typically encountered during (re-)entry into planetary atmospheres. An international consortium comprising universities, SMEs, research institutions, and industry has been formed in order to develop this technology within the MEESST project. The latter is funded by the Future and Emerging Technologies (FET) program of the European Commission’s Horizon 2020 scheme (grant no. 899298). Atmospheric entry imposes one of the harshest environments which a spacecraft can experience. The combination of hypersonic velocities and the rapid compression of atmospheric particles by the spacecraft leads to high-enthalpy, partially ionised gases forming around the vehicle. This inhibits radio communications and induces high thermal loads on the spacecraft surface. For the former problem, spacecraft can sometimes rely on satellite constellations for communicating through the plasma wake and therefore preventing the blackout. On the other hand, expensive, heavy, and non-reusable thermal protection systems (TPS) are needed to dissipate the severe thermal loads. Such TPS can represent up to 30% of an entry vehicles weight, and especially for manned missions they can reduce the cost- efficiency by sacrificing payload mass. Such systems are also prone to failure, putting the lives of astronauts at risk. The use of electromagnetic fields to exploit MHD principles has long been considered as an attractive solution for tackling the problems described above. By pushing the boundary layer of the ionized gas layer away from the spacecraft, the thermal loads can be reduced, while also opening a magnetic window for radio communications and mitigating the blackout phenomenon. The application of this MHD-enabled system has previously not been demonstrated in realistic conditions due to the required large magnetic fields (on the order of Tesla or more), which for conventional technologies would demand exceptionally heavy and power-hungry electromagnets. High-temperature superconductors (HTS) have reached a level of industrial maturity sufficient for them to act as a key enabling technology for this application. Thanks to superior current densities, HTS coils can offer the necessary low weight and compactness required for space applications, with the ability to generate the strong magnetic fields needed for entry purposes. This paper provides an overview of the MEESST project, including its goals, methodology and some preliminary design considerations. [less ▲]

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See detailSolar-Aerodynamic Formation Flight for 5G Experiments
Thoemel, Jan UL; Querol, Jorge UL; Bokal, Zhanna UL et al

in Proceedings of the 12th European CubeSatSymposium (2021, November 15)

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See detailGlobal land dampness characterization using reflectometry by students (GOLDCREST): mission and CubeSat design
Asadi, Niloofar; Gholami-Boroujeni, Farzaneh; Gogoi, Bishwajit et al

in Proceedings of the 12th European CubeSat symposium (2021, November 15)

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See detail5G-SpaceLab
Querol, Jorge UL; Abdalla, Abdelrahman UL; Bokal, Zhanna UL et al

Poster (2021, April 19)

The new phase of space exploration involves a growing number of human and robotic missions with varying communication and service requirements. Continuous, maximum coverage of areas where activities are ... [more ▼]

The new phase of space exploration involves a growing number of human and robotic missions with varying communication and service requirements. Continuous, maximum coverage of areas where activities are concentrated and orbiting missions (single spacecraft or constellations) around the Earth, Moon or Mars will be particularly challenging. The standardization of the 5G Non-Terrestrial Networks (NTN) has already begun [1], and nothing prevents 5G from becoming a common communications standard supporting space resource missions [2]. The 5G Space Communications Lab (5G-SpaceLab) is an interdisciplinary experimental platform, funded by the Luxembourg Space Agency and is part of the Space Research Program of SnT. The lab allows users to design and emulate realistic space communications and control scenarios for the next-generation of space applications. The capabilities of the 5G-SpaceLab testbed combine the experience of different disciplines including space communications, space and satellite mission design, and space robotics. The most relevant include the demonstration of SDR 5G NTN terminals including NB-IoT, emulation of space communications channel scenarios (e.g. link budget, delay, Doppler…), small satellite platform and payload design and testing, satellite swarm flight formation, lunar rover and robotic arm control and AI-powered telerobotics. Earth-Moon communications is one of the scenarios demonstrated in the 5G-SpaceLab. Bidirectional communication for the teleoperation of lunar rovers for near real-time operations including data collection and sensors feedback will be tested. AI-based approaches for perception and control will be developed to overcome communication delays and to provide safer, trustworthy, and efficient remote control of the rovers. [1] 3GPP Release 17 Timeline. [Online]. Available: https://www.3gpp.org/release-17 [2] Nokia, Nokia selected by NASA to build first ever cellular network on the Moon. [Online]. Available: https://www.nokia.com/about-us/news/releases/2020/10/19/nokia-selected-by-nasa-to-build-first-ever-cellular-network-on-the-moon/ [less ▲]

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See detailRadio communication blackout analysis of ExoMars re-entry mission using raytracing method
Vincent F. Giangaspero, ; Lani, Andrea; Poedts, Stefaan et al

in Radio communication blackout analysis of ExoMars re-entry mission using raytracing method (2021, January)

This work presents a numerical methodology to properly characterize and predict the ommunications blackout phase of the ExoMars Schiaparelli Martian atmospheric re-entry flight. The focus of this work ... [more ▼]

This work presents a numerical methodology to properly characterize and predict the ommunications blackout phase of the ExoMars Schiaparelli Martian atmospheric re-entry flight. The focus of this work lies on the use of an optical ray tracing technique to describe the electromagnetic waves behaviour within the ionized wake flow of the vehicle. Bi-dimensional hypersonic CFD simulations are performed over the ExoMars Schiaparelli module at different trajectory points with the COOLFluiD aerothermodynamics Finite Volume solver coupled with the thermochemistry library PLATO. Subsequently, a ray tracing algorithm is applied to examine the propagation of electromagnetic waves and their interaction with the re-entry wake flow of the ExoMars vehicle. In this work, results are presented at three different trajectory points, characterized by different ionization levels of the flow. The results show how this methodology is suited to analyze blackout re-entry phases providing useful information on electromagnetic waves behaviour in ionized plasma re-entry flows. [less ▲]

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See detailAutonomous Formation Flight using Solar Radiation Pressure
Thoemel, Jan UL; van Dam, Tonie UL

in CEAS Space Journal (2020)

Autonomous formation flight enables new satellite missions for novel applications. The cost and limits of propulsion systems can be overcome if environmental resources are being benefitted of. Currently ... [more ▼]

Autonomous formation flight enables new satellite missions for novel applications. The cost and limits of propulsion systems can be overcome if environmental resources are being benefitted of. Currently, atmospheric drag is used in low Earth orbit to this end. Solar radiation pressure, which is of similar order of magnitude as aerodynamic ram pressure, is, however, always neglected. We introduce this force and show that it can be exploited. We demonstrate through simulations that a formation geometry is established quicker if the solar radiation pressure is modeled. [less ▲]

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See detailBlackout analysis of Mars entry missions
Ramjatan, Sahadeo; Lani, Andrea; Boccelli, Stefan et al

in Journal of Fluid Mechanics (2020)

A new methodology to accurately and efficiently examine the radio frequency blackout phenomenon during the hypersonic reentry process is introduced and validated. The current state-of-the-art ... [more ▼]

A new methodology to accurately and efficiently examine the radio frequency blackout phenomenon during the hypersonic reentry process is introduced and validated. The current state-of-the-art thermochemical modelling of CO2 flows is reviewed and one-dimensional stagnation line studies are performed in order to determine a suitable chemical mechanism for the electron density modelling. Hypersonic computational fluid dynamics (CFD) simulations are performed with a simplified chemical model including only neutral species, in order to calculate the flow field surrounding the ExoMars Schiapparelli module in flight conditions. A novel decoupled CFD approach is then applied where the calculation of the electron density is performed separately using a computationally inexpensive Lagrangian approach. Subsequently, a ray tracing algorithm is applied in order to model the propagation of electromagnetic waves in the wake flow past the ExoMars vehicle accounting for collisions between electrons and gas particles. The numerical results of the proposed novel approach for blackout analysis consisting of CFD, Lagrangian and ray tracing algorithms are in good agreement with the flight data. [less ▲]

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See detailAnalysis of Autonomous Propellent-Less Formation Flight
Thoemel, Jan UL

in Proceedings of the 11th European CubeSat Symposium (2019)

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See detailOn the accuracy of the SGP4 to predict stellar occultation events using ENVISAT/GOMOS data and recommendations for the ALTIUS mission
Thoemel, Jan UL; Mateshvili, Nina; Demoulin, Philippe et al

in CEAS Space Journal (2019), 11(2), 147--159

In preparation for the operations of the ALTIUS mission, research is carried out to assess the accuracy of the SGP4 orbital propagator in predicting stellar occultation events. The quantification of the ... [more ▼]

In preparation for the operations of the ALTIUS mission, research is carried out to assess the accuracy of the SGP4 orbital propagator in predicting stellar occultation events. The quantification of the accuracy and its consequent improvement will enable reliable measurement planning and, therefore, maximize the number of measurements. To this end, predictions are made for the timing of occultations for the GOMOS instrument on-board the ENVISAT, which are then compared to actual occultation occurrences. It is found that the error is substantial but follows a trend that can be interpolated. This enables devising a method for highly accurate predictions given a sufficient number of data points. Statistically significant results for the accuracy of the propagator and a calibration method are presented. Recommendations for a measurement planning procedure of ALTIUS are formulated. [less ▲]

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See detailThe GomX4 satellites for multispectral earth observation and AIS and ADSB data acquisition
Thoemel, Jan UL

in Proceedings of the 4th Luxembourg Earth Observation (EO) and Integrated Applications Day (2018)

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See detailBlackout analysis of small cone-shaped reentry vehicles
Ramjatan, Sahadeo; Magin, Thierry; Scholz, Thorsten et al

in Journal of Thermophysics and Heat Transfer (2017), 31(2), 269--282

The high temperatures associated with the hypersonic reentry process lead to an increase in the collisions between molecules, which may result in the disruption of the electronic structure, producing free ... [more ▼]

The high temperatures associated with the hypersonic reentry process lead to an increase in the collisions between molecules, which may result in the disruption of the electronic structure, producing free electrons and ions. This production of free electrons and ions creates a plasma or ionized flowfield around the vehicle that is known to degrade the quality of radio-wave signal propagation, leading to a loss of communication or "blackout." This study involves performing hypersonic computational fluid dynamics simulations in the commercial software CFD++ with a bluntnosed cone geometry at different flight conditions to predict how and when ground communication can be achieved to aid in the design of an alert transmitter, which is an extension of aircraft collision-avoidance system technology. Computational results show that a small blunt-nosed cone geometry has decreased ionization regions as the cone angle decreases due to a shifting of the reaction zone further downstream. As a result, higher freestream velocities have less of an impact in determining the location for an antenna, and communicating along the stagnation line is seen to be independent of cone angle. [less ▲]

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See detailEffect of the solar activity variation on the Global Ionosphere Thermosphere Model (GITM)
Masutti, Davide; March, Günther; Ridley, Aaron J. et al

in Annales Geophysicae (2016), 34(9), 725--736

The accuracy of global atmospheric models used to predict the middle/lower thermosphere characteristics is still an open topic. Uncertainties in the prediction of the gas properties in the thermosphere ... [more ▼]

The accuracy of global atmospheric models used to predict the middle/lower thermosphere characteristics is still an open topic. Uncertainties in the prediction of the gas properties in the thermosphere lead to inaccurate computations of the drag force on space objects (i.e. satellites or debris). Currently the lifetime of space objects and therefore the population of debris in low Earth orbit (LEO) cannot be quantified with a satisfactory degree of accuracy. In this paper, the Global Ionosphere Thermosphere Model (GITM) developed at the University of Michigan has been validated in order to provide detailed simulations of the thermosphere. First, a sensitivity analysis has been performed to investigate the effect of the boundary conditions on the final simulations results. Then, results of simulations have been compared with flight measurements from the CHallenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellites and with existing semi-empirical atmospheric models (IRI and MSIS). The comparison shows a linear dependency of the neutral density values with respect to the solar activity. In particular, GITM shows an over-predicting or under-predicting behaviour under high or low solar activity respectively. The reasons for such behaviour can be attributed to a wrong implementation of the chemical processes or the gas transport properties in the model. [less ▲]

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