Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/3483
2024-03-19T07:00:26ZDISCOVERER: Final results and outcomes
http://hdl.handle.net/2117/375680
DISCOVERER: Final results and outcomes
Roberts, Peter C.E; Crisp, Nicholas H.; Edmonson, Steve; Arcos, Antonio; Herdrich, Georg; Skalden, Jonathan; Rodríguez Donaire, Silvia; García-Almiñana, Daniel; Macario Rojas, Alejandro; Smith, Katharine L.; Sureda Anfres, Miquel
The DISCOVERER project commenced in 2017 with the aim to advance the development of key technologies to enable the commercially viable, sustained operation of satellites in very low Earth orbits (VLEO). Funded by the European Commission through Horizon 2020, the project ends this month. This paper presents an overview of the key achievements and current status of the project. The project set out to advance the development of, and demonstrate, several technologies with the long-term aim
of enabling the commercial use of VLEO. These technologies include:
1. aerodynamic materials which encourage specular scattering of the incoming flow to minimise drag and increase the performance of aerodynamic surfaces in the highly rarefied flows experienced in VLEO
2. aerodynamic attitude control methods to compensate for the dynamic flow environment, especially lower in the VLEO altitude range
3. atmosphere breathing electric propulsion (ABEP), combining an optimised atmospheric intake with advanced RF Helicon-based plasma thruster, for drag compensation
DISCOVERER’s test satellite, the Satellite for Orbital Aerodynamics Research or SOAR, was deployed from the International Space Station in June 2021 and re-entered the atmosphere in March 2022. The primary aim was to measure the induced drag and lift on different aerodynamic materials candidates in VLEO by exposing panels, coated in various novel and control materials, to the flow at different orientations whilst observing the induced attitude and orbit perturbations produced. Early analysis of the results from the mission shows promising results for the novel materials developed as part of the project. Parallel studies on the long-term survivability of these materials to the space environment have been on-going through exposure tests on the exterior of the International Space Station through the MISSE programme.
The project has also been developing a ground-based facility, the Rarefied Orbital Aerodynamics Research facility, to characterise the gas surface interaction properties of materials to atomic oxygen at orbital velocities. Characterisation of the facility itself is on-going. In support of ABEP technology, the experimental development and characterisation of an RF Helicon-based plasma thruster has been on-going, along with detailed computational modelling of aerodynamic intakes. Whilst the thruster has already been operated, current work focusses on the characterisation of its performance. Finally, work to place these technological developments into context has also been progressed. On overview of the overall achievements in this area is provided, including business modelling of the VLEO market ecosystem, which identifies the enormous market potential for VLEO missions.
2022-11-04T12:46:03ZRoberts, Peter C.ECrisp, Nicholas H.Edmonson, SteveArcos, AntonioHerdrich, GeorgSkalden, JonathanRodríguez Donaire, SilviaGarcía-Almiñana, DanielMacario Rojas, AlejandroSmith, Katharine L.Sureda Anfres, MiquelThe DISCOVERER project commenced in 2017 with the aim to advance the development of key technologies to enable the commercially viable, sustained operation of satellites in very low Earth orbits (VLEO). Funded by the European Commission through Horizon 2020, the project ends this month. This paper presents an overview of the key achievements and current status of the project. The project set out to advance the development of, and demonstrate, several technologies with the long-term aim
of enabling the commercial use of VLEO. These technologies include:
1. aerodynamic materials which encourage specular scattering of the incoming flow to minimise drag and increase the performance of aerodynamic surfaces in the highly rarefied flows experienced in VLEO
2. aerodynamic attitude control methods to compensate for the dynamic flow environment, especially lower in the VLEO altitude range
3. atmosphere breathing electric propulsion (ABEP), combining an optimised atmospheric intake with advanced RF Helicon-based plasma thruster, for drag compensation
DISCOVERER’s test satellite, the Satellite for Orbital Aerodynamics Research or SOAR, was deployed from the International Space Station in June 2021 and re-entered the atmosphere in March 2022. The primary aim was to measure the induced drag and lift on different aerodynamic materials candidates in VLEO by exposing panels, coated in various novel and control materials, to the flow at different orientations whilst observing the induced attitude and orbit perturbations produced. Early analysis of the results from the mission shows promising results for the novel materials developed as part of the project. Parallel studies on the long-term survivability of these materials to the space environment have been on-going through exposure tests on the exterior of the International Space Station through the MISSE programme.
The project has also been developing a ground-based facility, the Rarefied Orbital Aerodynamics Research facility, to characterise the gas surface interaction properties of materials to atomic oxygen at orbital velocities. Characterisation of the facility itself is on-going. In support of ABEP technology, the experimental development and characterisation of an RF Helicon-based plasma thruster has been on-going, along with detailed computational modelling of aerodynamic intakes. Whilst the thruster has already been operated, current work focusses on the characterisation of its performance. Finally, work to place these technological developments into context has also been progressed. On overview of the overall achievements in this area is provided, including business modelling of the VLEO market ecosystem, which identifies the enormous market potential for VLEO missions.Platform and system design study of a VLEO satellite platform using the IRS RF Helicon-based Plasma Thruster
http://hdl.handle.net/2117/374448
Platform and system design study of a VLEO satellite platform using the IRS RF Helicon-based Plasma Thruster
Herdrich, Georg; Papavramidis, Konstantinos; Maier, Philipp; García-Almiñana, Daniel; Rodríguez Donaire, Silvia; Sureda Anfres, Miquel
To achieve a feasible lifetime of several years, most satellites are deployed in orbits higher than 400 km. Drag of residual atmosphere causes a slow orbit decay, resulting in the deorbit of the spacecraft. However, e.g. optical instruments or communication devices would significantly benefit from lower altitudes in the range of 150-250 km. A solution to achieve this could be the application of atmosphere-breathing electric propulsion (ABEP), where the residual atmosphere is used to generate continuous thrust that compensates the drag. Within the EU-funded DISCOVERER project, the Institute of Space Systems (IRS) developed an electrode-less RF Helicon-based Plasma Thruster (IPT) suitable for such applications. Ignition and preliminary discharge characterizations of the IPT have been carried out at IRS facilities, using argon, nitrogen and oxygen. To further characterize the plasma plume, a torsional pendulum has been designed to determine the momentum flux in the plasma jet, as well as a three-axis magnetic B-dot probe to carry out time-varying magnetic field measurements. Various intake designs were investigated, opening the possibility to conduct studies on potential satellite platforms. A design study for an Earth Observation and Telecommunication satellite operating at 150-250 km with an extended mission lifetime is currently being carried out. The first system assessment focused on the comparison of different spacecraft configurations (“slender body” and “flat body”) and intake designs (specular or diffuse) with regard to overall drag and ABEP performance requirements. In this contribution, the proposed thruster characterization methods and the current status of the system assessment are presented. Upcoming experimental studies of the ABEP system and additional activities planned on system assessment are outlined.
2022-10-14T12:11:59ZHerdrich, GeorgPapavramidis, KonstantinosMaier, PhilippGarcía-Almiñana, DanielRodríguez Donaire, SilviaSureda Anfres, MiquelTo achieve a feasible lifetime of several years, most satellites are deployed in orbits higher than 400 km. Drag of residual atmosphere causes a slow orbit decay, resulting in the deorbit of the spacecraft. However, e.g. optical instruments or communication devices would significantly benefit from lower altitudes in the range of 150-250 km. A solution to achieve this could be the application of atmosphere-breathing electric propulsion (ABEP), where the residual atmosphere is used to generate continuous thrust that compensates the drag. Within the EU-funded DISCOVERER project, the Institute of Space Systems (IRS) developed an electrode-less RF Helicon-based Plasma Thruster (IPT) suitable for such applications. Ignition and preliminary discharge characterizations of the IPT have been carried out at IRS facilities, using argon, nitrogen and oxygen. To further characterize the plasma plume, a torsional pendulum has been designed to determine the momentum flux in the plasma jet, as well as a three-axis magnetic B-dot probe to carry out time-varying magnetic field measurements. Various intake designs were investigated, opening the possibility to conduct studies on potential satellite platforms. A design study for an Earth Observation and Telecommunication satellite operating at 150-250 km with an extended mission lifetime is currently being carried out. The first system assessment focused on the comparison of different spacecraft configurations (“slender body” and “flat body”) and intake designs (specular or diffuse) with regard to overall drag and ABEP performance requirements. In this contribution, the proposed thruster characterization methods and the current status of the system assessment are presented. Upcoming experimental studies of the ABEP system and additional activities planned on system assessment are outlined.Very low Earth orbit constellations for Earth observation
http://hdl.handle.net/2117/374440
Very low Earth orbit constellations for Earth observation
Crisp, Nicholas H.; McGrath, Ciara N.; Roberts, Peter C.E; García-Almiñana, Daniel; Rodríguez Donaire, Silvia; Sureda Anfres, Miquel
Very Low Earth Orbits (VLEOs), those below 450 km, present a number of benefits and challenges for the development and operation of Earth observation spacecraft at both the system and mission level. This paper examines the design of constellations of satellites for operation in VLEO for Earth observation considering both system and mission level trade-offs. The resulting analysis identifies general design trends and proposes suitable mission architectures for Earth observation from VLEO. The principal benefit for satellites operating in VLEO is that the reduction in the distance to the Earth’s surface allows better imaging resolution to be achieved using smaller and less powerful payloads. This has corresponding benefits for the system mass and cost. However, the sustained and controlled operation of spacecraft in VLEO is challenging due to the increased atmospheric density at these altitudes, which increases propulsive and attitude control requirements. Technologies to facilitate the commercially viable operation of spacecraft in VLEO are currently being developed, for example materials to facilitate drag-reduction and aerodynamic control and atmosphere-breathing electric propulsion systems (ABEP), each of which influence the design of other sub-systems, requiring, for example, varying levels of power or new geometric considerations. At the mission level, the reduction in altitude has a generally negative influence on the coverage and revisit characteristics of a given satellite. However, deployment of these satellites in constellations can provide improvements in the overall system metrics. Systems operating in VLEO may also benefit from improved launch vehicle capability and assured end-of-life deorbit. It is clear, therefore, that important and non-intuitive trade-offs between the satellite platform design, constellation configuration, and total cost arise in the design of these systems. This paper uses combined platform-level system modelling and mission analysis to explore the design of constellations of satellites in VLEO for Earth observation and demonstrates the necessity of a holistic approach to mission and system design when considering operations in VLEO.
2022-10-14T11:03:31ZCrisp, Nicholas H.McGrath, Ciara N.Roberts, Peter C.EGarcía-Almiñana, DanielRodríguez Donaire, SilviaSureda Anfres, MiquelVery Low Earth Orbits (VLEOs), those below 450 km, present a number of benefits and challenges for the development and operation of Earth observation spacecraft at both the system and mission level. This paper examines the design of constellations of satellites for operation in VLEO for Earth observation considering both system and mission level trade-offs. The resulting analysis identifies general design trends and proposes suitable mission architectures for Earth observation from VLEO. The principal benefit for satellites operating in VLEO is that the reduction in the distance to the Earth’s surface allows better imaging resolution to be achieved using smaller and less powerful payloads. This has corresponding benefits for the system mass and cost. However, the sustained and controlled operation of spacecraft in VLEO is challenging due to the increased atmospheric density at these altitudes, which increases propulsive and attitude control requirements. Technologies to facilitate the commercially viable operation of spacecraft in VLEO are currently being developed, for example materials to facilitate drag-reduction and aerodynamic control and atmosphere-breathing electric propulsion systems (ABEP), each of which influence the design of other sub-systems, requiring, for example, varying levels of power or new geometric considerations. At the mission level, the reduction in altitude has a generally negative influence on the coverage and revisit characteristics of a given satellite. However, deployment of these satellites in constellations can provide improvements in the overall system metrics. Systems operating in VLEO may also benefit from improved launch vehicle capability and assured end-of-life deorbit. It is clear, therefore, that important and non-intuitive trade-offs between the satellite platform design, constellation configuration, and total cost arise in the design of these systems. This paper uses combined platform-level system modelling and mission analysis to explore the design of constellations of satellites in VLEO for Earth observation and demonstrates the necessity of a holistic approach to mission and system design when considering operations in VLEO.Experimental Results from the Satellite for Orbital Aerodynamics Research (SOAR) Mission
http://hdl.handle.net/2117/374439
Experimental Results from the Satellite for Orbital Aerodynamics Research (SOAR) Mission
Crisp, Nicholas H.; Macario Rojas, Alejandro; Roberts, Peter C.E; García-Almiñana, Daniel; Sureda Anfres, Miquel; Rodríguez Donaire, Silvia
The Satellite for Orbital Aerodynamics Research (SOAR) is a 3U CubeSat that has been designed to investigate the aerodynamic performance of different materials and perform demonstrations of aerodynamic attitude control manoeuvres in very low Earth orbit (VLEO). SOAR was deployed from the ISS on 14th June 2021 into a naturally decaying orbit and deorbited on 14th March 2022. This paper provides an overview of the operations performed during the mission and presents preliminary experimental results obtained from this spacecraft. SOAR was designed and launched within the frame of DISCOVERER, a Horizon 2020 project that aimed to support the development of a new class of commercially viable spacecraft operating in VLEO, i.e., orbits below 450 km in altitude. Operating in these lower altitude orbits has several benefits to the design of spacecraft, particularly for Earth observation and communications applications. However, development of spacecraft that can operate sustainably at these altitudes requires advancement in foundational technologies, for example atmosphere-breathing electric propulsion (ABEP) and novel aerodynamic materials. The primary aim of SOAR was to characterise the aerodynamic performance of different materials at very low altitudes and accomplished this task using a set of steerable fins that exposed different materials to the oncoming flow and an ion and neutral mass spectrometer (INMS) to provide in-situ measurements of atmospheric properties. SOAR was also designed to perform novel aerodynamic attitude control manoeuvres and measurements of thermospheric winds. Two of the materials carried to orbit were selected for their atomic oxygen erosion resistance and potential improvement in aerodynamic performance. The identification of such materials would allow for a reduction in the drag experienced in VLEO, the design of atmospheric intakes with greater efficiency used for ABEP, and implementation of enhanced aerodynamic attitude and orbit control. Ongoing ground-based experimentation seeks to further characterise the properties of such materials and to deepen our understanding of the physical interaction mechanisms that occur in the rarefied flow environment of VLEO.
2022-10-14T10:43:22ZCrisp, Nicholas H.Macario Rojas, AlejandroRoberts, Peter C.EGarcía-Almiñana, DanielSureda Anfres, MiquelRodríguez Donaire, SilviaThe Satellite for Orbital Aerodynamics Research (SOAR) is a 3U CubeSat that has been designed to investigate the aerodynamic performance of different materials and perform demonstrations of aerodynamic attitude control manoeuvres in very low Earth orbit (VLEO). SOAR was deployed from the ISS on 14th June 2021 into a naturally decaying orbit and deorbited on 14th March 2022. This paper provides an overview of the operations performed during the mission and presents preliminary experimental results obtained from this spacecraft. SOAR was designed and launched within the frame of DISCOVERER, a Horizon 2020 project that aimed to support the development of a new class of commercially viable spacecraft operating in VLEO, i.e., orbits below 450 km in altitude. Operating in these lower altitude orbits has several benefits to the design of spacecraft, particularly for Earth observation and communications applications. However, development of spacecraft that can operate sustainably at these altitudes requires advancement in foundational technologies, for example atmosphere-breathing electric propulsion (ABEP) and novel aerodynamic materials. The primary aim of SOAR was to characterise the aerodynamic performance of different materials at very low altitudes and accomplished this task using a set of steerable fins that exposed different materials to the oncoming flow and an ion and neutral mass spectrometer (INMS) to provide in-situ measurements of atmospheric properties. SOAR was also designed to perform novel aerodynamic attitude control manoeuvres and measurements of thermospheric winds. Two of the materials carried to orbit were selected for their atomic oxygen erosion resistance and potential improvement in aerodynamic performance. The identification of such materials would allow for a reduction in the drag experienced in VLEO, the design of atmospheric intakes with greater efficiency used for ABEP, and implementation of enhanced aerodynamic attitude and orbit control. Ongoing ground-based experimentation seeks to further characterise the properties of such materials and to deepen our understanding of the physical interaction mechanisms that occur in the rarefied flow environment of VLEO.Launch, Operations, and First Experimental Results of the Satellite for Orbital Aerodynamics Research (SOAR)
http://hdl.handle.net/2117/359050
Launch, Operations, and First Experimental Results of the Satellite for Orbital Aerodynamics Research (SOAR)
Crisp, Nicholas H.; Macario Rojas, Alejandro; Roberts, Peter C.E; Edmonson, Steve; Haigh, Sarah J.; Holmes, Brandon E.A.; Livadiotti, Sabrina; Oiko, Vitor; Smith, Katharine L.; Sinpetru, Luciana A.; García-Almiñana, Daniel; Rodríguez Donaire, Silvia; Sureda Anfres, Miquel
The Satellite for Orbital Aerodynamics Research (SOAR) is a 3U CubeSat that has been designed to investigate the aerodynamic performance of different materials at low orbital altitudes. The spacecraft has been developed within the scope of DISCOVERER, a Horizon 2020 project that aims to develop foundational technologies to enable sustainable operations of Earth observation spacecraft in very low Earth orbits (VLEO) i.e., those below 450 km. SOAR features two payloads: i) a set of steerable fins that can expose different materials to the oncoming atmospheric flow developed by The University of Manchester, and ii) a forward-facing ion and neutral mass spectrometer (INMS) that provides in-situ measurements of the atmospheric density, flow composition, and velocity from the Mullard Space Science Laboratory (MSSL) of University College London. These payloads enable characterisation of the aerodynamic performance of different materials at very low altitudes with the aim to advance understanding of the underlying gas-surface interactions in rarefied flow environments. The satellite will also be used to test novel aerodynamic attitude control methods and perform atmospheric characterisation in the VLEO altitude range. SOAR will perform the first in-orbit test of two novel materials that are expected to have atomic oxygen erosion resistance and drag-reducing properties, providing valuable in-orbit validation data for ongoing ground-based experimentation. Such materials hold the promise for extending operations at lower altitudes with benefits particularly for Earth observation and communications satellites that can correspondingly be reduced in size and cost. The platform for SOAR is largely based on GOMX-3 heritage and the spacecraft was assembled, integrated, and tested by GomSpace A/S. The satellite was launched on the SpX-22 commercial resupply service mission to the International Space Station in on 3rd June 2021 was subsequently deployed into orbit on the 14th June 2021. This paper presents the final preparations of SOAR prior to launch and provides an overview of the planned operations of the spacecraft following deployment into orbit.
2021-12-22T14:35:00ZCrisp, Nicholas H.Macario Rojas, AlejandroRoberts, Peter C.EEdmonson, SteveHaigh, Sarah J.Holmes, Brandon E.A.Livadiotti, SabrinaOiko, VitorSmith, Katharine L.Sinpetru, Luciana A.García-Almiñana, DanielRodríguez Donaire, SilviaSureda Anfres, MiquelThe Satellite for Orbital Aerodynamics Research (SOAR) is a 3U CubeSat that has been designed to investigate the aerodynamic performance of different materials at low orbital altitudes. The spacecraft has been developed within the scope of DISCOVERER, a Horizon 2020 project that aims to develop foundational technologies to enable sustainable operations of Earth observation spacecraft in very low Earth orbits (VLEO) i.e., those below 450 km. SOAR features two payloads: i) a set of steerable fins that can expose different materials to the oncoming atmospheric flow developed by The University of Manchester, and ii) a forward-facing ion and neutral mass spectrometer (INMS) that provides in-situ measurements of the atmospheric density, flow composition, and velocity from the Mullard Space Science Laboratory (MSSL) of University College London. These payloads enable characterisation of the aerodynamic performance of different materials at very low altitudes with the aim to advance understanding of the underlying gas-surface interactions in rarefied flow environments. The satellite will also be used to test novel aerodynamic attitude control methods and perform atmospheric characterisation in the VLEO altitude range. SOAR will perform the first in-orbit test of two novel materials that are expected to have atomic oxygen erosion resistance and drag-reducing properties, providing valuable in-orbit validation data for ongoing ground-based experimentation. Such materials hold the promise for extending operations at lower altitudes with benefits particularly for Earth observation and communications satellites that can correspondingly be reduced in size and cost. The platform for SOAR is largely based on GOMX-3 heritage and the spacecraft was assembled, integrated, and tested by GomSpace A/S. The satellite was launched on the SpX-22 commercial resupply service mission to the International Space Station in on 3rd June 2021 was subsequently deployed into orbit on the 14th June 2021. This paper presents the final preparations of SOAR prior to launch and provides an overview of the planned operations of the spacecraft following deployment into orbit.Early Results from the DISCOVERER Project
http://hdl.handle.net/2117/358998
Early Results from the DISCOVERER Project
Roberts, Peter C.E; Crisp, Nicholas H.; Oiko, Vitor; Edmonson, Steve; Romano, Francesco; Rodríguez Donaire, Silvia; García-Almiñana, Daniel; Haigh, Sarah J.; Holmes, Brandon E.A.; Livadiotti, Sabrina; Sureda Anfres, Miquel
The use of very low Earth orbits (VLEO), for communications and remote sensing satellites, offers a number of significant payload and platform benefits. Imaging from these altitudes allows higher resolution or smaller optical payloads, whilst radar also benefits from improved link budgets leading to smaller antennas and lower transmission power. Communications payloads also have improved link budgets, reduced latency, and improved frequency reuse factors. Platform benefits include a more benign radiation environment, lower cost per kilogram to launch satellites, and atmospheric drag makes the environment inherently sustainable, simultaneously removing debris objects and ensuring satellites are quickly removed from orbit at the end of their operational lives. However, the impact of drag on satellite and mission operations must also be addressed. The DISCOVERER project, which commenced in 2017, is addressing the following key questions about technologies that would enable the commercially viable and sustained operation of satellites in VLEO: 1. Are there materials or processes which reduce the induced drag on spacecraft surfaces? 2. Are there propulsion methods which use the residual atmospheric gas as a propellant, providing drag compensation whilst removing the lifetime limits caused by carrying a limited amount of propellant? 3. How can we improve our understanding of, and make best use of, the orbital aerodynamics of a space platform and its ability to perform attitude control manoeuvres? 4. And what are the new opportunities that these technologies may bring to the market? This paper provides highlights from the developments made during the DISCOVERER project to date, demonstrating the potential for a new, commercially attractive, class of aerodynamic satellites operating in VLEO.
2021-12-21T17:31:47ZRoberts, Peter C.ECrisp, Nicholas H.Oiko, VitorEdmonson, SteveRomano, FrancescoRodríguez Donaire, SilviaGarcía-Almiñana, DanielHaigh, Sarah J.Holmes, Brandon E.A.Livadiotti, SabrinaSureda Anfres, MiquelThe use of very low Earth orbits (VLEO), for communications and remote sensing satellites, offers a number of significant payload and platform benefits. Imaging from these altitudes allows higher resolution or smaller optical payloads, whilst radar also benefits from improved link budgets leading to smaller antennas and lower transmission power. Communications payloads also have improved link budgets, reduced latency, and improved frequency reuse factors. Platform benefits include a more benign radiation environment, lower cost per kilogram to launch satellites, and atmospheric drag makes the environment inherently sustainable, simultaneously removing debris objects and ensuring satellites are quickly removed from orbit at the end of their operational lives. However, the impact of drag on satellite and mission operations must also be addressed. The DISCOVERER project, which commenced in 2017, is addressing the following key questions about technologies that would enable the commercially viable and sustained operation of satellites in VLEO: 1. Are there materials or processes which reduce the induced drag on spacecraft surfaces? 2. Are there propulsion methods which use the residual atmospheric gas as a propellant, providing drag compensation whilst removing the lifetime limits caused by carrying a limited amount of propellant? 3. How can we improve our understanding of, and make best use of, the orbital aerodynamics of a space platform and its ability to perform attitude control manoeuvres? 4. And what are the new opportunities that these technologies may bring to the market? This paper provides highlights from the developments made during the DISCOVERER project to date, demonstrating the potential for a new, commercially attractive, class of aerodynamic satellites operating in VLEO.Aerodynamic Technologies for Earth Observation Missions in Very Low earth Orbit
http://hdl.handle.net/2117/330584
Aerodynamic Technologies for Earth Observation Missions in Very Low earth Orbit
Becedas, Jonathan; González, Gerardo; Domínguez, Rosa María; García-Almiñana, Daniel; Rodríguez Donaire, Silvia; Sureda Anfres, Miquel
Flying at VLEO has several advantages such as the increase of the resolution of images recorded by optical instruments, the increase of geospatial position accuracy, the improvement of the signal to noise ratio and the reduction of energy consumption by active payloads. However, the drag produced by the interaction of the atmospheric gas particles with the surfaces of the spacecraft requires an extended knowledge of orbital aerodynamics. The aim of this work is to carry out a study from the principles of orbital aerodynamics to the definition of requirements for a set of satellite platforms covering Earth Observation applications taking advantage of operating in Very Low Earth Orbit (VLEO) and making use of aerodynamic technologies. Four platform concepts were defined: optical coverage platforms, optical Very High Resolution (VHR) for high performance platforms, low cost optical VHR platforms and Synthetic Aperture Radar (SAR) platforms. In addition, the main orbit and attitude control operations to be done with these concepts were analyzed. A relation between the different mission concepts and the performances to be obtained with enhanced aerodynamics was established to identify which of the four platform concepts could perform as a commercial platform to guarantee the use for different applications.
2020-10-21T13:18:09ZBecedas, JonathanGonzález, GerardoDomínguez, Rosa MaríaGarcía-Almiñana, DanielRodríguez Donaire, SilviaSureda Anfres, MiquelFlying at VLEO has several advantages such as the increase of the resolution of images recorded by optical instruments, the increase of geospatial position accuracy, the improvement of the signal to noise ratio and the reduction of energy consumption by active payloads. However, the drag produced by the interaction of the atmospheric gas particles with the surfaces of the spacecraft requires an extended knowledge of orbital aerodynamics. The aim of this work is to carry out a study from the principles of orbital aerodynamics to the definition of requirements for a set of satellite platforms covering Earth Observation applications taking advantage of operating in Very Low Earth Orbit (VLEO) and making use of aerodynamic technologies. Four platform concepts were defined: optical coverage platforms, optical Very High Resolution (VHR) for high performance platforms, low cost optical VHR platforms and Synthetic Aperture Radar (SAR) platforms. In addition, the main orbit and attitude control operations to be done with these concepts were analyzed. A relation between the different mission concepts and the performances to be obtained with enhanced aerodynamics was established to identify which of the four platform concepts could perform as a commercial platform to guarantee the use for different applications.Design and development of a hyper-thermal atomic oxygen wind tunnel facility
http://hdl.handle.net/2117/330366
Design and development of a hyper-thermal atomic oxygen wind tunnel facility
Oiko, Vitor; Roberts, Peter C.E; Edmonson, Steve; García-Almiñana, Daniel; Rodríguez Donaire, Silvia; Sureda Anfres, Miquel
A hyper-thermal orbital aerodynamics test facility is described. The Rarefied Orbital Aerodynamics Research facility(ROAR)is a dedicated apparatus designedto simulate the atmospheric flow in very low Earth orbits(VLEO) to investigate the impact different material properties have on gas-surface interactions, and determine the aerodynamic properties of materials from the reemitted gas distribution. The main characteristics observed in VLEO to be reproduced are the free molecular flow regime and the flux of oxygen atoms at orbital velocities impinging on the spacecraft surface. This is accomplished by combining an ultra-high vacuum system with a hyper-thermal oxygen atoms generator. Materials performance will be assessed via a scattering experiment in which an atomic oxygen beam is incident on the surface of a test sample and the scattered species are recorded by mass spectrometers. The design of theexperiment is discussed, from the specification of the vacuum components to the generation of oxygen atoms and their detection.
2020-10-16T12:04:24ZOiko, VitorRoberts, Peter C.EEdmonson, SteveGarcía-Almiñana, DanielRodríguez Donaire, SilviaSureda Anfres, MiquelA hyper-thermal orbital aerodynamics test facility is described. The Rarefied Orbital Aerodynamics Research facility(ROAR)is a dedicated apparatus designedto simulate the atmospheric flow in very low Earth orbits(VLEO) to investigate the impact different material properties have on gas-surface interactions, and determine the aerodynamic properties of materials from the reemitted gas distribution. The main characteristics observed in VLEO to be reproduced are the free molecular flow regime and the flux of oxygen atoms at orbital velocities impinging on the spacecraft surface. This is accomplished by combining an ultra-high vacuum system with a hyper-thermal oxygen atoms generator. Materials performance will be assessed via a scattering experiment in which an atomic oxygen beam is incident on the surface of a test sample and the scattered species are recorded by mass spectrometers. The design of theexperiment is discussed, from the specification of the vacuum components to the generation of oxygen atoms and their detection.Inductive Plasma Thruster (IPT) for an Atmosphere-Breathing Electric Propulsion System: design and set in operation
http://hdl.handle.net/2117/330353
Inductive Plasma Thruster (IPT) for an Atmosphere-Breathing Electric Propulsion System: design and set in operation
Romano, Francesco; Herdrich, Georg; Roberts, Peter C.E; García-Almiñana, Daniel; Rodríguez Donaire, Silvia; Sureda Anfres, Miquel
Challenging space missions include those at very low orbits, where the atmosphere is source of significant drag on a satellite. Therefore, an efficient dragcompensation propulsion system is required to extend the mission lifetime. One solution is Atmosphere-Breathing Electric Propulsion (ABEP), a system that collects atmospheric particles and directly uses them as propellant for an electric thruster, therefore minimizing the requirement of limited propellant availability. The system is theoretically applicable to any celestial body with atmosphere. This would enable new mission types due to the new altitude ranges available for continuous orbiting. Challenging is also the presence of reactive chemical species, such as atomic oxygen in Earth orbit, erosion source of (not only) the propulsion system components, i.e. acceleration grids, electrodes and discharge channels of conventional EP systems such as RIT and HET. IRS is developing within the DISCOVERER project an intake and a thruster for an ABEP system. This paper, deals with the design of novel contact-less RF thruster, the inductive plasma thruster (IPT) based on a novel antenna design.
2020-10-16T08:12:23ZRomano, FrancescoHerdrich, GeorgRoberts, Peter C.EGarcía-Almiñana, DanielRodríguez Donaire, SilviaSureda Anfres, MiquelChallenging space missions include those at very low orbits, where the atmosphere is source of significant drag on a satellite. Therefore, an efficient dragcompensation propulsion system is required to extend the mission lifetime. One solution is Atmosphere-Breathing Electric Propulsion (ABEP), a system that collects atmospheric particles and directly uses them as propellant for an electric thruster, therefore minimizing the requirement of limited propellant availability. The system is theoretically applicable to any celestial body with atmosphere. This would enable new mission types due to the new altitude ranges available for continuous orbiting. Challenging is also the presence of reactive chemical species, such as atomic oxygen in Earth orbit, erosion source of (not only) the propulsion system components, i.e. acceleration grids, electrodes and discharge channels of conventional EP systems such as RIT and HET. IRS is developing within the DISCOVERER project an intake and a thruster for an ABEP system. This paper, deals with the design of novel contact-less RF thruster, the inductive plasma thruster (IPT) based on a novel antenna design.RF Helicon-based Plasma Thruster (IPT): Design, Set-up, and First Ignition
http://hdl.handle.net/2117/330247
RF Helicon-based Plasma Thruster (IPT): Design, Set-up, and First Ignition
Romano, Francesco; Chan, Yung-An; Herdrich, Georg; García-Almiñana, Daniel; Rodríguez Donaire, Silvia; Sureda Anfres, Miquel; García Berenguer, Marina
To extend missions lifetime at very low altitudes, an efficient propulsion system is requiredto compensate for aerodynamic drag. One solution is Atmosphere-Breathing Electric Propulsion (ABEP). It collects atmospheric particles to be used as propellant for an electric thruster. The system ideally nullifies the requirement of onboard propellant storage.An ABEP system can be applied to any celestial bodywith atmosphere(Mars, Venus, Titan, etc.), enabling new mission at low altitude ranges for longer times. Challenging is operation of the thruster on reactive chemical species, such as atomic oxygen, that is highly presentin low Earth orbit,as theycause erosion of (not only) propulsion system components, i.e. acceleration grids, electrodes, neutralizers, and discharge channels of conventional EP systems.For this reason, a contactless plasma thruster is developed:the RF helicon-based plasma thruster (IPT). The paper describes the thruster design, implementation, and first ignition tests. The thruster implements a novel antenna called the birdcage antenna that is implemented for decades in magnetic resonance imaging (MRI)machines. The design is supported by the simulation tool XFdtd®. The IPT is aided by an externally applied static magnetic field that provides the boundary condition for the helicon wave formation within the plasma discharge.The antenna working principle allows to minimize losses in the electric circuit and provides, together with the applied magnetic field, acceleration ofa quasi-neutral plasma plume.
2020-10-14T14:28:42ZRomano, FrancescoChan, Yung-AnHerdrich, GeorgGarcía-Almiñana, DanielRodríguez Donaire, SilviaSureda Anfres, MiquelGarcía Berenguer, MarinaTo extend missions lifetime at very low altitudes, an efficient propulsion system is requiredto compensate for aerodynamic drag. One solution is Atmosphere-Breathing Electric Propulsion (ABEP). It collects atmospheric particles to be used as propellant for an electric thruster. The system ideally nullifies the requirement of onboard propellant storage.An ABEP system can be applied to any celestial bodywith atmosphere(Mars, Venus, Titan, etc.), enabling new mission at low altitude ranges for longer times. Challenging is operation of the thruster on reactive chemical species, such as atomic oxygen, that is highly presentin low Earth orbit,as theycause erosion of (not only) propulsion system components, i.e. acceleration grids, electrodes, neutralizers, and discharge channels of conventional EP systems.For this reason, a contactless plasma thruster is developed:the RF helicon-based plasma thruster (IPT). The paper describes the thruster design, implementation, and first ignition tests. The thruster implements a novel antenna called the birdcage antenna that is implemented for decades in magnetic resonance imaging (MRI)machines. The design is supported by the simulation tool XFdtd®. The IPT is aided by an externally applied static magnetic field that provides the boundary condition for the helicon wave formation within the plasma discharge.The antenna working principle allows to minimize losses in the electric circuit and provides, together with the applied magnetic field, acceleration ofa quasi-neutral plasma plume.