Publikationen

Buchbeiträge

Jensine Andresen, Octavio A. Chon Torres (Herausgeber),
Extraterrestrial Intelligence: Academic and Societal Implications,
Cambridge Scholars Publishing, 2022, ISBN: 978-1-5275-7727-5

Harald Zaun (Herausgeber),
Expedition ins Sternenmeer,
Perspektiven, Chancen und Risiken einer interstellaren Raumfahrt,
Springer, 2022, ISBN: 978-3-662-63729-6

Ley/Wittmann/Hallmann (Editor),
Handbook of Space Technology,
Wiley-Blackwell , 2009, ISBN: 978-0-470-69739-9,
Chapter 8.4

Ley/Wittmann/Hallmann (Herausgeber),
Handbuch der Raumfahrttechnik,
Carl Hanser Verlag München Wien, 2008, ISBN-10: 3-446-41185-2, 2008,
Kapitel 8.4

Rainer Sandau (principal editor),
International Study on Cost-Effective Earth Observation Missions,
CRC Press, 2006, ISBN-13: 978-0415391368

Konferenzbeiträge, Proceedings

2023

T. Neumann, E. Borschinsky, H. Kayal, J. Männel, C. Riegler, "Kleinsatellitentechnologien zur Beantwortung wissenschaftlicher Fragen in der Extraterrestrik", in Deutscher Luft- und Raumfahrtkongress, Stuttgart, 2023
J. Männel, E. Borschinsky, H. Kayal, T. Neumann, C. Riegler, "Trends und Forschungswünsche in der Extraterrestrik und Ideen für eine nationale Kleinsatellitenmission: Analyse einer Umfrage unter Wissenschaftlern in Deutschland im Rahmen des Satexprojekts", in Deutscher Luft- und Raumfahrtkongress, Stuttgart, 2023
Tobias Kaiser, Dominik Thois, Oleksii Balagurin, Tobias Greiner, Hakan Kayal, Tobias Schwarz, Andreas Maurer, Tobias Herbst, Clemens Riegler, "Attitude-independent calibration of magnetometers in orbit using Particle Swarm Optimization", in 14th IAA Symposium on Small Satellites for Earth Observation, Berlin, 2023
Tobias Greiner, Oleksii Balagurin, Tobias Herbst, Tobias Kaiser, Hakan Kayal, Andreas Maurer, Tobias Schwarz, "SONATE-2 – Using Artificial Intelligence for In-Orbit Image Processing and Anomaly Detection", in 14th IAA Symposium on Small Satellites for Earth Observation, Berlin, 2023

Ältere

O. Balagurin, K. Djebko, G. Fellinger, H. Kayal, A. Schartel, A. Schneider, T. Schwarz, A. Vodopivec und H. Wojtkowiak, „A concept for a nanosatellite mission to demonstrate autonomous system technologies,“ in 11th IAA Symposium on Small Satellites for Earth Observation, Berlin, 2017.
K. Djebko, T. Schwarz, G. Fellinger, H. Kayal, F. Puppe, A. Schartel, A. Vodopivec und H. Wojtkowiak, „A model-based fault detection and root cause identification system for increased autonomy of small satellites,“ in 11th IAA Symposium on Small Satellites for Earth Observation, Berlin, 2017.
H. Kayal, O. Balagurin, K. Djebko, G. Fellinger, F. Puppe, A. Schartel, T. Schwarz, A. Vodopivec und H. Wojtkowiak, „SONATE - A Nano Satellite for the In-Orbit Verification of Autonomous Detection, Planning and Diagnosis Technologies,“ in AIAA Space and Astronautics Forum and Exposition , Long Beach, CA, 2016.
O. Balagurin, G. Fellinger, H. Kayal, T. Schwarz und H. Wojtkowiak, „A Novel Nano Satellite Mission to Demonstrate Autonomous System Technologies,“ in Small Satellites, System & Services Symposium (4S), Valetta, Malta, 2016.
T. Schwarz, O. Balaruin, K. Djebko, G. Fellinger, H. Kayal, F. Puppe, A. Schartel, A. Vodopivec und H. Wojtkowiak, „SONATE Nanosatelliten-Mission zur Erprobung von hochautonomen Nutzlasten,“ in Deutscher Luft- und Raumfahrtkongress, Braunschweig, 2016.
A. Schartel, O. Balagurin, H. Kayal und T. Schwarz, „Ein Micro-Display basierter Sternsimulator für Indoor-Tests miniaturisierter Sternsensoren,“ in Deutscher Luft- und Raumfahrtkongress, Braunschweig, 2016.
T. Schwarz, O. Balagurin, H. Kayal und A. Schartel, „PicoStar - Prototyping of a Star Sensor for Pico-Satellites,“ in 8th Pico- and Nano-Satellite Workshop, Würzburg, 2015.

Artikel, Working Paper

2023[ to top ]

Research on Unidentified Aerial Phenomena at the Julius-Maximilians-University of Würzburg Kayal, Hakan; Greiner, Tobias; Kaiser, Tobias; Oehme, Sebastian (2023). (Vol. Session: Scientific and Technical Advancements in UAP Understanding (Virtual)
- [ Abstract ]
- [ BibTeX ]
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One of the main research topics at the professorship of Astronautics of the Julius-Maximilian University Würzburg (JMUW) is the investigation of Unidentified Aerial Phenomena (UAP) since 2008. The observations of the phenomena for decades, previously known as Unidentified Flying Object (UFO), with their partly very unusual characteristics and the potential threat to air traffic are important reasons to investigate the background of these phenomena. Since a serious part of the reported characteristics obviously could not be clarified even after intensive investigations, UAP is also interesting for science and some of them could point to new phenomena, perhaps previously unknown. However, due to the stigma attached to the UFO phenomenon for more than 74 years, very few scientific investigations and publications have been carried out so far, thus preventing its elucidation. In this paper the activities at the JMUW in UAP research would be explained.

@conference{kayal2023research, abstract = {One of the main research topics at the professorship of Astronautics of the Julius-Maximilian University Würzburg (JMUW) is the investigation of Unidentified Aerial Phenomena (UAP) since 2008. The observations of the phenomena for decades, previously known as Unidentified Flying Object (UFO), with their partly very unusual characteristics and the potential threat to air traffic are important reasons to investigate the background of these phenomena. Since a serious part of the reported characteristics obviously could not be clarified even after intensive investigations, UAP is also interesting for science and some of them could point to new phenomena, perhaps previously unknown. However, due to the stigma attached to the UFO phenomenon for more than 74 years, very few scientific investigations and publications have been carried out so far, thus preventing its elucidation. In this paper the activities at the JMUW in UAP research would be explained.}, author = {Kayal, Hakan and Greiner, Tobias and Kaiser, Tobias and Oehme, Sebastian}, keywords = {myown}, title = {Research on Unidentified Aerial Phenomena at the Julius-Maximilians-University of Würzburg}, volume = {Session: Scientific and Technical Advancements in UAP Understanding (Virtual)}, year = 2023 }

2022[ to top ]

Testing the NVIDIA Jetson Xavier NX Module for the SONATE-2 Nano Satellite Mission Herbst, Tobias; Balagurin, Oleksii; Greiner, Tobias; Kaiser, Tobias; Kayal, Hakan; Maurer, Andreas; Riegler, Clemens; Schwarz, Tobias (2022). (Vol. IAC 2022 congress proceedings) 7.
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
SONATE-2 is a 6U+, LEO CubeSat mission, which will demonstrate the feasibility of in-orbit image processing using neural networks. These networks shall also be trained on-board. Therefore, a powerful computational unit with a small form factor and low power consumption is needed. One possible candidate, the NVIDIA Jetson Xavier NX is analysed and tested for a possible use in this mission. Thus, thermal vacuum chamber tests, total ionizing radiation dose tests, single event effect tests and vibration tests were performed to expose the module to conditions equivalent to space environment present in LEO. The module has been Total Ionizing Dose (TID) tested with a Co-60 source at a dose of 10,krad. Single Event Effect (SEE) testing has been done with protons at energy levels of 30, 50 and 68 MeV. In addition to that, vibration tests have been conducted on acceptance level for a launch with a Soyuz-2 rocket for a containerized CubeSat. The thermal-vacuum tests included an outgassing test and a thermal cycling test with 5 cycles from -30$$^\circ$$C to 90$$^\circ$$C. After the TID tests, the vibration tests and the thermal tests, no damage to the module could be detected. During the outgassing test, a total mass loss of at least 0.08,% was measured. During the SEE tests, two single event effects occurred, of which one caused the device to reboot and another one caused a memory error in the modules eMMC memory. Thus, it is recommended to implement a redundancy strategy for the content of the eMMC memory and operate the device, such that spontaneous reboots do not lead to critical failures.

@conference{noauthororeditor, abstract = {SONATE-2 is a 6U+, LEO CubeSat mission, which will demonstrate the feasibility of in-orbit image processing using neural networks. These networks shall also be trained on-board. Therefore, a powerful computational unit with a small form factor and low power consumption is needed. One possible candidate, the NVIDIA Jetson Xavier NX is analysed and tested for a possible use in this mission. Thus, thermal vacuum chamber tests, total ionizing radiation dose tests, single event effect tests and vibration tests were performed to expose the module to conditions equivalent to space environment present in LEO. The module has been Total Ionizing Dose (TID) tested with a Co-60 source at a dose of 10\,krad. Single Event Effect (SEE) testing has been done with protons at energy levels of 30, 50 and 68 MeV. In addition to that, vibration tests have been conducted on acceptance level for a launch with a Soyuz-2 rocket for a containerized CubeSat. The thermal-vacuum tests included an outgassing test and a thermal cycling test with 5 cycles from -30$^\circ$C to 90$^\circ$C. After the TID tests, the vibration tests and the thermal tests, no damage to the module could be detected. During the outgassing test, a total mass loss of at least 0.08\,\% was measured. During the SEE tests, two single event effects occurred, of which one caused the device to reboot and another one caused a memory error in the modules eMMC memory. Thus, it is recommended to implement a redundancy strategy for the content of the eMMC memory and operate the device, such that spontaneous reboots do not lead to critical failures.}, address = {100 Avenue de Suffren 75015 Paris, France}, author = {Herbst, Tobias and Balagurin, Oleksii and Greiner, Tobias and Kaiser, Tobias and Kayal, Hakan and Maurer, Andreas and Riegler, Clemens and Schwarz, Tobias}, keywords = {redundancy}, pages = 7, publisher = {International Astronautical Federation (IAF)}, title = {Testing the NVIDIA Jetson Xavier NX Module for the SONATE-2 Nano Satellite Mission}, volume = {IAC 2022 congress proceedings}, year = 2022 }
Detection of UAP with a Nano Satellite Reitemeyer, Malte; Weinmann, Felix; Kayal, Hakan in Research on Unidentified Aerial Phenomena (2022).
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@article{https://doi.org/10.25972/opus-26139, author = {Reitemeyer, Malte and Weinmann, Felix and Kayal, Hakan}, journal = {Research on Unidentified Aerial Phenomena}, keywords = {UAP}, publisher = {Universität Würzburg}, title = {Detection of UAP with a Nano Satellite}, year = 2022 }
VELEX: Venus Lightning Experiment Riegler, Clemens; Kayal, Hakan in Raumfahrttechnik und Extraterrestrik (2022).
- [ BibTeX ]
- [ URL ]
@article{https://doi.org/10.25972/opus-28248, author = {Riegler, Clemens and Kayal, Hakan}, journal = {Raumfahrttechnik und Extraterrestrik}, keywords = {Venus}, publisher = {Universität Würzburg}, title = {VELEX: Venus Lightning Experiment}, year = 2022 }
MAPLE: Marsian Autorotation Probe Lander Experiment Riegler, Clemens; Werner, Lennart; Kayal, Hakan in Raumfahrttechnik und Extraterrestrik (2022).
- [ BibTeX ]
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@article{https://doi.org/10.25972/opus-28239, author = {Riegler, Clemens and Werner, Lennart and Kayal, Hakan}, journal = {Raumfahrttechnik und Extraterrestrik}, keywords = {Rotorcraft}, publisher = {Universität Würzburg}, title = {MAPLE: Marsian Autorotation Probe Lander Experiment}, year = 2022 }
MultiView: Koordinierter Sternsensorverbund im TunaCan-Format für CubeSats Neumann, T.; Balagurin, O.; Baldsiefen, D.; Gerling, T.; Kaiser, T.; Kayal, H.; Maurer, A.; Riegler, C.; Schwarz, T. (2022). 7.
- [ Abstract ]
- [ BibTeX ]
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Der Zusammenschluss mehrerer miniaturisierter Sternsensoren bietet in der richtigen Konfiguration eine stark erhöhte Verfügbarkeit an genauen Lagedaten. Das begrenzte Bauvolumen auf einem CubeSat stellt dabei eine Herausforderung dar. Die Verwendung des TunaCan-Slots, verbunden mit dem Einsatz der gegebenen hohen Sensorredundanz, ermöglicht allerdings die Realisierung eines solchen Verbundes, während die Anforderungen im Rahmen einer CubeSat-Mission bleiben. Die internen Komponenten müssen selbständig miteinander arbeiten, um die funktionale Redundanz zu bewerkstelligen. Dazu zählt sowohl die Software als auch die entsprechend entworfene Elektronik. In diesem Paper wird solch ein Konzept ausgearbeitet und die Implementierung aufgeführt. Die interne Arbeitsweise zur Redundanzsteuerung und der Datenverarbeitung wird erläutert und die Validierung zum Einsatz im Orbit in Aussicht gestellt.

@article{neumann2022multiview, abstract = {Der Zusammenschluss mehrerer miniaturisierter Sternsensoren bietet in der richtigen Konfiguration eine stark erhöhte Verfügbarkeit an genauen Lagedaten. Das begrenzte Bauvolumen auf einem CubeSat stellt dabei eine Herausforderung dar. Die Verwendung des TunaCan-Slots, verbunden mit dem Einsatz der gegebenen hohen Sensorredundanz, ermöglicht allerdings die Realisierung eines solchen Verbundes, während die Anforderungen im Rahmen einer CubeSat-Mission bleiben. Die internen Komponenten müssen selbständig miteinander arbeiten, um die funktionale Redundanz zu bewerkstelligen. Dazu zählt sowohl die Software als auch die entsprechend entworfene Elektronik. In diesem Paper wird solch ein Konzept ausgearbeitet und die Implementierung aufgeführt. Die interne Arbeitsweise zur Redundanzsteuerung und der Datenverarbeitung wird erläutert und die Validierung zum Einsatz im Orbit in Aussicht gestellt.}, author = {Neumann, T. and Balagurin, O. and Baldsiefen, D. and Gerling, T. and Kaiser, T. and Kayal, H. and Maurer, A. and Riegler, C. and Schwarz, T.}, keywords = {myown}, pages = 7, publisher = {Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V.}, title = {MultiView: Koordinierter Sternsensorverbund im TunaCan-Format für CubeSats}, year = 2022 }
Erforschung des Unidentified Aerial Phenomena an der JMU Würzburg Kayal, H.; Greiner, T.; Kaiser, T.; Riegler, C. (2022). (Vol. Deutscher Luft- und Raumfahrtkongress 2022) 8.
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
Die Erforschung von unbekannten Himmelsphänomenen, die heute allgemeiner als "Unidentified Aerial Phenomena" (UAP) bezeichnet und früher Unidentified Flying Object (UFO) genannt wurden, haben das Potential zu neuen, bedeutenden wissenschaftlichen Erkenntnissen zu führen, sollte sich herausstellen, dass die Ursachen auf neue, bisher unbekannte Phänomene zurückzuführen sind. Bisher wurden diese Phänomene in der Wissenschaft allerdings kaum beachtet, weshalb es nur wenige wissenschaftlich fundierte Daten und Erkenntnisse dazu gibt. Die bloße Existenz von UAP oder UFO wird spätestens seit den offiziellen Bekanntmachungen im Sommer 2021 in den USA kaum noch in Zweifel gezogen. Die Phänomene zeigen zu einem kleinen, aber nicht zu ignorierenden Teil, sehr ungewöhnliche Eigenschaften wie extreme Flugcharakteristika, die teilweise scheinbar gleichzeitig durch verschiedene Sensoren bestätigt sind. Diese können nicht immer auf herkömmliche Ursachen zurückgeführt werden. Es geht sogar so weit, dass Sie in manchen Fällen scheinbar in Widerspruch zu physikalischen Naturgesetzen stehen. Sollte es sich dabei nicht ausnahmslos um Sensorartefakte, Fehlinterpretationen oder ähnliches handeln, sondern wirklich um physikalische Phänomene oder Objekte, müssten ganz neue Hypothesen und Theorien entwickelt werden. Dies könnte zur Entdeckung von neuen, bisher völlig unbekannten Naturphänomenen oder sogar zu ungeahnten Paradigmenwechsel im Verständnis unserer Welt führen. Nicht komplett auszuschließen wäre darüber hinaus die extraterrestrische Hypothese, wonach die Ursachen der Phänomene teilweise auf Signaturen technologisch fortgeschrittener außerirdischer Intelligenzen zurückzuführen sein könnten. Sollte sich diese Hypothese bewahrheiten, wäre es die bedeutendste Entdeckung der Menschheitsgeschichte mit weitreichenden Folgen für die Wissenschaft und Gesellschaft. Obwohl die Phänomene seit über 70 Jahren beobachtet werden, gibt es aufgrund der Stigmatisierung des Themas an sich, dem Fehlen von begründeten Hypothesen, der nicht Vorhersehbarkeit des Auftretens, der Sicherheitsaspekte und vor allem dem Fehlen einer soliden Datenbasis, kaum wissenschaftliche Untersuchungen. Es ist deswegen unerlässlich, zunächst eine verlässliche Datenbasis zu schaffen, um die Phänomene überhaupt erst untersuchen zu können. An der Professur für Raumfahrttechnik der Julius-Maximilian Universität Würzburg wird seit 2008 an diesem Forschungsschwerpunkt gearbeitet. Der Schwerpunkt liegt auf der Entwicklung und dem Betrieb von neuartigen, dem flüchtigen Problem angepassten, intelligenten Sensorsystemen. Dazu sollen die Daten von verschiedenen Typen von abbildenden und nicht abbildenden Sensoren aus unterschiedlichen Wellenlängenbereichen kombiniert und ausgewertet werden. Einer der Schwerpunkte liegt in der Software, die eine effiziente und KI-gestützte Klassifizierung an den vernetzten Beobachtungsstationen in nahezu Echtzeit ermöglichen und die Falschalarmrate verringern soll. Die an ausgewählten Regionen aufgestellten Beobachtungsstationen können dann in der Folge mit hoher geometrischer, radiometrischer und temporaler Auflösung Daten über das Phänomen liefern, was systematische Analysen ermöglichen soll.

@conference{kayal2022erforschung, abstract = {Die Erforschung von unbekannten Himmelsphänomenen, die heute allgemeiner als "Unidentified Aerial Phenomena" (UAP) bezeichnet und früher Unidentified Flying Object (UFO) genannt wurden, haben das Potential zu neuen, bedeutenden wissenschaftlichen Erkenntnissen zu führen, sollte sich herausstellen, dass die Ursachen auf neue, bisher unbekannte Phänomene zurückzuführen sind. Bisher wurden diese Phänomene in der Wissenschaft allerdings kaum beachtet, weshalb es nur wenige wissenschaftlich fundierte Daten und Erkenntnisse dazu gibt. Die bloße Existenz von UAP oder UFO wird spätestens seit den offiziellen Bekanntmachungen im Sommer 2021 in den USA kaum noch in Zweifel gezogen. Die Phänomene zeigen zu einem kleinen, aber nicht zu ignorierenden Teil, sehr ungewöhnliche Eigenschaften wie extreme Flugcharakteristika, die teilweise scheinbar gleichzeitig durch verschiedene Sensoren bestätigt sind. Diese können nicht immer auf herkömmliche Ursachen zurückgeführt werden. Es geht sogar so weit, dass Sie in manchen Fällen scheinbar in Widerspruch zu physikalischen Naturgesetzen stehen. Sollte es sich dabei nicht ausnahmslos um Sensorartefakte, Fehlinterpretationen oder ähnliches handeln, sondern wirklich um physikalische Phänomene oder Objekte, müssten ganz neue Hypothesen und Theorien entwickelt werden. Dies könnte zur Entdeckung von neuen, bisher völlig unbekannten Naturphänomenen oder sogar zu ungeahnten Paradigmenwechsel im Verständnis unserer Welt führen. Nicht komplett auszuschließen wäre darüber hinaus die extraterrestrische Hypothese, wonach die Ursachen der Phänomene teilweise auf Signaturen technologisch fortgeschrittener außerirdischer Intelligenzen zurückzuführen sein könnten. Sollte sich diese Hypothese bewahrheiten, wäre es die bedeutendste Entdeckung der Menschheitsgeschichte mit weitreichenden Folgen für die Wissenschaft und Gesellschaft. Obwohl die Phänomene seit über 70 Jahren beobachtet werden, gibt es aufgrund der Stigmatisierung des Themas an sich, dem Fehlen von begründeten Hypothesen, der nicht Vorhersehbarkeit des Auftretens, der Sicherheitsaspekte und vor allem dem Fehlen einer soliden Datenbasis, kaum wissenschaftliche Untersuchungen. Es ist deswegen unerlässlich, zunächst eine verlässliche Datenbasis zu schaffen, um die Phänomene überhaupt erst untersuchen zu können. An der Professur für Raumfahrttechnik der Julius-Maximilian Universität Würzburg wird seit 2008 an diesem Forschungsschwerpunkt gearbeitet. Der Schwerpunkt liegt auf der Entwicklung und dem Betrieb von neuartigen, dem flüchtigen Problem angepassten, intelligenten Sensorsystemen. Dazu sollen die Daten von verschiedenen Typen von abbildenden und nicht abbildenden Sensoren aus unterschiedlichen Wellenlängenbereichen kombiniert und ausgewertet werden. Einer der Schwerpunkte liegt in der Software, die eine effiziente und KI-gestützte Klassifizierung an den vernetzten Beobachtungsstationen in nahezu Echtzeit ermöglichen und die Falschalarmrate verringern soll. Die an ausgewählten Regionen aufgestellten Beobachtungsstationen können dann in der Folge mit hoher geometrischer, radiometrischer und temporaler Auflösung Daten über das Phänomen liefern, was systematische Analysen ermöglichen soll.}, address = {Bonn}, author = {Kayal, H. and Greiner, T. and Kaiser, T. and Riegler, C.}, keywords = {UAP}, pages = 8, publisher = {Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V.}, title = {Erforschung des Unidentified Aerial Phenomena an der JMU Würzburg}, volume = {Deutscher Luft- und Raumfahrtkongress 2022}, year = 2022 }
Hardware and Software Redundancy Concepts on-board of SONATE-2 Maurer, Andreas; Balagurin, Oleksii; Greiner, Tobias; Herbst, Tobias; Kaiser, Tobias; Kayal, Hakan; Riegler, Clemens; Schwarz, Tobias (2022). (Vol. IAC 2022 congress proceedings) 11.
- [ Abstract ]
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SONATE-2 is a 6U-CubeSat, which main mission goal is the in-orbit demonstration of a newly developed AI processing platform. Experiments running on this platform include lightening detection, image segmentation and anomaly detection in images taken by the satellite. Thereby, on-board training of neural networks for AI based image processing applications will be demonstrated. Secondary mission objectives include the verification of AOCS components, tests of the ADCS’s target-pointing capabilities and the operation of an amateur radio payload. The SONATE-2 satellite is planned to be launched into a SSO in Q1 2024. par In satellites, redundancy plays a key role due to the lack of hardware-based maintenance availability, but also because of the harsh space environment. Therefore, SONATE-2 consists of two fully redundant 5V and 12V busses which supply the satellite’s subsystems and payloads with the required amount of power. Redundant subsystems are connected to one of the two power busses. In case of a power failure on one of the two busses, the redundant component supplied by the other bus is then still operational. par A key element of the design of SONATE-2 is hardware-based redundancy of the communication subsystem, the ADCS, the OBDH and the AI payload. Each of these subsystems is included multiple times on-board. SONATE-2’s communication subsystem consists of two VHF-, two UHF- and two S-Band transceivers and antennas. The ADCS includes two processing computers and a total of four three-axis magnetometers, four three-axis gyroscopes, six reaction wheel, six magnetorquer and 12 sun sensors. On-board data handling tasks are executed by one of four available OBDH computers. The decision which OBDH is executing the telecommand processing and housekeeping tasks is determined by a software-based role arbitration. Furthermore, the AI-payload which consists of a Nvidia Jetson Xavier NX and four cameras is integrated in the satellite twice. par Each of these subsystems have further built-in software-based redundancy concepts, including fault detection, isolation, and recovery algorithms as well as redundant saved configurations. This paper gives a brief overview of the SONATE-2 mission with the focus on the built-in hardware and software redundancy concepts of the satellite bus and the payloads on SONATE-2.

@conference{maurer2022hardware, abstract = {SONATE-2 is a 6U-CubeSat, which main mission goal is the in-orbit demonstration of a newly developed AI processing platform. Experiments running on this platform include lightening detection, image segmentation and anomaly detection in images taken by the satellite. Thereby, on-board training of neural networks for AI based image processing applications will be demonstrated. Secondary mission objectives include the verification of AOCS components, tests of the ADCS’s target-pointing capabilities and the operation of an amateur radio payload. The SONATE-2 satellite is planned to be launched into a SSO in Q1 2024. \par In satellites, redundancy plays a key role due to the lack of hardware-based maintenance availability, but also because of the harsh space environment. Therefore, SONATE-2 consists of two fully redundant 5V and 12V busses which supply the satellite’s subsystems and payloads with the required amount of power. Redundant subsystems are connected to one of the two power busses. In case of a power failure on one of the two busses, the redundant component supplied by the other bus is then still operational. \par A key element of the design of SONATE-2 is hardware-based redundancy of the communication subsystem, the ADCS, the OBDH and the AI payload. Each of these subsystems is included multiple times on-board. SONATE-2’s communication subsystem consists of two VHF-, two UHF- and two S-Band transceivers and antennas. The ADCS includes two processing computers and a total of four three-axis magnetometers, four three-axis gyroscopes, six reaction wheel, six magnetorquer and 12 sun sensors. On-board data handling tasks are executed by one of four available OBDH computers. The decision which OBDH is executing the telecommand processing and housekeeping tasks is determined by a software-based role arbitration. Furthermore, the AI-payload which consists of a Nvidia Jetson Xavier NX and four cameras is integrated in the satellite twice. \par Each of these subsystems have further built-in software-based redundancy concepts, including fault detection, isolation, and recovery algorithms as well as redundant saved configurations. This paper gives a brief overview of the SONATE-2 mission with the focus on the built-in hardware and software redundancy concepts of the satellite bus and the payloads on SONATE-2.}, address = {100 Avenue de Suffren 75015 Paris, France}, author = {Maurer, Andreas and Balagurin, Oleksii and Greiner, Tobias and Herbst, Tobias and Kaiser, Tobias and Kayal, Hakan and Riegler, Clemens and Schwarz, Tobias}, keywords = {redundancy}, month = {sep}, pages = 11, publisher = {International Astronautical Federation (IAF)}, title = {Hardware and Software Redundancy Concepts on-board of SONATE-2}, volume = {IAC 2022 congress proceedings}, year = 2022 }
Towards Utilization of Autorotation in Interplanetary Exploration on the example of Venus Riegler, Clemens; Kayal, Hakan (2022). (Vol. IAC 2022 congress proceedings)
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- [ URL ]
Humanity is striving to be an interplanetary species more than ever before. Therefore, not only launching but also landing is a key capability for any future spacecraft. Right now, the state of the art is either landing by parachute or a propulsive approach. Parachutes are hardly ever reused, hence not a good choice for reusable vehicles. Propulsive landings do provide reusability but demand fuel and oxidizer, which might only be safe to use for a limited amount of time, e.g. due to temperature constraints. A viable solution that combines controllability, reusability and does not require any fuel is available in the form of autorotation. This is not a new technology in itself. Helicopters use it for landing in case of an engine failure. However, in the context of space flight, this technology has hardly been investigated. This paper shall present a number of possibilities of theoretical utilizations of an autorotation system for a Venus mission. The focus is on a number of different sized vehicles with different purposes that utilize autorotation. Furthermore the vehicles will be evaluated upon their deployment method. A mission can be a small atmospheric probe and deployed by a bigger mission or it can be a lander with direct re-entry. It is important to understand the advantages and disadvantages of autorotation in these different scenarios. Furthermore, comparison of the viability of the missions upon different performance parameters is made. This includes TRL, overall complexity and especially in comparison with other decelerators. The goal is to create a baseline. It shows where missions might be able to benefit by the utilization of autorotation. The possible limits of the technology are also outlined in this paper.

@conference{noauthororeditor, abstract = {Humanity is striving to be an interplanetary species more than ever before. Therefore, not only launching but also landing is a key capability for any future spacecraft. Right now, the state of the art is either landing by parachute or a propulsive approach. Parachutes are hardly ever reused, hence not a good choice for reusable vehicles. Propulsive landings do provide reusability but demand fuel and oxidizer, which might only be safe to use for a limited amount of time, e.g. due to temperature constraints. A viable solution that combines controllability, reusability and does not require any fuel is available in the form of autorotation. This is not a new technology in itself. Helicopters use it for landing in case of an engine failure. However, in the context of space flight, this technology has hardly been investigated. This paper shall present a number of possibilities of theoretical utilizations of an autorotation system for a Venus mission. The focus is on a number of different sized vehicles with different purposes that utilize autorotation. Furthermore the vehicles will be evaluated upon their deployment method. A mission can be a small atmospheric probe and deployed by a bigger mission or it can be a lander with direct re-entry. It is important to understand the advantages and disadvantages of autorotation in these different scenarios. Furthermore, comparison of the viability of the missions upon different performance parameters is made. This includes TRL, overall complexity and especially in comparison with other decelerators. The goal is to create a baseline. It shows where missions might be able to benefit by the utilization of autorotation. The possible limits of the technology are also outlined in this paper.}, address = {100 Avenue de Suffren 75015 Paris, France}, author = {Riegler, Clemens and Kayal, Hakan}, keywords = {venus}, publisher = {International Astronautical Federation (IAF)}, title = {Towards Utilization of Autorotation in Interplanetary Exploration on the example of Venus}, volume = {IAC 2022 congress proceedings}, year = 2022 }

2020[ to top ]

Accurate estimation of relative atmospheric density error on the example of uncertain geomagnetic activity information Schiemenz, Fabian; Utzmann, Jens; Kayal, Hakan in Advances in Space Research (2020). 65(1) 251–270.
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
Errors in neutral atmospheric density are the dominant contributor to unrealistic orbital state-vector covariances in low Earth orbits (LEO). Density uncertainty is caused by model-uncertainty at spatial scales below and within the model resolution, as well as input-uncertainty of the environmental parameters supplied to the semi-empirical atmospheric model. The paper at hand provides multiple contributions. First, analytic equations are derived to estimate the relative density error due to an input parameter uncertainty in any of the environmental parameters supplied to the model. Second, it is shown on the example of uncertain geomagnetic activity information, how to compute the required inputs to facilitate the accurate estimation of the relative density error. A clamped cubic splining approach for the conversion from geomagnetic amplitude (ap) to the kp index is postulated to perform this uncertainty propagation, as other algorithms were found unsuitable for this task. Results of numerical simulations with three popular semi-empirical models are provided to validate the set of derived equations. It is found that geomagnetic input uncertainty is especially important to consider in case of low global geomagnetic activity. The findings seamlessly integrate with prior work by the authors to perform density-uncertainty considering orbit estimation.

@article{SCHIEMENZ2020251, abstract = {Errors in neutral atmospheric density are the dominant contributor to unrealistic orbital state-vector covariances in low Earth orbits (LEO). Density uncertainty is caused by model-uncertainty at spatial scales below and within the model resolution, as well as input-uncertainty of the environmental parameters supplied to the semi-empirical atmospheric model. The paper at hand provides multiple contributions. First, analytic equations are derived to estimate the relative density error due to an input parameter uncertainty in any of the environmental parameters supplied to the model. Second, it is shown on the example of uncertain geomagnetic activity information, how to compute the required inputs to facilitate the accurate estimation of the relative density error. A clamped cubic splining approach for the conversion from geomagnetic amplitude (ap) to the kp index is postulated to perform this uncertainty propagation, as other algorithms were found unsuitable for this task. Results of numerical simulations with three popular semi-empirical models are provided to validate the set of derived equations. It is found that geomagnetic input uncertainty is especially important to consider in case of low global geomagnetic activity. The findings seamlessly integrate with prior work by the authors to perform density-uncertainty considering orbit estimation.}, author = {Schiemenz, Fabian and Utzmann, Jens and Kayal, Hakan}, journal = {Advances in Space Research}, keywords = {LEO}, number = 1, pages = {251-270}, title = {Accurate estimation of relative atmospheric density error on the example of uncertain geomagnetic activity information}, volume = 65, year = 2020 }

2019[ to top ]

Model-Based Fault Detection and Diagnosis for Spacecraft with an Application for the SONATE Triple Cube Nano-Satellite Djebko, Kirill; Puppe, Frank; Kayal, Hakan in Aerospace (2019). 6(10) 105.
- [ BibTeX ]
- [ URL ]
@article{Djebko_2019, author = {Djebko, Kirill and Puppe, Frank and Kayal, Hakan}, journal = {Aerospace}, keywords = {myown}, month = {sep}, number = 10, pages = 105, publisher = {{MDPI} {AG}}, title = {Model-Based Fault Detection and Diagnosis for Spacecraft with an Application for the {SONATE} Triple Cube Nano-Satellite}, volume = 6, year = 2019 }
Hyper-SETI – A New Way of Searching for Extraterrestrial Intelligence Kayal, Hakan (2019). (Vol. IAC 2019 congress proceedings)
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
In this paper a new way of searching for extraterrestrial communication is proposed by using a unique combination of a new search strategy and modern technologies such as machine learning, which is called “HYPER-SETI”. HYPER-SETI presumes, that extraterrestrial civilizations, who are technologically more advanced than ours do not communicate by means which is used by the classical SETI instruments, namely search for artificial and decodable signals in different wavelengths of the electromagnetic spectrum. Effective communication is obviously not possible (even though principally possible) because of the limiting speed of electromagnetic waves. This may be the main reason, why we don’t “hear” or “see” anything up to now. The absence of such an intelligent signal is not necessarily due to the non-existence of intelligent life but simply due to the unsuited technology we use for the searching. Our communication devices are simply incompatible for an effective interstellar communication. Even if there are some other civilizations, who use similar techniques for communications, the chances to find and even communicate with them are small, at least due to the huge distances. HYPER-SETI takes a new approach, not repeating, what did not find any results up to now. It rather starts with the question, which type of technology would be necessary for effective interstellar communication and what is maybe more important, would it be possible for us to detect signs or side effects of such a new and fantastic technology? Although, we obviously don’t have such a technology yet, we can start with describing, which properties it should have and see, if there is a possibility to observe traces of such communications between others, even if we are not able to directly interfere with it. So, we do not necessarily have to detect or understand the communication itself, but at the beginning it might be sufficient to discover side effects or accompanying phenomena, which are observable to us in a conventional way using conventional sensors but advanced information technologies. As this type of communication technology has to be unknown to us, attendant circumstances must appear also unknown or unexplainable to us, otherwise it was something we already know. Thus HYPER-SETI proposes to start intentionally searching for strange and unknown phenomena’s within the electromagnetic spectrum, which might be signs of communication, instead of searching for the communication itself. This typ of search can nowadays be supported by methods of machine learning and artificial intelligence.

@conference{kayal2019hyperseti, abstract = {In this paper a new way of searching for extraterrestrial communication is proposed by using a unique combination of a new search strategy and modern technologies such as machine learning, which is called “HYPER-SETI”. HYPER-SETI presumes, that extraterrestrial civilizations, who are technologically more advanced than ours do not communicate by means which is used by the classical SETI instruments, namely search for artificial and decodable signals in different wavelengths of the electromagnetic spectrum. Effective communication is obviously not possible (even though principally possible) because of the limiting speed of electromagnetic waves. This may be the main reason, why we don’t “hear” or “see” anything up to now. The absence of such an intelligent signal is not necessarily due to the non-existence of intelligent life but simply due to the unsuited technology we use for the searching. Our communication devices are simply incompatible for an effective interstellar communication. Even if there are some other civilizations, who use similar techniques for communications, the chances to find and even communicate with them are small, at least due to the huge distances. HYPER-SETI takes a new approach, not repeating, what did not find any results up to now. It rather starts with the question, which type of technology would be necessary for effective interstellar communication and what is maybe more important, would it be possible for us to detect signs or side effects of such a new and fantastic technology? Although, we obviously don’t have such a technology yet, we can start with describing, which properties it should have and see, if there is a possibility to observe traces of such communications between others, even if we are not able to directly interfere with it. So, we do not necessarily have to detect or understand the communication itself, but at the beginning it might be sufficient to discover side effects or accompanying phenomena, which are observable to us in a conventional way using conventional sensors but advanced information technologies. As this type of communication technology has to be unknown to us, attendant circumstances must appear also unknown or unexplainable to us, otherwise it was something we already know. Thus HYPER-SETI proposes to start intentionally searching for strange and unknown phenomena’s within the electromagnetic spectrum, which might be signs of communication, instead of searching for the communication itself. This typ of search can nowadays be supported by methods of machine learning and artificial intelligence.}, address = {100 Avenue de Suffren 75015 Paris, France}, author = {Kayal, Hakan}, keywords = {myown}, publisher = {International Astronautical Federation (IAF)}, title = {Hyper-SETI – A New Way of Searching for Extraterrestrial Intelligence}, volume = {IAC 2019 congress proceedings}, year = 2019 }
On Improving an Embedded Solution for the ASAP Autonomous Planning System Krainovic, Anselm; Balagurin, Oleksii; Kayal, Hakan; Maurer, Andreas (2019). (Vol. IAC 2019 congress proceedings)
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
ASAP is an autonomous sensor and planning system developed at the Professorship of Space Technology at the University of Würzburg. The main components have been integrated into the SONATE nanosatellite, which is scheduled for launch in 2019. Equipped with a highspeed optical sensor, ASAP allows the detection and classification of transient events, like meteors entering the Earth’s atmosphere. The planning system is a highly configurable component providing higher autonomy by generating command lists based on the actual satellite state. This allows fast reactions to events, which would not be possible in the classical mission operations. ASAP currently uses FPGA technology. It enables the image processing to work at very high framerates, whereas it limits the available computational resources and frequency of the softcore processor the planning system runs on. Moreover, the scheduling unit of the planning system uses a branch and bound algorithm, whereat each iteration consists of solving a linear program using the Simplex algorithm. Due to the complexity of the algorithm, scheduling is computationally quite expensive. In the scope of this paper we present a possible alternative novel approach to overcome the above limitations by implementing the planning system on a dedicated microcontroller, and more importantly, by developing an improved scheduling algorithm. To do so, we consider sparse matrices as efficient data structures, LU factorizations, revised simplex algorithms and further mathematical concepts. We are closing by evaluating the improvements on the basis of the general concept, as well as typical use case scenarios, and by discussing further possibilities to improve the planning system for an autonomous mission operation.

@conference{krainovic2019improving, abstract = {ASAP is an autonomous sensor and planning system developed at the Professorship of Space Technology at the University of Würzburg. The main components have been integrated into the SONATE nanosatellite, which is scheduled for launch in 2019. Equipped with a highspeed optical sensor, ASAP allows the detection and classification of transient events, like meteors entering the Earth’s atmosphere. The planning system is a highly configurable component providing higher autonomy by generating command lists based on the actual satellite state. This allows fast reactions to events, which would not be possible in the classical mission operations. ASAP currently uses FPGA technology. It enables the image processing to work at very high framerates, whereas it limits the available computational resources and frequency of the softcore processor the planning system runs on. Moreover, the scheduling unit of the planning system uses a branch and bound algorithm, whereat each iteration consists of solving a linear program using the Simplex algorithm. Due to the complexity of the algorithm, scheduling is computationally quite expensive. In the scope of this paper we present a possible alternative novel approach to overcome the above limitations by implementing the planning system on a dedicated microcontroller, and more importantly, by developing an improved scheduling algorithm. To do so, we consider sparse matrices as efficient data structures, LU factorizations, revised simplex algorithms and further mathematical concepts. We are closing by evaluating the improvements on the basis of the general concept, as well as typical use case scenarios, and by discussing further possibilities to improve the planning system for an autonomous mission operation.}, address = {100 Avenue de Suffren 75015 Paris, France}, author = {Krainovic, Anselm and Balagurin, Oleksii and Kayal, Hakan and Maurer, Andreas}, keywords = {nanosatellite}, publisher = {International Astronautical Federation (IAF)}, title = {On Improving an Embedded Solution for the ASAP Autonomous Planning System}, volume = {IAC 2019 congress proceedings}, year = 2019 }

2018[ to top ]

Preparing SONATE for Autonomous Control Through ASAP Rapp, Thomas; Balagurin, Oleksii; Baumann, Tom; Kayal, Hakan; Krainovic, Anselm; Schwarz, Tobias; Wojtkowiak, Harald in IAC 2018 congress proceedings (2018). (Vol. 69th International Astronautical Congress (IAC)
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
SONATE is a 3U-CubeSat technology demonstrator mission for highly autonomous payloads currently under development at the Professorship of Space Technology at the University of Würzburg and scheduled for launch in 2019. One of SONATE’s primary objectives is to verify the key elements of the autonomous sensor and planning system (ASAP) on-orbit. The general benefits of the high degree of autonomy implemented by ASAP are twofold. Firstly, it allows new satellite applications where fast response to external events (e.g. meteor entry into Earth´s atmosphere for Earth Observation Missions) is required. Secondly, it reduces the overall mission costs by moving workload from the operator to the satellite itself. To complete the verification of ASAP in a closed loop manner, ASAP needs to take over control of the satellite by manipulating SONATE’s active command list. However, the demonstration of the highly autonomous functions shall not put extra risk on the SONATE mission as a whole and especially the satellite’s other payloads. In order to combine the high degree of autonomy required for the verification of ASAP with the common requirements of a technology demonstrator mission accommodating also other payloads, special measures must be taken. Those measures, which are presented in detail with this paper, affect the verification process of ASAP itself, the onboard data handling system (OBDH), and the mission operations of SONATE. They include different check-out levels for the autonomous functionalities of ASAP, protective measures of the OBDH against unauthorized attempts of ASAP to control the satellite, new concepts for the mission planning process on ground, and directives for the mission operations on ground. The different check-out levels range from LEOP procedures common for every payload, through experiments during which ASAP runs but the plans are not executed, to finally full autonomous control of SONATE through ASAP. The protection of the OBDH is implemented by dedicated states in which the OBDH accepts commands from ASAP as well as a whitelist of commands to be accepted. Both for the mission planning process and mission operations on ground, new concepts had to be developed for this transition from classical operations towards full autonomy. We finally conclude that the set of those measures is sufficient to combine both worlds of classical operations and the increasing on-board autonomy for satellites and that thus they allow the on-orbit verification of ASAP without putting extra risk onto the SONATE mission.

@conference{rapp2018preparing, abstract = {SONATE is a 3U-CubeSat technology demonstrator mission for highly autonomous payloads currently under development at the Professorship of Space Technology at the University of Würzburg and scheduled for launch in 2019. One of SONATE’s primary objectives is to verify the key elements of the autonomous sensor and planning system (ASAP) on-orbit. The general benefits of the high degree of autonomy implemented by ASAP are twofold. Firstly, it allows new satellite applications where fast response to external events (e.g. meteor entry into Earth´s atmosphere for Earth Observation Missions) is required. Secondly, it reduces the overall mission costs by moving workload from the operator to the satellite itself. To complete the verification of ASAP in a closed loop manner, ASAP needs to take over control of the satellite by manipulating SONATE’s active command list. However, the demonstration of the highly autonomous functions shall not put extra risk on the SONATE mission as a whole and especially the satellite’s other payloads. In order to combine the high degree of autonomy required for the verification of ASAP with the common requirements of a technology demonstrator mission accommodating also other payloads, special measures must be taken. Those measures, which are presented in detail with this paper, affect the verification process of ASAP itself, the onboard data handling system (OBDH), and the mission operations of SONATE. They include different check-out levels for the autonomous functionalities of ASAP, protective measures of the OBDH against unauthorized attempts of ASAP to control the satellite, new concepts for the mission planning process on ground, and directives for the mission operations on ground. The different check-out levels range from LEOP procedures common for every payload, through experiments during which ASAP runs but the plans are not executed, to finally full autonomous control of SONATE through ASAP. The protection of the OBDH is implemented by dedicated states in which the OBDH accepts commands from ASAP as well as a whitelist of commands to be accepted. Both for the mission planning process and mission operations on ground, new concepts had to be developed for this transition from classical operations towards full autonomy. We finally conclude that the set of those measures is sufficient to combine both worlds of classical operations and the increasing on-board autonomy for satellites and that thus they allow the on-orbit verification of ASAP without putting extra risk onto the SONATE mission.}, author = {Rapp, Thomas and Balagurin, Oleksii and Baumann, Tom and Kayal, Hakan and Krainovic, Anselm and Schwarz, Tobias and Wojtkowiak, Harald}, journal = {IAC 2018 congress proceedings}, keywords = {myown}, month = {october}, publisher = {International Astronautical Federation (IAF)}, title = {Preparing SONATE for Autonomous Control Through ASAP}, volume = {69th International Astronautical Congress (IAC)}, year = 2018 }
Next Level Autonomous Nanosatellite Operations Kayal, Hakan; Balagurin, Oleksii; Djebko, Kirill; Fellinger, Gerhard; Puppe, Frank; Seipel, Dietmar; Serdar, Saliha; Schneider, Alexander; Schwarz, Tobias; Wojtkowiak, Harald in SpaceOps Conferences (2018). (Vol. 2018 SpaceOps Conference)
- [ BibTeX ]
- [ URL ]
@conference{kayal2018level, author = {Kayal, Hakan and Balagurin, Oleksii and Djebko, Kirill and Fellinger, Gerhard and Puppe, Frank and Seipel, Dietmar and Serdar, Saliha and Schneider, Alexander and Schwarz, Tobias and Wojtkowiak, Harald}, booktitle = {SpaceOps Conferences}, keywords = {leo}, publisher = {American Institute of Aeronautics and Astronautics, Inc.}, title = {Next Level Autonomous Nanosatellite Operations}, volume = {2018 SpaceOps Conference}, year = 2018 }

2017[ to top ]

A High-Level Decision Support System for Nanosatellites Kayal, Hakan; Seipel, Dietmar; Serdar, Saliha (2017). (Vol. IAC 2017 congress proceedings)
- [ BibTeX ]
- [ URL ]
@conference{kayal2017highlevel, address = {100 Avenue de Suffren 75015 Paris, France}, author = {Kayal, Hakan and Seipel, Dietmar and Serdar, Saliha}, keywords = {nanosatellite}, publisher = {International Astronautical Federation (IAF)}, title = {A High-Level Decision Support System for Nanosatellites}, volume = {IAC 2017 congress proceedings}, year = 2017 }
A Nanosatellite Mission Concept for Optical SETI Kayal, Hakan; Balagurin, Oleksii; Schneider, Alexander (2017). (Vol. IAC 2017 congress proceedings)
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
In view of recent discoveries of the significantly increasing number of extrasolar planets in possibly habitable zones and knowledge about extreme circumstances under which life could exist, it appears to be more and more likely that signs of life outside Earth could be detected soon. If and when his happens, the next logical question will be if intelligent lifeforms may exist and moreover if they are trying to communicate with other civilizations. Under these circumstances, the search for extraterrestrial intelligences (SETI) seems to be natural more than ever, although the search of more than 50 years in radio wavelengths has not delivered a positive sign yet. One of the possible ways to study potential signals coming from intelligent extraterrestrial lifeforms can be to analyze the optical spectrum, which is usually called OSETI (Optical Search for Extraterrestrial Intelligence). OSETI is also already conducted by several institutions using ground-based facilities on Earth by using an array of photomultiplier tubes. But such observations are limited due to the atmosphere. Therefore, a possible way to overcome the disadvantage of the atmospheric influence could be the use of a dedicated satellite for OSETI in an earth orbit. Since such a satellite mission would be obviously very expensive, it is worth to be investigated if there is the possibility to reduce the cost of such a mission by utilizing a nanosatellite concept. In recent years, nanosatellites of the order of 1 to 20 kg have reached a high state of maturity and are becoming a more and more useful tool for several applications, ranging from communications to scientific experiments and observations. The basic idea of this study is to answer the question if a dedicated nanosatellite could be used for OSETI. The study is conducted by the Interdisciplinary Research Center for Extraterrestrial Studies (IFEX) of the University of Würzburg. The results of the study will be presented at the conference and described in a report.

@conference{kayal2017nanosatellite, abstract = {In view of recent discoveries of the significantly increasing number of extrasolar planets in possibly habitable zones and knowledge about extreme circumstances under which life could exist, it appears to be more and more likely that signs of life outside Earth could be detected soon. If and when his happens, the next logical question will be if intelligent lifeforms may exist and moreover if they are trying to communicate with other civilizations. Under these circumstances, the search for extraterrestrial intelligences (SETI) seems to be natural more than ever, although the search of more than 50 years in radio wavelengths has not delivered a positive sign yet. One of the possible ways to study potential signals coming from intelligent extraterrestrial lifeforms can be to analyze the optical spectrum, which is usually called OSETI (Optical Search for Extraterrestrial Intelligence). OSETI is also already conducted by several institutions using ground-based facilities on Earth by using an array of photomultiplier tubes. But such observations are limited due to the atmosphere. Therefore, a possible way to overcome the disadvantage of the atmospheric influence could be the use of a dedicated satellite for OSETI in an earth orbit. Since such a satellite mission would be obviously very expensive, it is worth to be investigated if there is the possibility to reduce the cost of such a mission by utilizing a nanosatellite concept. In recent years, nanosatellites of the order of 1 to 20 kg have reached a high state of maturity and are becoming a more and more useful tool for several applications, ranging from communications to scientific experiments and observations. The basic idea of this study is to answer the question if a dedicated nanosatellite could be used for OSETI. The study is conducted by the Interdisciplinary Research Center for Extraterrestrial Studies (IFEX) of the University of Würzburg. The results of the study will be presented at the conference and described in a report.}, address = {100 Avenue de Suffren 75015 Paris, France}, author = {Kayal, Hakan and Balagurin, Oleksii and Schneider, Alexander}, keywords = {optics}, publisher = {International Astronautical Federation (IAF)}, title = {A Nanosatellite Mission Concept for Optical SETI}, volume = {IAC 2017 congress proceedings}, year = 2017 }

2015[ to top ]

Autonome Beobachtung von Transient Lunar Phenomena Mohn, H.; Balagurin, O.; Kayal, H. (2015).
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
Transient Lunar Phenomena (TLP) sind noch nicht gänzlich geklärte Leuchtphänomene auf dem Mond. Um den Ursprung dieser Phänomene zu erforschen, fehlt es an Quantität und Qualität der Daten. Eine für diesen Zweck neu entwickelte Beobachtungseinheit (Moonspy) kann autonom hochwertige Beobachtungen von Anomalien auf dem Mond aufzeichnen. Durch den regelmäßigen Einsatz ist es so möglich in Zukunft mehr wertvolle Daten über TLP zu erhalten. Das Moonspy System konnte in mehrfachen Feldversuchen erfolgreich getestet werden. Dieses neue Werkzeug der TLP Forschung soll hier vorgestellt werden.

@misc{mohn2015autonome, abstract = {Transient Lunar Phenomena (TLP) sind noch nicht gänzlich geklärte Leuchtphänomene auf dem Mond. Um den Ursprung dieser Phänomene zu erforschen, fehlt es an Quantität und Qualität der Daten. Eine für diesen Zweck neu entwickelte Beobachtungseinheit (Moonspy) kann autonom hochwertige Beobachtungen von Anomalien auf dem Mond aufzeichnen. Durch den regelmäßigen Einsatz ist es so möglich in Zukunft mehr wertvolle Daten über TLP zu erhalten. Das Moonspy System konnte in mehrfachen Feldversuchen erfolgreich getestet werden. Dieses neue Werkzeug der TLP Forschung soll hier vorgestellt werden.}, author = {Mohn, H. and Balagurin, O. and Kayal, H.}, keywords = {myown}, publisher = {Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn}, title = {Autonome Beobachtung von Transient Lunar Phenomena}, type = {text}, year = 2015 }

2014[ to top ]

Methods and Systems for Increasing Autonomy of Earth Observation Satellites Balagurin, Oleksii; Fellinger, Gerhard; Fischer, Wendelin; Kayal, Hakan; Wojtkowiak, Harald in Small Satellites Systems and Services - The 4S Symposium (2014).
- [ BibTeX ]
@inproceedings{balagurin2014methods, author = {Balagurin, Oleksii and Fellinger, Gerhard and Fischer, Wendelin and Kayal, Hakan and Wojtkowiak, Harald}, booktitle = {Small Satellites Systems and Services - The 4S Symposium}, keywords = {myown}, month = {may}, organization = {ESA & CNES}, title = {Methods and Systems for Increasing Autonomy of Earth Observation Satellites}, year = 2014 }
STAR SENSOR SOLUTIONS FOR PICO AND NANOSATELLITE Balagurin, Oleksii; Fischer, Wendelin; Kayal, Hakan; Wojtkowiak, Harald in Small Satellites Systems and Services - The 4S Symposium (2014).
- [ BibTeX ]
@inproceedings{balagurin2014sensor, author = {Balagurin, Oleksii and Fischer, Wendelin and Kayal, Hakan and Wojtkowiak, Harald}, booktitle = {Small Satellites Systems and Services - The 4S Symposium}, keywords = {myown}, month = {may}, organization = {ESA & CNES}, title = {STAR SENSOR SOLUTIONS FOR PICO AND NANOSATELLITE}, year = 2014 }
Hardwarenahe Softwarelösungen für Miniaturisierte Sternsensoren Fischer, Wendelin; Balagurin, Oleksii; Kayal, Hakan; Wojtkowiak, Harald in 63. Deutscher Luft- und Raumfahrtkongress (2014).
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
Zur genauen Lagebestimmung von Raumfahrtsystemen sind Sternsensoren meist unabdingbar. Da die Anforderungen an die Lagekenntnis auch im Kleinsatelliten- und Cubesatbereich immer weiter steigen, müssen vermehrt neue Möglichkeiten gefunden werden bestehende Konzepte an die Anforderungen dieser Satellitenklassen anzupassen oder neue zu entwickeln. Im folgenden Beitrag wird die Entwicklung eines neuartigen Sternerkennungsalgorithmus vorgestellt, der eine sehr viel schnellere und effizientere Lagebestimmung als herkömmlichen Verfahren ermöglicht. Hierdurch soll die präzise Lagebestimmung im Kleinsatellitenbereich weiter vorangebracht werden. Die Implementierung dieses Algorithmus auf dem neuen Sternsensor Nanostar wird ebenfalls beleuchtet. Dieser wird momentan an der Universität Würzburg entwickelt und soll bis 2016 vollständig qualifiziert sein.

@inproceedings{fischer2014hardwarenahe, abstract = {Zur genauen Lagebestimmung von Raumfahrtsystemen sind Sternsensoren meist unabdingbar. Da die Anforderungen an die Lagekenntnis auch im Kleinsatelliten- und Cubesatbereich immer weiter steigen, müssen vermehrt neue Möglichkeiten gefunden werden bestehende Konzepte an die Anforderungen dieser Satellitenklassen anzupassen oder neue zu entwickeln. Im folgenden Beitrag wird die Entwicklung eines neuartigen Sternerkennungsalgorithmus vorgestellt, der eine sehr viel schnellere und effizientere Lagebestimmung als herkömmlichen Verfahren ermöglicht. Hierdurch soll die präzise Lagebestimmung im Kleinsatellitenbereich weiter vorangebracht werden. Die Implementierung dieses Algorithmus auf dem neuen Sternsensor Nanostar wird ebenfalls beleuchtet. Dieser wird momentan an der Universität Würzburg entwickelt und soll bis 2016 vollständig qualifiziert sein.}, author = {Fischer, Wendelin and Balagurin, Oleksii and Kayal, Hakan and Wojtkowiak, Harald}, booktitle = {63. Deutscher Luft- und Raumfahrtkongress}, keywords = {myown}, month = {September}, organization = {Deutsche Gesellschaft für Luft- und Raumfahrt}, title = {Hardwarenahe Softwarelösungen für Miniaturisierte Sternsensoren}, year = 2014 }
ASAP: Autonomous onboard mission planning Wojtkowiak, Harald; Balagurin, Oleksii; Fellinger, Gerhard; Fischer, Wendelin; Garcia Fernandez, Borja; Kayal, Hakan in 65th International Astronautical Congress (2014).
- [ BibTeX ]
- [ URL ]
@inproceedings{wojtkowiak2014autonomous, author = {Wojtkowiak, Harald and Balagurin, Oleksii and Fellinger, Gerhard and Fischer, Wendelin and Garcia Fernandez, Borja and Kayal, Hakan}, booktitle = {65th International Astronautical Congress}, keywords = {myown}, number = {IAC-14,B6,2,2,x22347}, organization = {International Astronautical Federation}, title = {ASAP: Autonomous onboard mission planning}, year = 2014 }

2013[ to top ]

TechnoSat-A Nanosatellite Mission for On-Orbit Technology Demonstration Barschke, Merlin; Ballheimer, Walter; Dornburg, Lars; Noack, Daniel; Brieß, Klaus; Adirim, Harry; Pilz, Norbert; Kayal, Hakan; Balagurin, Oleksii; Wojtkowiak, Harald; Nitzschke, Christian in 27th Annual AIAA/USU Conference on Small Satellites (2013).
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
In the last 25 years, TU Berlin developed, built, launched and operated a number of university class satellites. Throughout these missions, emphasis was placed on developing technologies for Earth remote sensing, communication and attitude determination and control. The nanosatellite mission TechnoSat has the primary objective to provide on-orbit demonstration capability for novel nanosatellite technologies and components. The satellite carries five main payloads: A separation system for nanosatellites, a hatch mechanism designed for protection and on-orbit calibration of infrared cameras, a fluid dynamic actuator for energy efficient attitude control, an extendable boom system that is employed for gravity gradient stabilisation and STELLA, a miniaturised star tracker. The secondary mission objective of TechnoSat is the on-orbit verification of the novel adaptive nanosatellite bus TUBiX20 (TU Berlin innovative neXt generation 20 kg nanosatellite bus). TechnoSat is scheduled to be launched in Q4 2014.

@inproceedings{barschke2013technosat, abstract = {In the last 25 years, TU Berlin developed, built, launched and operated a number of university class satellites. Throughout these missions, emphasis was placed on developing technologies for Earth remote sensing, communication and attitude determination and control. The nanosatellite mission TechnoSat has the primary objective to provide on-orbit demonstration capability for novel nanosatellite technologies and components. The satellite carries five main payloads: A separation system for nanosatellites, a hatch mechanism designed for protection and on-orbit calibration of infrared cameras, a fluid dynamic actuator for energy efficient attitude control, an extendable boom system that is employed for gravity gradient stabilisation and STELLA, a miniaturised star tracker. The secondary mission objective of TechnoSat is the on-orbit verification of the novel adaptive nanosatellite bus TUBiX20 (TU Berlin innovative neXt generation 20 kg nanosatellite bus). TechnoSat is scheduled to be launched in Q4 2014.}, author = {Barschke, Merlin and Ballheimer, Walter and Dornburg, Lars and Noack, Daniel and Brie{\ss}, Klaus and Adirim, Harry and Pilz, Norbert and Kayal, Hakan and Balagurin, Oleksii and Wojtkowiak, Harald and Nitzschke, Christian}, booktitle = {27th Annual AIAA/USU Conference on Small Satellites}, keywords = {myown}, number = {Technical Session XI: Around the Corner}, publisher = {AIAA/Utah State University}, title = {TechnoSat-A Nanosatellite Mission for On-Orbit Technology Demonstration}, year = 2013 }
ADIA: A Novel Onboard Failure Diagnostic System for Nanosatellites Fellinger, Gerhard; Dietrich, Georg; Fette, Georg; Kayal, Hakan; Puppe, Frank; Schneider, Volker; Wojtkowiak, Harald in 64th International Astronautical Congress (2013). (Vol. 4, 3)
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
Spacecraft failure analysis is often a time-consuming process which requires increased attention from ground personnel. Since operations expenditures represent a major part of overall satellite mission cost, efficient assignment of resources, especially when it comes to as weighty a cost factor as manpower, is critical. This is especially true for small-scale satellites which are often operated by research groups with limited means. Also, ground-based error source isolation by operators implies that due to limited contact windows, real-time diagnosis is usually out of the question, hence losing valuable time when quick reactions to critical failures are necessary. Moreover, the onset of failures looming for several days or weeks cannot be easily predicted by human operators who are by and large not good at trend-analyzing large amounts of data, especially if mutually interdependent time series are involved. Thus, the capability to analyze errors in real-time onboard a satellite is desirable as it can help cut costs and reduce mission failure risk. In order to provide such capabilities, the development of a new autonomous failure diagnostic system called ADIA (Autonomous Diagnostic System for Satellites) has started at the University of Würzburg which is funded through the German Aerospace Center (FKZ 50RM1231) by the Federal Ministry of Economics and Technology (BMWi). The goal is to develop an onboard diagnostic software which is capable of detecting errors, isolating them with respect to their cause as well as trend analysis of spacecraft telemetry data for the prediction of future subsystem malfunctions. The system consists of two functionally intertwined components. One is a set of diagnostic algorithms with an interface to the satellite’s TTC system. The second is a satellite simulator software which has two functions: on the one hand, it serves as a “telemetry generator” in the context of ADIA’s development process, providing the diagnostic core with raw data during system testing and fine-tuning. On the other hand, the simulator can itself be integrated into the diagnostic component, thus making ADIA a model-based analysis tool. Internal states of the simulator can be compared with the state of the actual satellite in order to derive hypotheses on the nature of an emerging error. The focus of this paper lies on the discussion of ADIA’s requirements, the basic functional concept as well as the workings of the diagnostic core. Additionally, a brief discussion of the nanosatellite to be modeled as part of the development process is included.

@inproceedings{fellinger2013novel, abstract = {Spacecraft failure analysis is often a time-consuming process which requires increased attention from ground personnel. Since operations expenditures represent a major part of overall satellite mission cost, efficient assignment of resources, especially when it comes to as weighty a cost factor as manpower, is critical. This is especially true for small-scale satellites which are often operated by research groups with limited means. Also, ground-based error source isolation by operators implies that due to limited contact windows, real-time diagnosis is usually out of the question, hence losing valuable time when quick reactions to critical failures are necessary. Moreover, the onset of failures looming for several days or weeks cannot be easily predicted by human operators who are by and large not good at trend-analyzing large amounts of data, especially if mutually interdependent time series are involved. Thus, the capability to analyze errors in real-time onboard a satellite is desirable as it can help cut costs and reduce mission failure risk. In order to provide such capabilities, the development of a new autonomous failure diagnostic system called ADIA (Autonomous Diagnostic System for Satellites) has started at the University of Würzburg which is funded through the German Aerospace Center (FKZ 50RM1231) by the Federal Ministry of Economics and Technology (BMWi). The goal is to develop an onboard diagnostic software which is capable of detecting errors, isolating them with respect to their cause as well as trend analysis of spacecraft telemetry data for the prediction of future subsystem malfunctions. The system consists of two functionally intertwined components. One is a set of diagnostic algorithms with an interface to the satellite’s TTC system. The second is a satellite simulator software which has two functions: on the one hand, it serves as a “telemetry generator” in the context of ADIA’s development process, providing the diagnostic core with raw data during system testing and fine-tuning. On the other hand, the simulator can itself be integrated into the diagnostic component, thus making ADIA a model-based analysis tool. Internal states of the simulator can be compared with the state of the actual satellite in order to derive hypotheses on the nature of an emerging error. The focus of this paper lies on the discussion of ADIA’s requirements, the basic functional concept as well as the workings of the diagnostic core. Additionally, a brief discussion of the nanosatellite to be modeled as part of the development process is included.}, author = {Fellinger, Gerhard and Dietrich, Georg and Fette, Georg and Kayal, Hakan and Puppe, Frank and Schneider, Volker and Wojtkowiak, Harald}, booktitle = {64th International Astronautical Congress}, keywords = {myown}, organization = {International Astronautical Federation}, title = {ADIA: A Novel Onboard Failure Diagnostic System for Nanosatellites}, volume = {IAC-13,B4,3,10,x17926}, year = 2013 }
ASAP: Increasing the autonomy of small satellites Wojtkowiak, Harald; Balagurin, Oleksii; Fellinger, Gerhard; Kayal, Hakan in 9th IAA Symposium on Small Satellites for Earth Observation (2013).
- [ BibTeX ]
@inproceedings{wojtkowiak2013increasing, author = {Wojtkowiak, Harald and Balagurin, Oleksii and Fellinger, Gerhard and Kayal, Hakan}, booktitle = {9th IAA Symposium on Small Satellites for Earth Observation}, journal = {9th IAA Symposium on Small Satellites for Earth Observation}, keywords = {myown}, number = {IAA-B9-1109P}, organization = {International Academy of Astronautics}, title = {ASAP: Increasing the autonomy of small satellites}, year = 2013 }
ASAP: AUTONOMOUS DYNAMIC SCHEDULING FOR SMALL SATELLITES Wojtkowiak, Harald; Balagurin, Oleksii; Fellinger, Gerhard; Kayal, Hakan in 64th International Astronautical Congress (2013). (Vol. 4, 3)
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
Usually planning of satellite missions is done on ground by an expert team. Activities have to be prioritized; telecommand lists have to be generated according to time-based procedures and sent to the satellite for execution. In consequence of this method expenses for operations are a major part of the overall satellite mission cost because of the usually intense involvement of humans in the planning and operations processes. Additionally, doing it this way makes it impossible to react on special short-time events such as volcanic eruptions or fires. To improve the process of mission planning, the development of a new autonomous imaging system with an integrated autonomous planning system has been started at the University of Wuerzburg which is funded through the German Aerospace Center (FKZ 50RM1208) by the Federal Ministry of Economics and Technology (BMWi). The aim is to use such a system on board of nano satellites in the future to enable autonomous fast time responses to short-lived optical phenomena. Furthermore the system can relieve the On-Board-Computer (OBC) of the satellite by providing scheduling capacities and mechanism. The main functionality of our new satellite system is twofold. On one hand, it uses its optical system to autonomously detect, classify and track (in the field of view) interesting objects or phenomena like meteors or lightning in the Earth´s atmosphere. In the context of our project, this is called “Autonomous Sensing (AS)”. On the other hand, it provides the capability and means to schedule satellite operation procedures. This feature is called “Autonomous Planning (AP)”. Combined, these acronyms form the project's name ASAP. The main feature is that both functionalities work autonomously. The focus of this paper lies on the scheduling system of ASAP. It has to manage activities and resources. One or several resources can be grouped to one hardware platform on which activities can be executed. Activities and resources can be distinguished in internal ones and external ones. Internal activities and resources are provided by ASAP and can be independently scheduled. For example the “Autonomous Sensing” functionality of ASAP is fully accomplished by internal activities and resources. External activities and resources can be registered in ASAP in order to be integrated into the scheduling process. This sort of operation requires some kind of communication. For this case ASAP offers a special interface to bind external components into the scheduling mechanism.

@inproceedings{wojtkowiak2013autonomous, abstract = {Usually planning of satellite missions is done on ground by an expert team. Activities have to be prioritized; telecommand lists have to be generated according to time-based procedures and sent to the satellite for execution. In consequence of this method expenses for operations are a major part of the overall satellite mission cost because of the usually intense involvement of humans in the planning and operations processes. Additionally, doing it this way makes it impossible to react on special short-time events such as volcanic eruptions or fires. To improve the process of mission planning, the development of a new autonomous imaging system with an integrated autonomous planning system has been started at the University of Wuerzburg which is funded through the German Aerospace Center (FKZ 50RM1208) by the Federal Ministry of Economics and Technology (BMWi). The aim is to use such a system on board of nano satellites in the future to enable autonomous fast time responses to short-lived optical phenomena. Furthermore the system can relieve the On-Board-Computer (OBC) of the satellite by providing scheduling capacities and mechanism. The main functionality of our new satellite system is twofold. On one hand, it uses its optical system to autonomously detect, classify and track (in the field of view) interesting objects or phenomena like meteors or lightning in the Earth´s atmosphere. In the context of our project, this is called “Autonomous Sensing (AS)”. On the other hand, it provides the capability and means to schedule satellite operation procedures. This feature is called “Autonomous Planning (AP)”. Combined, these acronyms form the project's name ASAP. The main feature is that both functionalities work autonomously. The focus of this paper lies on the scheduling system of ASAP. It has to manage activities and resources. One or several resources can be grouped to one hardware platform on which activities can be executed. Activities and resources can be distinguished in internal ones and external ones. Internal activities and resources are provided by ASAP and can be independently scheduled. For example the “Autonomous Sensing” functionality of ASAP is fully accomplished by internal activities and resources. External activities and resources can be registered in ASAP in order to be integrated into the scheduling process. This sort of operation requires some kind of communication. For this case ASAP offers a special interface to bind external components into the scheduling mechanism.}, author = {Wojtkowiak, Harald and Balagurin, Oleksii and Fellinger, Gerhard and Kayal, Hakan}, booktitle = {64th International Astronautical Congress}, keywords = {myown}, organization = {International Astronautical Federation}, title = {ASAP: AUTONOMOUS DYNAMIC SCHEDULING FOR SMALL SATELLITES}, volume = {IAC-13,B4,3,3,x18999}, year = 2013 }
AN AUTONOMOUS IMAGING SYSTEM WITH MISSION PLANNING CAPABILITY Balagurin, Oleksii; Fischer, Wendelin; Kayal, Hakan; Wojtkowiak, Harald in 62. Deutscher Luft- und Raumfahrtkongress (2013).
- [ BibTeX ]
@inproceedings{balagurin2013autonomous, author = {Balagurin, Oleksii and Fischer, Wendelin and Kayal, Hakan and Wojtkowiak, Harald}, booktitle = {62. Deutscher Luft- und Raumfahrtkongress}, keywords = {myown}, month = {September}, organization = {Deutsche Gesellschaft für Luft- und Raumfahrt}, title = {AN AUTONOMOUS IMAGING SYSTEM WITH MISSION PLANNING CAPABILITY}, year = 2013 }
The BayKoSM Project: Technologies for Swarm Missions Freimann, Andreas; Schmidt, Marco; Schilling, Klaus; Graciano, Joao; Fellinger, Gerhard; Kayal, Hakan; Spies, Peter; Zessin, Henrik; Henkel, Patrick; Gerhard, Tjorven; Reichel, Florian; Rummelhagen, Mirko; Marszalek, Michael; Bollert, Reinhard in 5th International Conference on Spacecraft Formation Flying Missions and Technologies (2013).
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
The BayKoSM project is a cooperation of several universities and companies in Bavaria, funded by the Bavarian government. The aim of the project is the development of key technologies for swarms of mobile vehicles. These swarms consist of either pico satellites or uninhabited aerial vehicles (UAVs). The paper describes the corresponding technologies and how they are used within the scope of BayKoSM for intelligent swarm behavior.

@inproceedings{freimann2013baykosm, abstract = {The BayKoSM project is a cooperation of several universities and companies in Bavaria, funded by the Bavarian government. The aim of the project is the development of key technologies for swarms of mobile vehicles. These swarms consist of either pico satellites or uninhabited aerial vehicles (UAVs). The paper describes the corresponding technologies and how they are used within the scope of BayKoSM for intelligent swarm behavior.}, author = {Freimann, Andreas and Schmidt, Marco and Schilling, Klaus and Graciano, Joao and Fellinger, Gerhard and Kayal, Hakan and Spies, Peter and Zessin, Henrik and Henkel, Patrick and Gerhard, Tjorven and Reichel, Florian and Rummelhagen, Mirko and Marszalek, Michael and Bollert, Reinhard}, booktitle = {5th International Conference on Spacecraft Formation Flying Missions and Technologies}, keywords = {myown}, month = {may}, organization = {German Space Operations Center of DLR}, title = {The BayKoSM Project: Technologies for Swarm Missions}, year = 2013 }
ASAP: AUTONOMY THROUGH ON-BOARD PLANNING Wojtkowiak, Harald; Balagurin, Oleksii; Fellinger, Gerhard; Kayal, Hakan in 6th International Conference on Recent Advances in Space Technologies (RAST) (2013).
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
Usually a satellite is entirely controlled from ground. Its tasks are planned in advance by a satellite operations team using specialized scheduling software. When the orbiting satellite enters the transmission range of the ground station, communication is possible, and a newly generated plan (if required) can be uploaded and executed in due time. Although this approach is well-established and has been used for decades, it has some major drawbacks. It binds resources (e.g. personal staff, communication links, etc.) and prohibits fast reactions to transient events, due to the required change of the currently active plan. In the traditional approach, the changes can only be achieved by transmitting a new plan from the ground station to the satellite. This communication imposes time delays which are not acceptable for fast reactions and responses. A way to overcome this problem is to equip the satellite with an autonomous decision-making system which is able to alter the operation plan onboard the satellite. The department of Computer Science VIII of the University of Wuerzburg is currently developing such a system named ASAP and will present it in this paper. The focus lies on the interaction between ASAP and the OnBoard-Computer of the satellite.

@inproceedings{wojtkowiak2013autonomy, abstract = {Usually a satellite is entirely controlled from ground. Its tasks are planned in advance by a satellite operations team using specialized scheduling software. When the orbiting satellite enters the transmission range of the ground station, communication is possible, and a newly generated plan (if required) can be uploaded and executed in due time. Although this approach is well-established and has been used for decades, it has some major drawbacks. It binds resources (e.g. personal staff, communication links, etc.) and prohibits fast reactions to transient events, due to the required change of the currently active plan. In the traditional approach, the changes can only be achieved by transmitting a new plan from the ground station to the satellite. This communication imposes time delays which are not acceptable for fast reactions and responses. A way to overcome this problem is to equip the satellite with an autonomous decision-making system which is able to alter the operation plan onboard the satellite. The department of Computer Science VIII of the University of Wuerzburg is currently developing such a system named ASAP and will present it in this paper. The focus lies on the interaction between ASAP and the OnBoard-Computer of the satellite.}, author = {Wojtkowiak, Harald and Balagurin, Oleksii and Fellinger, Gerhard and Kayal, Hakan}, booktitle = {6th International Conference on Recent Advances in Space Technologies (RAST)}, keywords = {myown}, organization = {AIAA American Institute of Aeronautics and Astronautics}, title = {ASAP: AUTONOMY THROUGH ON-BOARD PLANNING}, year = 2013 }

2012[ to top ]

VALIDATION AND QUALIFICATION OF A CMOS BASED MINIATURE STAR TRACKER FOR SMALL SATELLITES Balagurin, Oleksii; Kayal, Hakan; Wojtkowiak, Harald in Small Satellites Systems and Services - The 4S Symposium (2012).
- [ BibTeX ]
@inproceedings{balagurin2012validation, author = {Balagurin, Oleksii and Kayal, Hakan and Wojtkowiak, Harald}, booktitle = {Small Satellites Systems and Services - The 4S Symposium}, keywords = {myown}, month = {June}, organization = {ESA & CNES}, title = {VALIDATION AND QUALIFICATION OF A CMOS BASED MINIATURE STAR TRACKER FOR SMALL SATELLITES}, year = 2012 }
ASAP: A NOVEL AUTONOMOUS IMAGE SENSOR FOR EVENT DETECTION AND ON BOARD PLANNING SYSTEM Kayal, Hakan; Balagurin, Oleksii; Wojtkowiak, Harald in Small Satellites Systems and Services - The 4S Symposium (2012).
- [ BibTeX ]
@inproceedings{kayal2012novel, author = {Kayal, Hakan and Balagurin, Oleksii and Wojtkowiak, Harald}, booktitle = {Small Satellites Systems and Services - The 4S Symposium}, keywords = {myown}, organization = {ESA & CNES}, title = {ASAP: A NOVEL AUTONOMOUS IMAGE SENSOR FOR EVENT DETECTION AND ON BOARD PLANNING SYSTEM}, year = 2012 }
STELLA - Miniatur-Sternsensor für Pico- und Nanosatelliten Kayal, Hakan in 61. Deutscher Luft- und Raumfahrtkongress (2012).
- [ BibTeX ]
@inproceedings{kayal2012stella, author = {Kayal, Hakan}, booktitle = {61. Deutscher Luft- und Raumfahrtkongress}, keywords = {myown}, organization = {Deutsche Gesellschaft für Luft- und Raumfahrt}, title = {STELLA - Miniatur-Sternsensor für Pico- und Nanosatelliten}, year = 2012 }
ASAP – AUTONOMER BILDSENSOR UND PLANUNGSSYSTEM FÜR NANOSATELLITEN Kayal, Hakan; Balagurin, Oleksii; Wojtkowiak, Harald in 61. Deutscher Luft- und Raumfahrtkongress (2012).
- [ BibTeX ]
@inproceedings{kayal2012autonomer, author = {Kayal, Hakan and Balagurin, Oleksii and Wojtkowiak, Harald}, booktitle = {61. Deutscher Luft- und Raumfahrtkongress}, keywords = {myown}, organization = {Deutsche Gesellschaft für Luft- und Raumfahrt}, title = {ASAP – AUTONOMER BILDSENSOR UND PLANUNGSSYSTEM FÜR NANOSATELLITEN}, year = 2012 }
ASAP – A Sensor System for Autonomous Event Detection and on Board Planning Kayal, Hakan; Balagurin, Oleksii; Wojtkowiak, Harald in 63rd International Astronautical Congress (2012).
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
Traditionally the operations planning is done on ground. User requirements are compiled, put into a priority list and telecommand lists are generated based on predefined procedures. All these planning activities are often done a few days before the commands are uplinked to the satellites, where they are executed at the intended point of time. This well established procedure has the drawback, that one can not react to transient events in the environment which may occur temporarily and might be of interest such as geysers on planets or moons, volcano eruption, fires or fireballs. Additionally the classical planning activities on ground require a significant amount of human resources, which results in high operations cost. One possible way to reduce the disadvantages of classical operations approach is to shift the planning task to the satellite. In order to be able to detect interesting event as mentioned above, the system must be capable of continuously observing the environment of interest and look for predefined features in the sensor data. A second system must then reorganize the on board command list to adapt to the new situation as soon as a interesting feature or event is detected. Within the frame of the ASAP project it is planned to develop such a system containing a image sensor, a processor for the image data and a planning system. The system will be suitable to be operated in the environment of a nano satellite. The project is funded by the German Aerospace Center, DLR (FKZ 50RM1208). The paper will describe the system motivation, the first system concept.

@inproceedings{kayal2012sensor, abstract = {Traditionally the operations planning is done on ground. User requirements are compiled, put into a priority list and telecommand lists are generated based on predefined procedures. All these planning activities are often done a few days before the commands are uplinked to the satellites, where they are executed at the intended point of time. This well established procedure has the drawback, that one can not react to transient events in the environment which may occur temporarily and might be of interest such as geysers on planets or moons, volcano eruption, fires or fireballs. Additionally the classical planning activities on ground require a significant amount of human resources, which results in high operations cost. One possible way to reduce the disadvantages of classical operations approach is to shift the planning task to the satellite. In order to be able to detect interesting event as mentioned above, the system must be capable of continuously observing the environment of interest and look for predefined features in the sensor data. A second system must then reorganize the on board command list to adapt to the new situation as soon as a interesting feature or event is detected. Within the frame of the ASAP project it is planned to develop such a system containing a image sensor, a processor for the image data and a planning system. The system will be suitable to be operated in the environment of a nano satellite. The project is funded by the German Aerospace Center, DLR (FKZ 50RM1208). The paper will describe the system motivation, the first system concept.}, author = {Kayal, Hakan and Balagurin, Oleksii and Wojtkowiak, Harald}, booktitle = {63rd International Astronautical Congress}, keywords = {myown}, number = {IAC-12,B4,3,2,x13917}, organization = {International Astronautical Federation}, title = {ASAP – A Sensor System for Autonomous Event Detection and on Board Planning}, year = 2012 }

2011[ to top ]

TEST AND PERFORMANCE ANALYSIS OF THE NEW STAR TRACKER STELLA Balagurin, Oleksii; Kayal, Hakan; Harald, Wojtkowiak in 60. Deutscher Luft- und Raumfahrtkongress (2011).
- [ BibTeX ]
@inproceedings{balagurin2011performance, author = {Balagurin, Oleksii and Kayal, Hakan and Harald, Wojtkowiak}, booktitle = {60. Deutscher Luft- und Raumfahrtkongress}, keywords = {myown}, month = {September}, organization = {Deutsche Gesellschaft für Luft- und Raumfahrt}, title = {TEST AND PERFORMANCE ANALYSIS OF THE NEW STAR TRACKER STELLA}, year = 2011 }
STELLA - A New Small Star Tracker for Pico and Nano Satellites Balagurin, Oleksii; Kayal, Hakan; Wojtkowiak, Harald in 8th IAA Symposium on Small Satellites for Earth Observation (2011).
- [ BibTeX ]
@inproceedings{balagurin2011stella, author = {Balagurin, Oleksii and Kayal, Hakan and Wojtkowiak, Harald}, booktitle = {8th IAA Symposium on Small Satellites for Earth Observation}, keywords = {myown}, month = {April}, organization = {International Academy of Astronautics}, title = {STELLA - A New Small Star Tracker for Pico and Nano Satellites}, year = 2011 }
A NOVEL APS STAR TRACKER FOR PICO- AND NANO- SATELLITES Wojtkowiak, Harald; Balagurin, Oleksii; Kayal, Hakan in 62nd International Astronautical Congress (2011).
- [ Abstract ]
- [ BibTeX ]
- [ URL ]
STELLA is a miniature star tracker for pico and nano satellites developed at the University Würzburg under financial support of DLR (FKZ 50RM0901). The star tracker features small dimensions and weight as well as low power consumption and fulfills therewith major boundary conditions and requirements of small satellites missions. This paper presents the abilities of STELLA and shows how they contribute to the overall satellite system. The paper focuses on three mayor topics: Mechanics: The paper shows and describes the core and optics of the camera and how it can be integrated into a small satellite system. Further on, the star tracker has been subjected to a full qualification program which includes thermal-vacuum, shock, vibrations and radiation tests and therefore the results will be presented. Electrics/Electronics: This part contains the different logic chips which are used in STELLA and how they communicate and work with each others. Especially the data bus, which is used for (image) data transmission, will be introduced. One special feature is the partial hardware redundancy of the power and main logic system. It can be either controlled by the On-Board-Controller (OBC) of the satellite or works completely autonomous. Software: Through its special Telecommand/Telemetry – Interface it can be adapted to different system conditions and allows access to all sub modules like memory manager, image sensor control or star recognition and attitude determination. The heart of the software is the star recognition and attitude determination program. It works together with the basic software which grants access to different resources like memory, communication busses or the image sensor itself. The software update function allows alternating the program code for all logic devices in order to adapt the behavior of STELLA. Even applications which are different to star recognition and attitude determination are possible with a suitable software update. Finally, the paper will show a listing of all essential parameters and abilities, which are proofed through tests and measurements in laboratory environment as well as field tests. Summarized it can be said, that STELLA is a new star tracker, which enables through it low mass, power and dimensions the usage in pico- and nano-satellites.

@inproceedings{wojtkowiak2011novel, abstract = {STELLA is a miniature star tracker for pico and nano satellites developed at the University Würzburg under financial support of DLR (FKZ 50RM0901). The star tracker features small dimensions and weight as well as low power consumption and fulfills therewith major boundary conditions and requirements of small satellites missions. This paper presents the abilities of STELLA and shows how they contribute to the overall satellite system. The paper focuses on three mayor topics: Mechanics: The paper shows and describes the core and optics of the camera and how it can be integrated into a small satellite system. Further on, the star tracker has been subjected to a full qualification program which includes thermal-vacuum, shock, vibrations and radiation tests and therefore the results will be presented. Electrics/Electronics: This part contains the different logic chips which are used in STELLA and how they communicate and work with each others. Especially the data bus, which is used for (image) data transmission, will be introduced. One special feature is the partial hardware redundancy of the power and main logic system. It can be either controlled by the On-Board-Controller (OBC) of the satellite or works completely autonomous. Software: Through its special Telecommand/Telemetry – Interface it can be adapted to different system conditions and allows access to all sub modules like memory manager, image sensor control or star recognition and attitude determination. The heart of the software is the star recognition and attitude determination program. It works together with the basic software which grants access to different resources like memory, communication busses or the image sensor itself. The software update function allows alternating the program code for all logic devices in order to adapt the behavior of STELLA. Even applications which are different to star recognition and attitude determination are possible with a suitable software update. Finally, the paper will show a listing of all essential parameters and abilities, which are proofed through tests and measurements in laboratory environment as well as field tests. Summarized it can be said, that STELLA is a new star tracker, which enables through it low mass, power and dimensions the usage in pico- and nano-satellites.}, author = {Wojtkowiak, Harald and Balagurin, Oleksii and Kayal, Hakan}, booktitle = {62nd International Astronautical Congress}, keywords = {myown}, number = {IAC-11,C1,6,7,x10267}, organization = {International Astronautical Federation}, title = {A NOVEL APS STAR TRACKER FOR PICO- AND NANO- SATELLITES}, year = 2011 }

2010[ to top ]

STELLA Konzeption und Aufbau eines Sternsensor für Pico- und Nanosatelliten Wojtkowiak, Harald; Balagurin, Oleksii; Kayal, Hakan in ILA-Workshop „Pico- und Nanosatellitenaktivitäten in Deutschland“ (2010).
- [ BibTeX ]
@inproceedings{wojtkowiak2010stella, author = {Wojtkowiak, Harald and Balagurin, Oleksii and Kayal, Hakan}, booktitle = {ILA-Workshop „Pico- und Nanosatellitenaktivitäten in Deutschland“}, keywords = {myown}, organization = {Deutsche Gesellschaft für Luft- und Raumfahrt}, title = {STELLA Konzeption und Aufbau eines Sternsensor für Pico- und Nanosatelliten}, year = 2010 }
RW-1 the Worldwide Smallest Commercial, Flight Proven Reaction Wheel for Pico and Nano Satellites - Fields of Operation and Flight Results Roemer, S.; Stoltz, S.; Baumann, F.; Kayal, H. in Small Satellites Systems and Services - The 4S Symposium (2010).
- [ BibTeX ]
@inproceedings{roemer2010worldwide, author = {Roemer, S. and Stoltz, S. and Baumann, F. and Kayal, H.}, booktitle = {Small Satellites Systems and Services - The 4S Symposium}, keywords = {myown}, organization = {ESA & CNES}, title = {RW-1 the Worldwide Smallest Commercial, Flight Proven Reaction Wheel for Pico and Nano Satellites - Fields of Operation and Flight Results}, year = 2010 }

Ältere

Kayal H.
Autonomous Detection of Objects in Low Earth Orbit by a Nano Satellite Constellation
IAC-09.A6.1.10, 60th International Astronautical Congress (IAC'09), Daejeon, Korea, October 2009

Kayal H.
A Nano Satellite Constellation for Detection of Objects in Earth Orbit
4th International Conference on Recent Advances in Space Technologies (RAST 2009), Istanbul, Turkey, June 2009

Kayal H., Brieß, K.
Autonomous Detection and Observation of the Transient Lunar Phenomenon by a Satellite Constellation
IAC-08-A3.2.INT15, 59th International Astronautical Congress (IAC'08), Glasgow, Scotland, October 2008

Kayal H., Baumann, F., Brieß, K.,
BeeSat – A pico satellite of TU Berlin for the In-orbit verification of miniaturised wheels
IAC-08-B4.4.B10, 59th International Astronautical Congress (IAC'08), Glasgow, Scotland, October 2008

Kayal, H.
A Nano Satellite Mission for Autonomous Detection and Observation of the Transient Lunar Phenomenon
Proceedings of the international conference on Small Satellites, New Missions and New Technologies, Istanbul, Turkey, June 2008

Nohka, F. Baumann, F., Brieß, K., Kayal, H.
Konzept eines orbitalen Sensors zur Beobachtung von kurzzeitigen Lichtphänomenen auf dem Mond
Dreiländertagung 2007 der SGPBF, DGPF und OVG, Muttenz / Basel, Schweiz, 19.-21. Juni 2007

Kayal H., Baumann, F., Briess, K., Montenegro, S.
BeeSat: A Pico Satellite for the On Orbit Verification of Micro Wheels
3rd International Conference on Recent Advances in Space Technologies, Istanbul, Turkey, 14-16 June 2007

Kayal H., Baumann, F., Briess, K.
Beesat – A Pico Satellite for the In-Orbit Verification of Miniaturised Wheels
6th IAA Symposium On Small Satellites for Earth Observation, Berlin, Germany, April 23 - 26, 2007

Kayal H., Briess, K., Ziegler B.
Satellite Constellation for Detection and Observation of the Transient Lunar Phenomenon
DGLR – International Symposium – “To Moon and beyond 2007” (14th – 16th March 2007, Hilton Hotel Bremen, Germany)

Baumann, F., Brieß, K., Kayal, H.
Untersuchung von Sensoren zur Lagebestimmung in Picosatellitenplattformen
Jahrestagung der Deutschen Gesellschaft für Photogrammetrie, Fernerkundung und Geoinformation e.V., 11-13 September, Berlin-Adlershof, 2006

Sarkarati, M., Briess, K., Kayal, H.
Design and Implementation of a Remote, Server- Client- Based Telemetry Retrieval and Monitoring System
AIAA-2006-5918, 9th International Conference on Space Operations, Rome, Italy, 19-23 June 2006

Montenegro, S., Briess, K., Kayal H.
Dependable and flexible Board Computer Software for Pico Satellites
DAta Systems In Aerospace, Hotel Palace Berlin, Germany, 22 – 25 May 2006

Trowitzsch, S., Baumann, F., Birke, H., Grewe, R., Kayal, H., Richter, D.
TUPEX An Experimental Sounding Rocket Payload for Evaluation of Pico Satellite Technologies
Space Technology Education Conference, Braunschweig, Germany, May 9th – 12th, 2006

Kayal, H., Brieß, K., Renner, U.
Small Satellites from Berlin
3rd Asian Space Conference, 21 – 23 March 2007, Singapore

Kayal, H., Brieß, K.
Pico and Nano Satellite Technologies at the Technical University of Berlin
IAC-05-B5.6.B.03, 56th International Astronautical Congress 2005, Fukuoka, Japan, October 2005

Kayal, H., Brieß, K.
Pico Satellite Concept of TU-Berlin
IAA-B5-1401, 5th IAA Symposium On Small Satellites for Earth Observation, Berlin, April 4 - 8, 2005

Baumann, F., Brieß, K., Kayal, H.
Drei-Achsen-stabilisierte Picosatellitenplattform für Fernerkundungsaufgaben
Jahrestagung der Deutschen Gesellschaft für Photogrammetrie, Fernerkundung und Geoinformation e.V., 21-23 September, Rostock, 2005

Sarkarati, M., Brieß, K., Kayal, H.
A Web-Based Modular and Flexible Data Acquisition and Telemetry Monitoring System for Micro Satellites
IAA-B5-1303, 5th IAA Symposium On Small Satellites for Earth Observation, Berlin, April 4 - 8, 2005

Kayal, H., Brieß, K., Eckler, J., Hillenmaier, O.
Miniaturisation - a New Evolution Level of Reaction Wheels
IAA-B5-1110P (Poster), 5th IAA Symposium On Small Satellites for Earth Observation, Berlin, April 4 - 8, 2005

Montenegro, S., Brieß, K., Kayal, H.
Dependable and Flexible Board Computer for Pico Satellites
IAA-B5-1101, 5th IAA Symposium On Small Satellites for Earth Observation, Berlin, April 4 - 8, 2005

Brieß, K., Kayal, H.
A Mission Analysis and Simulation System for Cost Effective Earth Observation Missions with Micro-, Nano- and Pico-Satellites
IAC-04-IAA-4.11.3.05, 55th International Astronautical Congress, 4-8 October 2004, Vancouver, B.C., Canada

Lorenz, E., Bärwald, W., Briess, K., Kayal, H., Schneller, M., Wüsten, H.
Résumés of the BIRD Mission
Proceedings of The 4S Symposium: Small Satellites, Systems and Services (ESA SP-571). 20 - 24 September 2004, La Rochelle, France. Editor: B. Warmbein. Published on CDROM., p.31.1

Halle, W., Briess, K., Kayal, H.
An autonomous information generation and distribution system for the next generation of small satellites: examples of the BIRD mission experiments
Proc. SPIE Vol. 5234, p. 572-579, Sensors, Systems, and Next-Generation Satellites VII; Roland Meynart, Steven P. Neeck, Haruhisa Shimoda, Joan B. Lurie, Michelle L. Aten; Eds., Feb 2004

Brieß, K., Bärwald, W., Gill, E., Kayal, H, Lorenz, E., Montenbruck, O., Montenegro, S., Halle, W., Schlicker, M., Skrbek, W., Studemund, H., Terzibaschian, T.
Technologiedemonstration mit dem DLR-Kleinsatelliten BIRD
Deutscher Luft- und Raumfahrtkongress 2002, Stuttgart, 23.-26. September 2002

Brieß, K., Montenegro, S., Bärwald, W., Halle, W., Kayal, H., Lorenz, E., Skrbek, W., Studemund, H., Terzibaschian, T., Walter, I.
Demonstration of small satellite technologies by the BIRD mission
16th Annual AIAA/USU Conference on Small Satellites, August 12 - 15, 2002

Kayal, H., Lauterbach, A.
Telemetry Reception and Commanding with a Low-Cost Ground Station for the Small Satellite BIRD
Proceedings, etc 2002, Garmisch-Partenkirchen, Germany, May 27 to 30, 2002, 174-184

Brieß, K., Bärwald, W. , Kayal, H., Lorenz, E., Oertel, D., Zhukov, B., Skrbek, W., Walter, I.
BIRD a Dedicated Mission for Remote Sensing of Vegetation Fires
29th ISRSE, Buenos Aires, Argentina, April 8 - 12, 2002

Gill, E., Montenbruck, O., Kayal, H., Brieß, K.
Combined space-ground autonomy for the BIRD small satellite mission
3rd IAA Symposium on Small Satellites for Earth Observation, April 2-6, 2001, Berlin, Germany

Gill, E., Brieß, K., Montenbruck, O., Kayal, H.
A concept for an autonomous space and ground segment applied to the BIRD satellite mission
Poster, 19th AIAA International Communications Satellite Systems Conference, Spring 2001

Kayal, H.
Development of an experimental low-cost ground station for the small satellite project BIRD
Space Ops 2000, 6th International Symposium, 19-23 June 2000, Toulouse, France

Kayal, H.
An Experimental Low-Cost Ground Station for the Small Satellite Project BIRD
in: H. P. Röser, Sandau, R., A. Valenzuela (Eds.): Small Satellites for Earth Observation, Digest of the 2nd. Int. Symp. of the IAA, Berlin, April 12-16, 1999, Wissenschaft u. Technik Verl., 143-146

Kayal, H.
A Low-Cost Ground Station for the Small Satellite BIRD
3rd International Symposium on Reducing the Cost of Spacecraft Ground Systems and Operations, March 22-24, 1999, NCKU, Institute of Aeronautics and Astronautics, Tainan, Taiwan

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