Space Research Centre Research Articles

LOFAR PL610 Station Data Product Specification

ABSTRACT Since 2017, the Space Research Centre of the Polish Academy of Sciences in Warsaw, Poland, has measured and gathered over 35,000 hours of observations with the use of the LOw Frequency ARray (LOFAR) radio telescope. This paper outlines the Standard Data Product acquired from the LOFAR PL610 station located in Borówiec, Poland. Within this context, we detail the data products that are accessible, provide metadata descriptions for them, and include an example of the data under both quiet and disturbed ionospheric conditions.

Laser Observations of GALILEO Satellites at the CBK PAN Astrogeodynamic Observatory in Borowiec

The laser station (BORL) owned by the Space Research Centre of the Polish Academy of Sciences and situated at the Astrogeodynamic Observatory in Borowiec near Poznań regularly observes more than 100 different objects in low Earth orbit (LEO) and medium Earth orbit (MEO). The BORL sensor’s laser observation range is from 400 km to 24,500 km. The laser measurements taken by the BORL sensor are utilized to create various products, including the geocentric positions and movements of ground stations, satellite orbits, the components of the Earth’s gravitational field and their changes over time, Earth’s orientation parameters (EOPs), and the validation of the precise Galileo orbits derived using microwave measurements, among others. These products are essential for supporting local and global geodetic and geophysics research related to time. They are crucial for the International Terrestrial Reference Frame (ITRF), which is managed by the International Earth Rotation and Reference Systems Service (IERS). In 2023, the BORL laser station expanded its list of tracked objects to include all satellites of the European satellite navigation system GALILEO, totaling 28 satellites. During that year, the BORL laser station recorded 77 successful passes of GALILEO satellites, covering a total of 21 objects. The measurements taken allowed for the registration of 7419 returns, resulting in 342 normal points. The average RMS for all successful GALILEO observations in 2023 was 13.5 mm.

Outcomes and Perspectives from the 4th ESA ModelBased Space Systems and Software Engineering Workshop (MBSE2023) on reducing the gap between model‐based systems engineering and domain‐specific approaches

AbstractIn the context of its initiative to promote the adoption of model‐based approaches in the development of present and upcoming missions, the European Space Agency (ESA) organised this year its annual workshop on Model‐Based Space Systems and Software Engineering (MBSE2023) at its European Space Research and Technology Centre (ESTEC) premises. The aim of this year's workshop was to investigate how the model‐based systems engineering community could contribute to bridging the gap with domain‐specific model‐based approaches used in subsystem design. The World Café Method was used to facilitate the group discussions, the outcomes of which are summarized and presented in this paper.

Space Debris Capture - About New Methods of Tethered Space Net Opening by Tubular Booms

Abstract Nowadays, space debris is one of the main subjects of discussion regarding satellites in Earth's orbit. Right now, there are about 26,000 orbiting satellites and only few of these satellites are operational. Recently, the Polish space sector has been strongly growing and delivering instruments working in space. The first part of this paper describes the several space instruments designed in the Space Research Centre Polish Academy of Science (SRC PAS). Instruments such as SWI, RPPWI, LPPWI, Ebox or Pre-boxes have been created for a mission to Jupiter named “JUICE”. After fulfilling their scientific mission, these instruments can increase the amount of debris in space. This is one of the reasons for taking up the topic of space debris reduction and the use of technical solutions used in this mission for the proposed solution presented later. The second part of this paper describes the new methods related to space debris. The activities can be related to the space debris removal programmes. The paper describes two methods developed by Polish scientists used for removal of space debris. One of them is the new capture method and mechanism designed for it. The special mechanism is based on tubular boom application for opening the net, to capture the space debris. The main parts of the mechanism are mechanisms which have been used in the JUICE space mission. The paper describes the main idea for these new methods, and for the design part prepared the strength confirmation by structural analysis. The main function of the mechanism has been verified by simulations and tests performed in laboratories.

An analysis of fog events in respect of winter season 2021-2022 using model reanalysis & INSAT-3D/3DR satellite data

The objective of the study was twofold (i) Review of INSAT-3D/3DR night time fog detection channel differencing (MIR- TIR1) scheme developed by Space Application Centre (SAC) Indian Space Research Centre (ISRO) thresholds which were not uniform for winter season radiation fog and vary geographically over Indian domain & (ii) An analysis of Fog events of 2021-2022 winter season analysis using the anomalies (temperature, wind, moisture, inversion, geo-potential height etc) from NCEP reanalysis and ERA-5 data sets. This study is a way forward to look into the importance of recently introduced model reanalysis data sets to monitor and understand the recent changes of fog events behaviour. It is seen that the fog events winter season (2021-2022) was reduced appreciably and this change is really a concern but 2021-22 winter fog occurrences were very well captured in both models as well as INSAT-3D/3DR data analysis. The results brought out from the model as well as satellite data analysis were found to be very useful for forecasters and end users especially in monitoring and prediction of fog events. However, to quantify the night time fog thresholds based on INSAT data for different regions of India and appreciable reduction of fog events in the recent past needs long term data sets study.

Investigation of long-term storage of space materials for future constellation missions: study of Braycote® 601 EF lubricant

The long-term storage (LTS) of space materials is becoming more and more critical for the next missions. For instance, for MTG (Meteosat Third Generation) mission, 5-year assemble, integration and testing (AIT) time on ground, up to 17.5-year storage for recurring models plus at least 8.5 years in orbit operation are planned. Hence, a good understanding of materials’ aging properties is desirable to ensure that materials’ specifications are still suitable after LTS, and, eventually, to anticipate the potential non-conformities. For this purpose, the European Space Research and Technology Centre (ESTEC) is investigating these problematics thanks to its wide capabilities from aging with environmental, climatic and vacuum chambers up to physico-chemical characterizations by numerous instruments such as microscopes, spectroscopes, thermal, mechanical or electrical analyzers. An overview is presented herein through the study of a fluorinated based grease lubricant named Braycote® 601EF widely used in mechanisms in space sector such as the US space shuttles actuator or the basic end effectors of The European Robotic Arm.

A Path to Research in Space Physics

AbstractSuccess in research depends on multiple factors, many outside the control of an individual. I was born during the Great Depression, began school during World War II, and was 12 years old before I lived in a house with running water, electricity, or a telephone. In the second or third grade, I decided to be a scientist, and all my activities after that contributed to this goal. In this paper, I summarize a few early events and focus on my activities in the Ph.D. Physics program at Berkeley, and my first few years after graduation. Being well‐prepared, hardworking, self‐sufficient, and blessed by fortunate circumstances is important. However, good fortune is insufficient if you are not proactive. Once success seems to be within grasp, it is important to consistently promote your ideas and communicate them in lectures and publications. Space Physics research exploded the year I started my research providing abundant opportunities for discoveries. There were few competitors, and significant resources were available. I was fortunate to be educated at one of the first space research centers and find a permanent position at another. Circumstances have changed in the 60 years since I began research. The opportunities for quick discoveries and rapid recognition have moved away from my field of magnetospheric physics. New instruments, new methods of analysis, large amounts of data, and advanced modeling tools are needed to make incremental advances.

The ESA Active Dosimeter (EAD) system onboard the International Space Station (ISS)

Ionizing radiation in general and mixed fields of space radiation in particular pose a risk of serious harm to human health. The risk of such adverse effects increases with the duration of the mission, and for all missions outside the protective properties of the Earth’s magnetic field and atmosphere. Accordingly, radiation protection is of central importance for all human spaceflight, which is recognized by all international space agencies. To date various systems, analyze and determine the exposure to ionizing radiation within the environment and to the crew onboard the International Space Station (ISS). In addition to this operational monitoring, experiments and technology demonstrations are carried out. This to further enhance systems capabilities, to prepare for exploratory missions, to the Deep Space Gateway and/or to enable for human presence at other celestial bodies. Subsequently the European Space Agency (ESA) decided early to support the development of an active personal dosimeter. Under the auspices of the European Space Research and Technology Center (ESTEC) together with the European Astronaut Center's (EAC) Medical Operations and Space Medicine (HRE-OM) team, a European industrial consortium was formed to develop, build, and test this system. To complete the ESA Active Dosimeter (EAD) Technology Demonstration in space, EAD components were delivered to ISS with the ESA’s space missions ‘iriss’ and ‘proxima’ in 2015 and 2016. This marked Phase 1 (2015) and 2 (2016–2017) of the EAD Technology Demonstration to which focus is given in this publication. All EAD systems and their functionalities, the different radiation detector, their properties, and calibrations procedures are described. Emphasis is first on the “iriss” mission of September 2015, that provided a complete set of data for an entire space mission from launch to landing, for the first time. Data obtained during Phase 2 in 2016–2017 are discussed thereafter. Measurements with the active radiation detectors of the EAD system provided data of the absorbed dose, dose equivalent, quality factor as well as the various dose contributions during the crossings of the South Atlantic Anomaly (SAA) and/or resulting from galactic cosmic radiation (GCR). Results of the in-flight cross-calibrations among the internal sensors of the EAD systems are discussed and alternative usage of the EAD Mobile Units as area monitors at various different locations inside the ISS is described.

A Complex Landscape of Fun, Queerness and Desire in China: Introducing Three Films by He Xiaopei

This article documents He Xiaopei’s work as a film activist who contributes significantly to feminist and queer movements in contemporary China. Trained as a social scientist, He Xiaopei then went on to become the director of the civil organization Pink Space Research Center in the mid-2000s as well as an independent filmmaker. Since 2010, she has produced more than ten documentary movies. However, despite the greatness of her contribution, the range of the topics she has covered, and her position in the feminist and queer movement in China, she has yet to receive the attention she deserves in English-speaking academia. This article selects three movies by He Xiaopei, i.e., The Lucky One, Playmates, and Bad Women of China, and provides an intersectional analysis of gender, friendship, migration, sexuality and intimate relationships, as seen through the lens of an ever-changing China on the global stage. At first glance, the three movies focus on different figures and themes, but they share the same core spirit – breaking through boundaries and limits, maintaining humour and positivity even when facing predicaments, embracing desire and depicting humanity as it manifests in complicated modern life.

Satellite-based crop identification and area estimation under the SATMIROL system

One important area where satellite-based Earth observation is applied in is agricultural statistics. The use of new digital technologies and satellite data have contributed to the modernisation of the aforementioned scientific area and is designed to overcome the problems that both agricultural statistics and the recipients of statistical data are faced with. The main aim of the article is to present an innovative system of satellite-based crop identification and crop growth monitoring – SATMIROL. The system was developed by Statistics Poland, the Institute of Geodesy and Cartography and the Space Research Centre of the Polish Academy of Sciences. SATMIROL provides agricultural statistics based on satellite data from the Copernicus programme and administrative data. The article focuses on selected modules of the system which involve the use of satellite remote sensing for crop identification. The study also presents a nationwide crop area estimation performed in three periods: 2019, 2020 and 2021. The implementation of SATMIROL allowed the presentation of statistical data on agriculture in spatial terms, which is not possible when applying traditional methods of data production. This new method of acquiring data enables their presentation at all levels of Poland’s administrative division, i.e. by voivodship, poviat (district) and gmina (commune).

Landform Geomorphology Classification of Ashkaft Fold

Land classification means unifying the shapes of the earth's surface and categorizing them into groups arranged according to a hierarchical hierarchical system that extends from the major terrestrial systems to the smaller terrestrial units Land forms are the result of a number of factors, the most important of which are (structural, climatic, hydrological and biological factors), as their effects are intertwined between the forces of resistance and the forces of movement in the formation of the land appearance, and by the energy they carry, they change the surface of the earth through its external processes (weathering and erosion forces) represented by physical variables. And the chemicals that play the main role in the evolution of the terrain, for example, weathering works to prepare the rocky crumbs for movement of different types: air and water, and the elements of climate have an effective role in activating geomorphic processes, as well as living organisms, humans, animals, and microorganisms. For this reason, the study of the landforms that resulted from the geomorphological factors and processes within the study area, through the analysis of topographic maps, and aerial photographs covering the study area according to what is available, in addition to documenting these forms in the field through the field study. The researcher relied on the global (ITC) system issued by the Space Research Center in the Netherlands, to classify the landforms, and according to what is in circulation, it is one of the best systems adopted in the departments (geographical and geological), which is based in its classification of landforms on the nature of geomorphological factors and processes Responsible for the formation of these forms, this is what is done and preferred by most geomorphologists in the world

Status of SSA activities in Poland and recent SST developments

The Polish activities in the SSA domain despite having been continuously developed from the beginning of the space era however have until recently mainly concentrated on the science and research domain. The Polish participation in various international SSA initiatives such as ESA SSA/Space Safety Programme, European Space Surveillance and Tracking Consortium (EUSST) represented by Polish Space Agency (POLSA) or Space Weather Service for ICAO PECASUS consortium represented by Space Research Centre of Polish Academy of Science has shifted those activities also into the operational domain. The current SSA system in Poland is based on the pool of the Polish scientific and commercial assets organized by the Polish space administration. Currently, Polish SST network consists of over 20 optical sensors operating for national purposes with a part contributing to EUSST. The paper presents a general outlook of SSA capability in Poland focusing mainly on the SST component, a preview of recent developments, and the preliminary results in terms of photometric solutions as an effort to extend current operational Polish capabilities in preparation for the future more complex environment in support of national and European efforts.

Development and Demonstration of Australian First Working Sodium Guide Star Laser

The Australian first working sodium guide star laser system has been designed and developed for various astronomical and space-related applications. A completely diode-pumped pulsed system was developed initially followed by a largely fiber-based continuous wave (CW) system operating at 589 nm achieved through a unique wavelength conversion scheme by combining 1342 and 1050 nm through a sum frequency generation process. For the CW system, single-mode laser beams at both 1342 and 1050 nm are achieved from fiber-based seed oscillators and fiber amplifiers. The output power of ~25 W at 1342 nm is achieved from a single frequency fiber Raman amplifier. Output power up to 70 W at 1050 nm is achieved from a Yb-doped fiber pre-amplifier followed by a Yb-doped fiber power amplifier. For the sum frequency generation process, optimum focusing parameters are evaluated and determined. The CW system has generated more than 20 W output power at 589 nm, a circularly polarised beam with a good beam quality, spectral linewidth ≤ 2 MHz, and the laser output locked on the sodium D2 line at 589.159 nm. The system has been successfully demonstrated at EOS Space Research Centre, Mt Stromlo, Canberra, and become the Australian first working sodium guide star laser system.

Measurements to Space Debris in 2016–2020 by Laser Sensor at Borowiec Poland

Abstract In 2014, a significant upgrade was made to the Borowiec (BORL 7811) laser-ranging system, which is the part of Space Research Centre of the Polish Academy of Sciences (SRC PAS). Two high-energy lasers modules were installed. First is the EKSPLA PL-2250, used for tracking objects equipped with retroreflectors. Second is the Continuum Surelite III, dedicated to the tracking of space debris without retroreflectors. In 2016, the BORL station joined the space debris tracking laser group and, since then, is tracking systematically inactive/defunct satellites and typical rocket bodies from LEO regime. Today, the BORL is tracking regularly about 80 different space debris objects. The paper presents the activity of the BORL laser station in observations of space debris. The results presented are from years 2016 to 2020. The sum of all passes from this period is almost 2 000, giving over 23 000 normal points. Average root mean square error (RMS) of objects with satellite laser ranging-dedicated (SLR-dedicated) retroreflectors ranges 1.5 cm–14 cm and of objects without SLR-dedicated retroreflectors ranges 8 cm–222 cm.

A novel device to study altered gravity and light interactions in seedling tropisms

Long-duration space missions will need to rely on the use of plants in bio-regenerative life support systems (BLSSs) because these systems can produce fresh food and oxygen, reduce carbon dioxide levels, recycle metabolic waste, and purify water. In this scenario, the need for new experiments on the effects of altered gravity conditions on plant biological processes is increasing, and significant efforts should be devoted to new ideas aimed at increasing the scientific output and lowering the experimental costs. Here, we report the design of an easy-to-produce and inexpensive device conceived to analyze the effect of interaction between gravity and light on root tropisms. Each unit consisted of a polystyrene multi-slot rack with light-emitting diodes (LEDs), capable of holding Petri dishes and assembled with a particular filter-paper folding. The device was successfully used for the ROOTROPS (for root tropisms) experiment performed in the Large Diameter Centrifuge (LDC) and Random Positioning Machine (RPM) at ESA's European Space Research and Technology centre (ESTEC). During the experiments, four light treatments and six gravity conditions were factorially combined to study their effects on root orientation of Brassica oleracea seedlings. Light treatments (red, blue, and white) and a dark condition were tested under four hypergravity levels (20 g, 15 g, 10 g, 5 g), a 1 g control, and a simulated microgravity (RPM) condition. Results of validation tests showed that after 24 h, the assembled system remained unaltered, no slipping or displacement of seedlings occurred at any hypergravity treatment or on the RPM, and seedlings exhibited robust growth. Overall, the device was effective and reliable in achieving scientific goals, suggesting that it can be used for ground-based research on phototropism-gravitropism interactions. Moreover, the concepts developed can be further expanded for use in future spaceflight experiments with plants.

A New Model of Quasigeoid for the Baltic Sea Area

The Space Research Centre in Warsaw is participating in the ESA project “Geodetic SAR for Height System Unification and Sea Level Research”. To observe the absolute sea level and enable the unification of the height systems, the physical heights of the tide gauge stations referring to a common equipotential surface (quasigeoid/geoid) are needed. This paper describes the new quasigeoid model for the area of the Baltic sea. The quasigeoid calculation was carried out according to the Helmert method, in which the topography is condensed on a layer lying on the geoid. Airborne gravity anomalies from the Baltic area and terrestrial anomalies from Sweden, Finland, Denmark, Lithuania, Latvia, and Poland were used. The necessary terrain corrections have been computed from a digital terrain model based on the SRTM30 model. To compute the long-wavelength part of the quasigeoid, the geopotential models GOCE-DIR6, GOCO06s, and EIGEN-6C4 were used; therefore, the three solutions have been obtained. All calculations were done in a zero-tide system. The new quasigeoid model is obtained on a regular 1.5’ × 3.0’ grid in the GRS80 reference system, covering the Baltic Sea and the surrounding area 52° < ϕ < 68° and 11° < λ < 30°. These gravimetric quasigeoids were compared to quasigeoid undulations derived at 29 GNSS/leveling points of the ASG-EUPOS permanent network, located in the study area. Our calculations show that the accuracy of the calculated quasigeoids is almost the same in all three cases and is about ±0.04 meters. Finally, quasigeoid anomalies were interpolated at the Polish tide gauge stations. The new gravimetric quasigeoid solution could be very important for height system unification, for geophysical purposes as well as for engineering purposes.

Hypergravity affects cell traction forces of fibroblasts

Cells sense and react on changes of the mechanical properties of their environment and, likewise, respond to external mechanical stress applied to them. However, whether the gravitational field as overall body force modulates cellular behavior is unclear. Different studies demonstrated that micro- and hypergravity influences the shape and elasticity of cells, initiate cytoskeleton reorganization, and influence cell motility. All these cellular properties are interconnected and contribute to forces that cells apply on their surrounding microenvironment. Yet, studies that investigated changes of cell traction forces under hypergravity conditions are scarce. Here, we performed hypergravity experiments on 3T3 fibroblast cells using the large-diameter centrifuge at the European Space Agency - European Space Research and Technology Centre. Cells were exposed to hypergravity of up to 19.5 g for 16 h in both the upright and the inverted orientation with respect to the g-force vector. We observed a decrease in cellular traction forces when the gravitational field was increased up to 5.4 g, followed by an increase of traction forces for higher gravity fields up to 19.5 g independent of the orientation of the gravity vector. We attribute the switch in cellular response to shear thinning at low g-forces, followed by significant rearrangement and enforcement of the cytoskeleton at high g-forces.

TRANSIENT MULTI-DOF VIBRATION TESTING: ANALYTICAL AND EXPERIMENTAL DATA

Abstract The HYDRA facility is a very large 6-Degrees-of-Freedom (DoF) hydraulic shaker located in the European Space Research and Technology Centre of ESA in The Netherlands. It has been recently used as test platform to perform a number of innovative, 6-DoF experimental vibration runs with the aim of assessing more flight-representative ways to dynamically qualify a spacecraft, hence reducing the level of conservatism. This paper focuses on the methodology behind the definition of the injected profiles computed by launcher/spacecraft coupled loads analysis, the performance achieved by HYDRA and its state-of-the-art MIMO control system, how the experimental data compare to the simulation ones, and aims also at defining success criteria for 6-DoF transient testing.

New data envelopment analysis models for classifying flexible measures: The role of non-Archimedean epsilon

Some input-output classifier data envelopment analysis (DEA) models in multiplier and envelopment forms were developed to designate the status of flexible measures, playing either input or output roles. These models ignore the role of non-Archimedean epsilon in the input-output classification process. We show that these epsilon-free models may ignore some flexible measures in the performance evaluation process and hence the status of such flexible measure(s) can be randomly and inappropriately identified. To fill this gap, we develop a pair of epsilon-based multiplier and envelopment classifier models. We also develop an approach to find a suitable epsilon value for our developed classifier models. A case study of the supplier selection problem in the Iranian Space Research Center (ISRC) is provided to illustrate the potential application of our new epsilon-based approach.

Hierarchical Control of Space Closed Ecosystems: Expanding Microgrid Concepts to Bioastronautics

One of the main challenges of human space exploration is the development of artificial ecosystems, which can be used as life support systems (LSSs) to enable long-duration human space missions. In an open LSS, no food generation or waste treatment is provided in space, and supplies from Earth are necessary. According to Figure 1, considering the approximate metabolic consumables and hygiene water as well as the number of crewmembers [1], a huge mass would be required to be transported from Earth, which brings the necessity of a regenerative or closed LSS [2]-[4]. Closed ecological systems (CESs) are ecosystems without any matter exchange with the outside environment [2]. The most advanced humanmade CESs include Advanced Life Support System Test Bed (ALSSTB) (the NASA Johnson Space Research Center, Houston, Texas), Biosphere 2 (Oracle, Arizona), BIOS-3 (Krasnoyarsk, Russia-no longer operative), the Closed Ecology Experiment Facility (CEEF) complex (Rokkasho, Japan), the Micro-Ecological Life Support System Alternative (MELiSSA) Pilot Plant (MPP) (Universitat Aut?noma de Barcelona, Spain), and the Concordia Antarctica Station, which are different from one another with respect to their complexity, size, and degree of closure [2]. CESs are necessary for long-term manned space missions, which aim to minimize support from Earth. They are composed of several specific compartments that, together, reproduce the main functionalities of an ecological system in a continuous mode of operation and under controlled conditions.