bluuebunny/crossref_metadata_2025 huggingface dataset:
Two new multirotor uncrewed aerial vehicles (UAVs) for glaciogenic cloud seeding and aerosol measurements within the CLOUDLAB project
Authors: Miller Anna J. , Ramelli Fabiola , Fuchs Christopher , Omanovic Nadja , Spirig Robert , Zhang Huiying , Lohmann Ulrike , Kanji Zamin A. , Henneberger Jan
Published: January 2024

Abstract. Uncrewed aerial vehicles (UAVs) have become widely used in a range of atmospheric science research applications. Because of their small size, flexible range of motion, adaptability, and low cost, multirotor UAVs are especially well-suited for probing the lower atmosphere. However, their use so far has been limited to conditions outside of clouds, first because of the difficulty of flying beyond visual line of sight and second because of the challenge of flying in icing conditions in supercooled clouds. Here, we present two UAVs for cloud microphysical research: one UAV (the measurement UAV) equipped with a Portable Optical Particle Spectrometer (POPS) and meteorological sensors to probe the aerosol and meteorological properties in the boundary layer and one UAV (the seeding UAV) equipped with seeding flares to produce a plume of particles that can nucleate ice in supercooled clouds. A propeller heating mechanism on both UAVs allows for operating in supercooled clouds with icing conditions. These UAVs are an integral part of the CLOUDLAB project in which glaciogenic cloud seeding of supercooled low stratus clouds is utilized for studying aerosol–cloud interactions and ice crystal formation and growth. In this paper, we first show validations of the POPS on board the measurement UAV, demonstrating that the rotor turbulence has a small effect on measured particle number concentrations. We then exemplify the applicability for profiling the planetary boundary layer, as well as for sampling and characterizing aerosol plumes, in this case, the seeding plume. We also present a new method for filtering out high-concentration data to ensure good data quality of POPS. We explain the different flight patterns that are possible for both UAVs, namely horizontal or vertical leg patterns or hovering, with an extensive and flexible parameter space for designing the flight patterns according to our scientific goals. Finally, we show two examples of seeding experiments: first characterizing an out-of-cloud seeding plume with the measurement UAV flying horizontal transects through the plume and, second, characterizing an in-cloud seeding plume with downstream measurements from a POPS and a holographic imager mounted on a tethered balloon. Particle number concentrations and particle number size distributions of the seeding plume from the experiments reveal that we can successfully produce and measure the seeding plume, both in-cloud (with accompanying elevated ice crystal number concentrations) and out-of-cloud. The methods presented here will be useful for probing the lower atmosphere, for characterizing aerosol plumes, and for deepening our cloud microphysical understanding through cloud seeding experiments, all of which have the potential to benefit the atmospheric science community.
Nine years of warming and nitrogen addition in the Tibetan grassland promoted loss of soil organic carbon but did not alter the bulk change in chemical structure
Authors: Sun Huimin , Schmidt Michael W. I. , Li Jintao , Li Jinquan , Liu Xiang , Ofiti Nicholas O. E. , Zhou Shurong , Nie Ming
Published: January 2024

Abstract. Nitrogen (N) and warming effects on ecosystem carbon (C) budgets and stabilization are critical to understand as C sequestration is considered as a mechanism to offset anthropogenic CO2 emissions, which is important for accurately predicting ecosystem C sequestration and/or potential C loss, remaining controversial though. However, the relevant information, especially for the intervention of environmental controls on grassland soil, is limited in Tibetan Plateau (TP) regions. Here we used a 9-year two-way factorial experiment involving warming with open top chambers (+1.80 ∘C in the daytime and +0.77 ∘C in the nighttime at the soil surface) and multilevel nitrogen (N) enrichment treatments (0, 5, 10, and 15 gm-2yr-1) in the TP to investigate the changes in soil organic carbon (SOC) pool size and chemical structure. Nine-year warming treatment significantly decreased SOC stock in the Tibetan grassland. We observed decreasing SOC concentrations which may be related to changes in the C-degrading enzymes. Surprisingly, the SOC molecular structure remained unchanged in all N-enrichment and warmed plots, suggesting that both treatments had affected all forms of SOC, from simple and complex polymeric in a similar way. Our results suggest that long-term warming stimulates soil C loss but no preference in SOC loss with different chemical structures.
Continental scientific drilling and microbiology: (extremely) low biomass in bedrock of central Sweden
Authors: Westmeijer George , Escudero Cristina , Bergin Claudia , Turner Stephanie , Ståhle Magnus , Mehrshad Maliheh , Leroy Prune , Buck Moritz , López-Hernández Pilar , Kallmeyer Jens , Amils Ricardo , Bertilsson Stefan , Dopson Mark
Published: January 2024

Abstract. Scientific drilling expeditions offer a unique opportunity to characterize microbial communities in the subsurface that have long been isolated from the surface. With subsurface microbial biomass being low in general, biological contamination from the drilling fluid, sample processing, or molecular work is a major concern. To address this, characterization of the contaminant populations in the drilling fluid and negative extraction controls are essential for assessing and evaluating such sequencing data. Here, rock cores down to 2250 m depth, groundwater-bearing fractures, and the drilling fluid were sampled for DNA to characterize the microbial communities using a broad genomic approach. However, even after removing potential contaminant populations present in the drilling fluid, notorious contaminants were abundant and mainly affiliated with the bacterial order Burkholderiales. These contaminant microorganisms likely originated from the reagents used for isolating DNA despite stringent quality standards during the molecular work. The detection of strictly anaerobic sulfate reducers such as Candidatus Desulforudis audaxviator suggested the presence of autochthonous deep biosphere taxa in the sequenced libraries, yet these clades represented only a minor fraction of the sequence counts (< 0.1 %), hindering further ecological interpretations. The described methods and findings emphasize the importance of sequencing extraction controls and can support experimental design for future microbiological studies in conjunction with continental drilling operations.
Investigating the role of stratospheric ozone as a driver of inter-model spread in CO2 effective radiative forcing
Authors: Byrom Rachael , Myhre Gunnar , Olivié Dirk , Schulz Michael
Published: January 2024

Abstract. Addressing the cause of inter-model spread in carbon dioxide (CO2) radiative forcing is essential for reducing uncertainty in estimates of climate sensitivity. Recent studies demonstrate that a large proportion of this spread arises from variance in model base state climatology, particularly the specification of stratospheric temperature, which itself plays a dominant role in determining the magnitude of CO2 forcing. Here we investigate stratospheric ozone (O3) as a cause of inter-model differences in stratospheric temperature, and hence its role as a contributing factor to spread in CO2 radiative forcing. We use the Norwegian Earth System Model 2 (NorESM2) to analyse the impact of systematic increases/decreases in stratospheric O3 on the magnitude of 4xCO2 effective radiative forcing (ERF) and its components. Firstly, we demonstrate that accurate estimation of instantaneous radiative forcing requires the use of host-model radiative transfer calculations. Secondly, we show that a 50 % increase and decrease in stratospheric O3 concentration leads to significant differences in base state stratospheric temperature, ranging from +6 K to -9 K, respectively. However, this does not result in a correspondingly large spread in CO2 ERF due to the impact of base-state stratospheric temperature on the emission of outgoing longwave radiation and the spectral overlap of CO2 and O3. We conclude that inter-model differences in stratospheric O3 concentration are therefore not predominantly responsible for inter-model spread in CO2 ERF.
Phosphorus supply and floodplain design govern phosphorus reduction capacity in remediated agricultural streams
Authors: Hallberg Lukas , Djodjic Faruk , Bieroza Magdalena
Published: January 2024

Abstract. Agricultural headwater streams are important pathways for diffuse sediment and nutrient losses, requiring mitigation strategies beyond in-field measures to intercept the transport of pollutants to downstream freshwater resources. As such, floodplains can be constructed along existing agricultural streams and ditches to improve fluvial stability and promote deposition of sediments and particulate phosphorus. In this study, we evaluated 10 remediated agricultural streams in Sweden for their capacity to reduce sediment and particulate phosphorus export and investigated the interplay between fluvial processes and phosphorus dynamics. Remediated streams with different floodplain designs (either on one side or both sides of the channel, with different width and elevation) were paired with upstream trapezoidal channels as controls. We used sedimentation plates to determine seasonal patterns in sediment deposition on channel beds and floodplains and monthly water quality monitoring. This was combined with continuous flow discharge measurements to examine suspended sediment and particulate phosphorus dynamics and reduction along reaches. Remediated streams with floodplains on both sides of the channel reduced particulate phosphorus concentrations and loads (−54 µg L−1, −0.21 kg ha−1 yr−1) along reaches, whereas increases occurred along streams with one-sided floodplains (27 µg L−1, 0.09 kg ha−1 yr−1) and control streams (46.6 µg L−1). Sediment deposition in remediated streams was five times higher on channel beds than on floodplains and there was no evident lateral distribution of sediments from channel to floodplains. There was no effect from sediment deposition on particulate phosphorus reduction, suggesting that bank stabilization was the key determinant for phosphorus mitigation in remediated streams, which can be realized with two-sided but not one-sided floodplains. Further, the overall narrow floodplain widths likely restricted reach-scale sediment deposition and its impact on P reductions. To fully understand remediated streams' potential for reductions in both nitrogen and different phosphorus species and to avoid pollution swapping effects, there is a need to further investigate how floodplain design can be optimized to achieve a holistic solution towards improved stream water quality.
Laser-tracker-based reference measurement for geometric calibration of phase-measuring deflectometry with active display registration
Authors: Sperling Yann , Bergmann Ralf Bernhard
Published: January 2024

Abstract. Phase-measuring deflectometry (PMD) with active display registration (ADR) is a ray-optics-based technique for the shape measurement of specular surfaces. To obtain quantitative results, the relative position of the cameras of the PMD–ADR setup needs to be determined by geometric calibration. Geometric calibration can be performed by inserting a planar mirror into the setup that brings all camera fields of view to overlap on an active pattern display. The mirror is tilted to multiple positions and each time the cameras capture the displayed images, which yields sufficient data to obtain the relative camera positions and the positions of the mirror. In this article, we give a more detailed description of PMD–ADR and its calibration. We also implement a laser-tracker-based reference method to measure the mirror positions and use its result to expose systematic errors in the geometric calibration.
Impact-based flood forecasting in the Greater Horn of Africa
Authors: Alfieri Lorenzo , Libertino Andrea , Campo Lorenzo , Dottori Francesco , Gabellani Simone , Ghizzoni Tatiana , Masoero Alessandro , Rossi Lauro , Rudari Roberto , Testa Nicola , Trasforini Eva , Amdihun Ahmed , Ouma Jully , Rossi Luca , Tramblay Yves , Wu Huan , Massabò Marco
Published: January 2024

Abstract. Every year Africa is hit by extreme floods which, combined with high levels of vulnerability and increasing population exposure, often result in humanitarian crises and population displacement. Impact-based forecasting and early warning for natural hazards is recognized as a step forward in disaster risk reduction, thanks to its focus on people, livelihoods, and assets at risk. Yet, the majority of the African population is not covered by any sort of early warning system. This article describes the setup and the methodological approach of Flood-PROOFS East Africa, an impact-based riverine flood forecasting and early warning system for the Greater Horn of Africa (GHA), with a forecast range of 5 d. The system is based on a modeling cascade relying on distributed hydrological simulations forced by ensemble weather forecasts, link to inundation maps for specific return period, and application of a risk assessment framework to estimate population and assets exposed to upcoming floods. The system is operational and supports the African Union Commission and the Disaster Operation Center of the Intergovernmental Authority on Development (IGAD) in the daily monitoring and early warning from hydro-meteorological disasters in eastern Africa. Results show a first evaluation of the hydrological reanalysis at 78 river gauging stations and a semi-quantitative assessment of the impact forecasts for the catastrophic floods in Sudan and in the Nile River basin in summer 2020. More extensive quantitative evaluation of the system performance is envisaged to provide its users with information on the model reliability in forecasting extreme events and their impacts.
The evolution of Arctic permafrost over the last 3 centuries from ensemble simulations with the CryoGridLite permafrost model
Authors: Langer Moritz , Nitzbon Jan , Groenke Brian , Assmann Lisa-Marie , Schneider von Deimling Thomas , Stuenzi Simone Maria , Westermann Sebastian
Published: January 2024

Abstract. Understanding the future evolution of permafrost requires a better understanding of its climatological past. This requires permafrost models to efficiently simulate the thermal dynamics of permafrost over the past centuries to millennia, taking into account highly uncertain soil and snow properties. In this study, we present a computationally efficient numerical permafrost model which satisfactorily reproduces the current ground temperatures and active layer thicknesses of permafrost in the Arctic and their trends over recent centuries. The performed simulations provide insights into the evolution of permafrost since the 18th century and show that permafrost on the North American continent is subject to early degradation, while permafrost on the Eurasian continent is relatively stable over the investigated 300-year period. Permafrost warming since industrialization has occurred primarily in three “hotspot” regions in northeastern Canada, northern Alaska, and, to a lesser extent, western Siberia. We find that the extent of areas with a high probability (p3 m>0.9) of near-surface permafrost (i.e., 3 m of permafrost within the upper 10 m of the subsurface) has declined substantially since the early 19th century, with loss accelerating during the last 50 years. Our simulations further indicate that short-term climate cooling due to large volcanic eruptions in the Northern Hemisphere in some cases favors permafrost aggradation within the uppermost 10 m of the ground, but the effect only lasts for a relatively short period of a few decades. Despite some limitations, e.g., with respect to the representation of vegetation, the presented model shows great potential for further investigation of the climatological past of permafrost, especially in conjunction with paleoclimate modeling.
Surface all the way through
Authors: Richardson Arianna
Published: January 2024

Images and details from a studio-based sculptural practice from a Canadian artist who works only with plastic.
TARGETED IMMUNOTHERAPY FOR HEPATOCELLULAR CARCINOMA: A CLINICAL CASE
Authors: Kashakov B. , Akbarova M.
Published: January 2024

Relevance: Hepatocellular carcinoma (HCC) is the most common malignant tumor of the liver. HCC is one of the most important problems of the oncology service of Kazakhstan, as it has a progressive course, late detection, low survival, and unfavorable prognosis.

The study aimed to evaluate the use of targeted immunotherapy in treating hepatocellular carcinoma in a clinical example.

Methods: The paper presents a clinical case of targeted immunotherapy in combination with Atezolizumab 1200 mg + Bevacizumab 800 mg, once every 3 weeks, in treating HCC in the Regional Oncology Center in Kyzylorda.

Results: The first symptoms of liver damage appeared in 2018, at which time HCC was discovered. Viral hepatitis B was diagnosed in 2016. MRI OBP from 15.08.20: a picture of the right lobe of the liver in S5 – 9×7×6 cm, in S3 – 3.7 cm, in S7 – 3.0 cm, in S8 – 2.5 cm. During the follow-up examination (July 2021), the enzyme immunoassay revealed a high angiotensin-converting enzyme (ACE) level of 450.56 IU/ml; the abdominal CT scan showed no deterioration. Later, despite the therapy, ACE increased rapidly: 2,595.3 IU/ml (August 2021) and 2,142.25 IU/ml (September 2021), and the therapy was changed to Regorafenib. ACE continued to rise to 4,405 IU/ml (November 2021) and 18,005 IU/ml (December 2021). A control abdominal CT scan showed a moderate reduction in the size of the tumor.

Taking into account a steady ACE increase, in February 2022, the patient was recommended therapy with Atezolizumab and Bevacizumab. In January 2023, the patient has already received 13 courses, and ACE continued to decrease: 1,932 IU/ml (January 2023), 53.38 IU/ml (February 2023), 16.07 IU/ml (March 2023), and the abdominal CT scan showed positive dynamics.

Conclusion: Targeted immunotherapy showed its effectiveness in the described case of inoperable HCC and allowed the patient to continue living, working, and leading an active lifestyle for more than 18 months.
Design of the MMX Rover Attitude Control System for Autonomous Power Supply
Authors:   Centre National d’Etudes Spatiales (CNES), Toulouse, France, Lagabarre Sandra , Goulet Sébastien , Tardivel Simon , IJpelaan Frans , Buse Fabian , Barthelmes Stefan , Skibbe Juliane
Published: January 2024

The Martian Moons eXploration (MMX) mission led by the Japan Aerospace Exploration Agency (JAXA) aims at studying Phobos and Deimos, with a launch planned mid-2024. It includes a small rover (about 30kg) carried out jointly by the French Space Agency (CNES, Centre National des Etudes Spatiales) and the German Aerospace Center (DLR, Deutsches Zentrum für Luft- und Raumfahrt), released from the main spacecraft to explore the surface of Phobos.

The MMX rover survival depends on its ability to charge its battery, powered by a solar array (SA) fixed with respect to the rover body. For that purpose, the attitude control system‎ (SKA, System für die Kontrolle of the Attitude) manages the orientation of the rover, using the locomotion system‎ (its "legs") and based on a sun sensor measurements. Conceptually, the system stems from a classic Attitude Determination and Control System‎‎ (ADCS), but the specifics are due to the dynamic interaction between the wheels and the regolith: mouvements limitation to avoid sinkage, delays in the control loop.

This paper presents the SKA architecture, through the various challenges encountered: limited design flexibility with major changes during the development, small knowledge of Phobos' expected soil, "nanosatellite philosophy" constraints and in particular very tight schedule to meet the JAXA delivery date (mid-2023). The design drivers were to create the most simple, robust and efficient system to orient the rover in order to maximize the battery charge, while ensuring the rover stability and addressing all of the above issues. A particular focus is made on the preliminary simulation results. Finally, the way forward is outlined with the development and validation steps.
AOCS FINE POINTING TECHNIQUES FOR ESA PLATO MISSION
Authors:   Thales Alenia Space France, Cannes, France, Kutrowski Nicolas , Cruciani Pietro
Published: January 2024

Planned for a launch in December 2026, PLATO is the 3rd medium mission of the Cosmic Vision ESA program.

Based on a payload consisting of 26 cameras that will look at transit of exoplanets in front of their stars, the pointing requirements of PLATO are very stringent.

In order to fulfill the required pointing performances, the AOCS is relying on the use of a Fine Guidance System (FGS), which is part of the payload and on different fine pointing techniques, some of which were developed by Thales Alenia Space in the frame of PLATO.

In the first part, the presentation will recall the objectives and constraints of the PLATO mission, while presenting the AOCS main pointing requirements (APE, MPE, PDE, RPE, performance in frequency domain) and the design of this “payload in the loop” AOCS.

In the second part, the different fine pointing techniques will be presented. A focus will be done on the different Kalman filters used for the attitude and angular rates estimation, reaction wheels friction torque estimation, and also how the AOCS is compensating for misalignment between attitude sensors (FGS and Star trackers) and the effect of the kinematic aberration of stars on the FGS line of sight.
Propellant sloshing effect modelling of spacecraft with Machine Learning
Authors:   Airbus Defence And Space, Toulouse, France, Denis Jules-Edouard , Ortiz Casanova Oscar , Manuel Juanpere Xavier , Coustie Oihana , Thevenot Claire , Evain Hélène , Standarovski Denis
Published: January 2024

The sloshing effect of liquids occurring within spacecraft’s fuel tanks is a determinant factor in the pointing performance of space missions with high-reactivity needs. Accurately modelling this phenomenon allows anticipating its detrimental effects on satellite control, and thus possibly improve the tranquillisation time.

This paper examines a modelling trade-off between the quick but low performance analytical approaches and the slow but accurate CFD simulations. Based on the hypothesis that the problem presents underlying regularity characteristics, and considering that dataset can be generated thanks to CFD simulations, Machine Learning techniques are explored, from a Proof of Concept approach to a fully representative agile space mission.

Using Machine Learning techniques such as Multi-Layer Perceptron (MLP), Long-Short Term Memory (LSTM) or Convolutional Neural Network (CNN), this study demonstrates high-accuracy results whilst remaining efficient in terms of computation time. Furthermore, its industrialization capability for future missions is assessed, providing promising results. For instance, it is shown that a relatively small dataset is needed to reach high representativeness and robustness. Besides, a methodology is developed to implement these models into a Guidance, Navigation and Control (GNC) closed loop simulator based on Matlab/Simulink.
High-Accuracy Star Tracker ASTRO XP
Authors:   Chief Engineer Star Sensors, Jena, Germany, Schmidt Uwe , Würl Richard , Griebel Martin , Reichardt Jörg , Adolf Daniel , Kühn Thomas , Kirschstein Steffen , Steinbach Ingolf
Published: January 2024

Jena-Optronik GmbH, located in Jena/Germany, has profound experience in designing and

manufacturing star trackers since the early 80ties. Today, the company has a worldwide leading

position in supplying satellites and other spacecraft for telecom, earth observation, science and all

kind of missions in various orbits with versatile and reliable star tracker systems. The future ESA

science missions require high accuracy star trackers in the 0.1arcsec accuracy class to achieve

the envisaged pointing budgets. Jena-Optronik received a pre-development contract (ESA

Contract No. 4000112514/14/NL/BW) from the European Space Agency in order to demonstrate

the feasibility of such a high accuracy star tracker within the challenging performance, mass and

envelope requirements. The here identified key-enabling optics technology in terms of a compact

4-times folded fully reflective optical system opened the way forward to a second contract (ESA

Contract No. 4000126831/19/NL/GLC/hh) to establish an engineering model optical head in form,

fit and function, able to undergo pre-qualification tests.

The star tracker optics consists of a full catoptric design and is therefore free of any chromatic

aberration. This is essential for a high accuracy star tracker, which uses guide stars from a wide

range of different spectral classes. The only four optics main parts are made from fused silica and

build in the final assembly a self-sustaining optical system with a total lack of CTE mismatches.

The high performance imaging system is completed with a FaintStar2 CMOS APS based focal

plane. The FaintStar2 is the most advanced and space-qualified APS star tracker imager as a

result of the ESA detector development roadmap. This detector comprises a complete system-on-

chip including a space-wire interface. This minimizes the power consumption of the ASTRO XP

optical head ensuring an excellent thermal-mechanical stability.

The ASTRO XP EM optical head was integrated in Q4/2022 so that the test readiness review with

the agency could be successfully performed. The paper presents insights in the optics and focal

plane technology and design. In addition, the first test results from the engineering model test

campaign will be published and discussed. The ASTRO XP optical head manufactured is the most

innovative star tracker ever designed at Jena-Optronik GmbH and beyond. This design applies

novel technologies and utilizes the most innovative high-technology assembly processes.
Determining Dimorphos' mass from the wobble of Didymos
Authors:   Aurora Technology B.V. for the European Space Agency (ESA), Villanueva de la Cañada, Spain, Grieger Björn , Küppers Michael
Published: January 2024

In order to demonstrate of the feasibility of the deflection of an Earth threatening asteroid, the DART mission impacted Dimorphos, the asteroid moonlet of Didymos, on 26 September 2022. For the assessment of the efficiency of the momentum transfer, the mass of Dimorphos needs to be known.

Around October 2026, the Hera mission will reach the Didymos binary system and inspect closely its properties and the consequences of the DART impact. The mass of Dimorphos is so small that it will only marginally be possible to measure its gravitational impact by tracking of the spacecraft trajectory. However, images taken by the Asteroid Framing Cameras aboard Hera will make it possible to measure the wobble of Didymos introduced by its common orbiting with Dimorphos around the barycenter of the binary system. This will enable the estimation of Dimorphos' mass.

In 2016, we discussed the expected accuracy of such a mass reconstruction under different assumptions (EGU2016-12296). So far, we had skiped the process of actually defining landmarks and measuring their pixel positions in images. From the Rosetta mission we know that this can be done with about one pixel accuracy. We just assume landmark positions in the body fixed frame randomly distributed over the surface of Didymos. The available measurements are then inertially referenced directions from the spacecraft to the landmarks at different times (images).

In the reconstruction process, we assume that we do not know anything about the true landmark positions, the spacecraft trajectory, and the orientation of Didymos. Image by image, we estimate the pose (position and attitude) of the asteroid relative to the spacecraft. Through many iterations over all images, the landmark positions in the body fixed frame are optimized. Because the attitude of the spacecraft is known, this provides the trajectory of the spacecraft relative to Didymos. The trajectory reconstructed in this way is falsified in the sense that it comprises the wobble of Didymos around its common barycenter with Dimorphos.

In a second step, we filter the wobble out of the spacecraft trajectory and estimate its size. Here, we assume that the orbit of Dimorphos is known, so we know the period of the wobble and its direction at all times.

So far, each time point had been treated separately. With the additional assumption of a continuous asteroid rotation and its appropriate modeling, the accuracy of the mass estimation can be improved. Moreover, with the new data from the DART mission and the matured design of the Hera mission, we are now able to refine the predictions and prepare in more detail the strategy for the reconstruction of the mass of Dimorphos.
INTEGRAL operations and mission rescue without thrusters
Authors:   Airbus Defence and Space Ltd., Stevenage, United Kingdom, Chapman Patrick , Southworth Richard , Martin Jim
Published: January 2024

The INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) is an operational European space observatory mission. It was launched in 2002, and has exceeded its original mission duration by a long margin, and has had several mission extensions approved.

In recent years several events have created interesting challenges for attitude control. In 2020 the fuel unexpectedly depleted earlier than predicted, making normal thruster-based angular momentum off-loading impossible. It was possible to devise a workaround for this, managing momentum using solar torque and "Z-flip" slews. The slew algorithm was redesigned by ESOC and industry to remove a previous constraint that can require momentum off-loading.

In Sep. 2021 a major anomaly put the spacecraft into an uncontrolled tumbling state for several hours. This paper describes the successful improvised recovery of attitude control using reaction wheels, and the subsequent development of procedures and a completely new AOCS mode, a wheel-based New Safe Mode (NSM) to prevent a recurrence of loss of control. With NSM, the mission will have the ability to be safely operated without thrusters and with redundancy for any further unit failures until predicted re-entry in 2029.
Assisted Reentry for All-Electric LEO Spacecraft
Authors:   Airbus Defence And Space, Toulouse, France, Lagadec Kristen , Gegout Dorian
Published: January 2024

There have historically been only two strategies to choose from when designing a deorbiting capability for future LEO missions: controlled reentry requires a very large deorbit boost and thus a powerful propulsion system, while uncontrolled reentry is only allowed for small satellites that (almost) entirely burn up when reentering.

Assisted Natural Reentry (or assisted reentry for short) intends to fill the continuum between these two extremes, thus offering more design flexibility to comply with the 1/10,000 rule in terms of ground risk.

The main rationale is that if the orbital plane can be phased correctly with the Earth and the distribution of potential reentry locations can be confined to at most a couple of revolutions, the vast majority of reentries will occur above oceans, reducing the casualty risk by an order of magnitude with respect to uncontrolled reentry.

We present the design and performances of an assisted reentry strategy tailored for an all-electrical LEO satellite, i.e. one with a very low thrust/mass ratio which only allows quasi-static perigee lowering and offers minimal control authority. We demonstrate with extensive simulation campaigns that despite high uncertainty in aerodynamic and atmospheric models and large density swings due to unpredicted changes in solar activity, the final dispersion can be kept within 2 orbits of the nominal reentry location, reducing casualty risk by a factor >5.
On-Board Deployment Event Verification for GOES-R Spacecraft
Authors:   Lockheed Martin, Littleton, United States, Chapel Jim , Bevacqua Tim , Ramsey Graeme , Gehling Russell , Rood Timothy , Freesland Douglas , Krimchansky Alexander
Published: January 2024

As is common with many spacecraft designs, the GOES-R vehicles require a series of deployment events to transition from the launch configuration to the operational configuration. Rather than implementing additional sensors to verify various deployments, the GOES-R program developed an alternate approach that uses existing gyro rate sensing. The approach includes two pieces: the first is a new onboard shock detection capability to confirm initiation of individual deployment events, and the second is a ground-based dynamics verification step to confirm completion of deployment events. We first present the algorithm that detects shock events for various deployment devices along with the parameter tuning performed during ground tests. We then show inflight performance of the shock detection algorithm. While shock detection is useful for observing initiation of deployment events, completion of some deployment events cannot be determined by shock detection alone. For these events, such as solar panel latch-up and deployable boom extension, the program developed dynamics models for the deployment transient responses. High-rate gyro data were recorded for these events, which allow the ground team to verify that the appendages were fully deployed. We show the predictive models for these events and corresponding flight results.
AQUILA and 3AA: design and test results of high-accuracy accelerometer sensor and equipment
Authors:   Innalabs Ltd, Blanchardstown, Ireland, Torasso Alberto , Francis Rabin , Vandersteen Jeroen
Published: January 2024

InnaLabs Ltd, a privately held limited company incorporated in Ireland in 2011, is producing European ITAR-free Quartz Pendulous accelerometers since 2013, achieving top-end navigation performance with its AI-Q-2000 series of accelerometers. Thousands of those accelerometers have been since integrated into a wide range of land, marine, and aerospace platforms. These accelerometers have recently been successfully used in rocket launchers to support inertial navigation, demonstrating compatibility of the technology with space applications.

AQUILA is a very high performance rad-hard accelerometer based on Innalabs quartz-pendulum accelerometer technology. It uses the same pendulum subassembly as the AI-Q-2000 family, but electronics have been developed to meet space PA/QA standards. A hybrid electronics component populated with thoroughly-selected high-reliability EEE parts has been designed for that purpose. Furthermore, performance is specified to meet the most demanding space navigation applications, in particular with the objective of supporting delta-v manoeuvres measurement.

AQUILA was developed with the primary goal of qualifying an alternative to non-EU Navigation Grade Space accelerometers currently used on board ESA missions and other European Primes’ platforms (with similar fit, form and function). Performance specifications include, among others, very low noise, stringent bias and scale factor stability (i.e. 0.1µg short term stability, 2µg over 1 hour, 50µg over 1 month, and scale factor stability over 1 month of 100ppm) under full operating conditions (i.e. temperature, time, launch environment), including more than 15-years exposure to Space radiations (100krad goal). AQUILA is re-using the electro-mechanical cell used in the InnaLabs AI-Q-2000 series of COTS accelerometers which are proven insensitive to radiations and robust to stringent mechanical shock and vibration levels.

3 Axis Accelerometer (3AA) is a new equipment designed to provide acceleration and delta-v measurement on boards satellites and space systems. It includes 3 AQUILA accelerometers mounted in orthonormal orientation to provide measurement along 3 axes. 3AA is equipped with a standard 28V power interface and UART communication bus to easily interface with the main on board computer. The equipment allows for accelerometer compensation and calibration in flight (temperature, misalignment, etc.), providing the main on board computer with a high precision acceleration and delta-v measurement.

This paper describes the specification and design of AQUILA Dry Pendulous Servo accelerometer and of the 3 Axis Accelerometer. The paper will also present testing results from AQUILA development models built so far, showing that the product meets the specified performance. Schedule of the development till completion of the qualification will be presented.
The CIMR satellite– challenges and design solutions for AOCS system
Authors:   Esa, Noordwijk, Netherlands, Santilli Francesco , Hyslop Andrew , Triggianese Mariel , Sallusti Marcello , Santoni F. , Primavera A. , Zaccari G. , Gennari F. , Colella A. , Ficorilli M. , Kornienko Andrey
Published: January 2024

The Copernicus Imaging Microwave Radiometer (CIMR) is a European Earth Observation mission consisting of 2 satellites (with an option of the extension to the third one). It will provide high resolution global monitoring of the Earth surface emissions across various frequency bands, in particular floating sea ice parameters. The 3-axis stabilized spacecraft(s) will operate in a sun synchronous orbit with 817 km altitude. The instrument features a deployable mesh reflector with the diameter of 8 meters and its feed cluster, which rotates at 8 rpm to produce a 1900km wide ground swath.

The CIMR mission is currently in the C/D development phase and is being developed by a European space consortium with Thales-Alenia-Space Rome as a prime contractor.

The unique configuration consisting of the 3-axis stabilized platform and a spinning instrument poses various technical challenges for the AOCS design. The design drivers have been identified as follows:

•Provision of onboard angular momentum management to accommodate for large rotating instrument.

•Sophisticated spacecraft dynamic phenomena caused by

a)flexibility of the deployable rotating antenna

b)static and dynamic unbalance of the rotating instrument

c)fuel sloshing

•Capability to perform collision avoidance maneuvers throughout nominal operation and controlled reentry at the end of mission lifetime

•Managing the onboard Fault Detection, Isolation and Recovery (FDIR) with the objective of maximizing the scientific operation.

This paper gives an overview of the CIMR AOCS design, in particular

•Description of the avionics hardware setup

•Basic AOCS modes and transitions

•FDIR concept description

Besides the general overview few critical design solutions developed for CIMR will be presented in more detail:

•Static and dynamic unbalance on-board estimation using gyro rate measurements and compensation through active balancing system

•Preliminary design of onboard control laws that meet the performance requirements and guarantee the overall systems stability and robustness in presence of undesired coupling caused by internal disturbances, flexible dynamics, and time-varying uncertainties.

•Controlled reentry manoeuvre through multiple apogee thruster firings in presence of critical drag at perigee passages.
Study of re-entry guidance for orbital recovery and rocket first stage recovery
Authors:   Jaxa, Tsukuba, Japan, Matsumoto Shuichi , Arai Hisaaki , Sakai Tomohiko
Published: January 2024

For new space transport missions such as orbital recovery from Low Earth Orbit (LEO) and the rocket first stage recovery, accurate reentry guidance has become increasingly important. JAXA realized two orbital recovery missions, Orbital Reentry Experiment (OREX) and HTV Small Re-entry Capsule (HSRC). The recovery accuracy of OREX is about 100km and those of HSRC is about 10km. However practical capsule recovery system will need about 1km accuracy to land on Japan mainland. In this paper shows the way to realize 1km reentry guidance accuracy, on-orbit alignment, IMU-Drag Measurement-GNSS navigation, real-time integration guidance. guidance using wind information.

JAXA also has been studying rocket first stage recovery mission which uses reentry guidance using aerodynamics force until the final engine burn start. Issues of the reentry guidance of rocket first stage recovery are different from those of orbital recovery. The issues are followings.

(1)Short time of reentry guidance using aerodynamic force.

(2)High dynamics pressure of re-entry flight.

(3)How to combine aerodynamics reentry guidance and guidance using propulsion.

Since using aerodynamic reentry guidance might reduce the fuel consumption of rocket first state recovery, we have been investigating on reentry guidance for rocket first state recovery mission. This paper shows the difference between re-entry guidance for orbital recovery and those for rocket first state recovery. This paper also describes the issues of the reentry guidance for rocket first state recovery.
ТВЕРДЫЕ БЫТОВЫЕ ОТХОДЫ ГОРОДА ОШ И ПРОБЛЕМЫ ИХ УТИЛИЗАЦИИ
Authors: Болотбек Каримов , Аида Дурсунбаева , Алина Айбек кызы
Published: January 2024

В статье обобщены сведения о составе и объемов твердых бытовых отходов г. Ош.  Отмечено, что отсутствие стратегии управления отходами и необходимых подзаконных актов, несогласованные действия госструктур, тарифная политика служб, занимающихся саночисткой, не способствуют формированию устойчивой системы управления отходами. Дана санитарно-экологическая оценка современному состоянию мусорного полигона и рекомендованы рациональные пути их утилизации. Городская свалка г. Ош, функционирующая с 1975 года, исчерпала все свои ресурсы: будучи при строительстве запланирована на срок 15 лет, она эксплуатируется уже около 50 лет. При проектировании полигона небыли учтены не инженерно-геологический, не гидрогеологические условия местности. Строился он с нарушением санитарно-технических норм безопасности-хотя в проекте было заложено проведение работ по прокладке изолирующего слоя для предупреждения фильтрации токсичных веществ в грунтовые воды и почвенный слой.
Acute interstitial pneumonia post-COVID infection complicated by secondary bacterial pnuemonia
Authors:   Higher Specialist Trainee Respiratory and General Medicine in Mater Dei Hospital, Malta, Ceci Bonello Etienne
Published: January 2024

64-year-old lady presented to emergency with dyspnoea, fever, cough and green sputum production for the previous week. She had tested positive for SARS-cov-2 two weeks prior to the onset of these symptoms. Investigations including a Chest X-Ray (CXR) (Figure 1a) confirmed a lower respiratory tract infection
Acute myocardial infarction induced by migration of iodine-125 seeds
Authors:   Department of Cardiology, Shanghai Jiao Tong University Affiliated Sixth Peoples Hospital, Jin Xian
Published: January 2024

Iodine-125 seeds are used for brachytherapy of several tumors, which are considered to be relatively safe with rare complications.
9-year-old girl with TUBB4A dystonia
Authors:   Tabriz University of Medical Sciences, Tabriz, Iran., Mosaddeghi-Heris Reza
Published: January 2024

Whispering dystonia, also known as DYT-TUBB4A, is characterized by laryngeal dystonia and is linked to upper limb dystonia, cervical dystonia, and frequent generalization.
Atypical lipid keratopathy
Authors:   Department of Ophthalmology, Habib Bourguiba Hospital, Sfax, Tunisia, Mona Rekik
Published: January 2024

A 26-year-old patient, presented with a bilateral corneal clouding that had been slowly progressive over the last 2 years. He was a sports trainer having consumed protein for bodybuilding.
Acute reversible fulminant hepatitis associated with rifampicin
Authors:   Director, Institute of Pulmonology Medical Research and Development, A405, 4th Floor, Sangam, SV Road and Saibaba Road Junction, Santa Cruz (West), Mumbai 400054, India, Chhajed Prashant N
Published: January 2024

Tuberculosis in India contributes to significant endemicity, morbidity and mortality. Rifampicin is the most potent bactericidal drug used as a first line agent in the Anti-Tubercular Treatment (ATT) in rifampicin sensitive cases. Adverse effects of the ATT add to morbidity
Acute left vertebral artery dissection and right vertebral artery occlusion in a middle-aged man: A case report
Authors:   Faculty of Medicine, Mashhad university of Medical Science, Mashhad, Iran., Moradi Elnaz Vafadar
Published: January 2024

Spontaneous left Vertebral Artery Dissection (VAD) is an uncommon but very important etiology of acute posterior circulation stroke. We reported a case of a 43 years old man, who came with the complaint of chest pain with sudden onset, severe sweating
Tumor thrombosis in transit
Authors:   Echocardiography Research Center, Rajaie CardioVascular Medical & Research Center, Iran University of Medical Sciences, Tehran, Iran., Mohebi Somaye
Published: January 2024

Hepatocellular Carcinoma (HCC) is a poor prognosis cancer of liver which could be associated with venous thrombo-emboli but cardiovascular metastasis is rare; Here we present a case of HCC with tumor thrombosis and clot in transit who managed conservatively with anticoagulation.
A retrospective study of flap selection for through-and-through cheek defect reconstruction
Authors:   283 Tongzipo Road, Changsha City, Hunan Province, China., Hao Tian
Published: January 2024

This retrospective study compared different reconstructive strategies for through-and-through cheek defects arising from radical resection of buccal squamous cell carcinoma. Based on clinical data collected from March 2016 to September 2021
Insidious and lethal course of duodenal perforation in crohn’s disease with retroperitoneal abscess formation and right kidney necrosis
Authors:   Interventional Endoscopy, Hemato-Oncology, Diabetes and Metabolic Diseases, Malteser Waldkrankenhaus St. Marien, Rathsberger Str. 57, 91054 Erlangen, Germany, Kremenevski Igor
Published: January 2024

A 60-year-old woman with a long history of Crohn‘s disease and rheumatoid arthritis was admitted to the emergency department due to progressive severe cramping with abdominal pain (right upper quadrant), subfebrile temperature, and obstipation since 3 weeks. She had been treated by her rheumatologist for rheumatoid arthritis with certolizumab pegol, prednisolone and leflunomide
Performance Estimation of Copper-Free Solar Reflectors
Authors: Atak Eslem Enis , Wiesinger Florian , Kahraman Gülşah , Sánchez-Moreno Richardo , Günay A. Alperen , Baker Derek , Okutucu-Ozyurt Tuba
Published: January 2024

Copper (Cu) has been an essential ingredient in the production of silvered-glass reflectors used in the concentrated solar power (CSP) systems. However, due to added material cost and the environmental burden induced by Cu mining, researchers have started to look for ways to develop copper-free coating systems for reflectors used in solar thermal applications. In this study, we employed accelerated aging tests to obtain the aging characteristics of reflectors with and without Cu and exposed reflectors outside for natural aging. Samples were subjected to Copper Accelerated Acetic Acid Salt Spray (CASS), Ultraviolet-Humidity (UVH) and UV tests, and the changes in the hemispherical and specular reflectance were measured and compared.