Screening Of The Thermal Endurance Of Spacecraft Materials By Kinetic Modelling

2004 ◽  
Vol 851 ◽  
Author(s):  
M. Moser ◽  
S. Heltzel ◽  
C. O. A. Semprimoschnig ◽  
G. Garcia Martin
Keyword(s):  
Kinetic Modelling ◽  
European Space Agency ◽  
Polyimide Films ◽  
Technology Program ◽  
Model Free ◽  
Space Agency ◽  
Critical Materials ◽  
The One ◽  
The Given ◽  
Selection Of

ABSTRACTFuture science missions of the European Space Agency (ESA) to the inner part of the solar system will require the use of materials at an extreme radiation and temperature environment. A major concern regarding the selection of these materials is the thermal behaviour and the thermal stability. In this paper ways are shown to assess the thermal endurance of polymers by kinetic modelling. Two commonly used kinetic models, the one following the ASTM E 1641 and ASTM E 1877 standards and the other following the Model Free Kinetics (MFK) approach, are presented and compared to each other with the given example of two competing polyimide films, Kapton HN® of DuPont and Upilex S® of Ube Industries1, which were tested within ESA's critical materials technology program.

scholarly journals Applicability of NGGM near-real time simulations in flood detection

2019 ◽  
Vol 9 (1) ◽  
pp. 111-126
Author(s):  
A. F. Purkhauser ◽  
J. A. Koch ◽  
R. Pail
Keyword(s):  
European Space Agency ◽  
Earth System ◽  
The Earth ◽  
Future Mission ◽  
Space Agency ◽  
Flood Detection ◽  
The One ◽  
Real Time Simulations ◽  
Grace Mission ◽  
Gravity Mission

Abstract The GRACE mission has demonstrated a tremendous potential for observing mass changes in the Earth system from space for climate research and the observation of climate change. Future mission should on the one hand extend the already existing time series and also provide higher spatial and temporal resolution that is required to fulfil all needs placed on a future mission. To analyse the applicability of such a Next Generation Gravity Mission (NGGM) concept regarding hydrological applications, two GRACE-FO-type pairs in Bender formation are analysed. The numerical closed loop simulations with a realistic noise assumption are based on the short arc approach and make use of the Wiese approach, enabling a self-de-aliasing of high-frequency atmospheric and oceanic signals, and a NRT approach for a short latency. Numerical simulations for future gravity mission concepts are based on geophysical models, representing the time-variable gravity field. First tests regarding the usability of the hydrology component contained in the Earth System Model (ESM) by the European Space Agency (ESA) for the analysis regarding a possible flood monitoring and detection showed a clear signal in a third of the analysed flood cases. Our analysis of selected cases found that detection of floods was clearly possible with the reconstructed AOHIS/HIS signal in 20% of the tested examples, while in 40% of the cases a peak was visible but not clearly recognisable.

scholarly journals Science Observations with the IUE Using the One Gyro Mode

1990 ◽  
Vol 123 ◽  
pp. 517-520
Author(s):  
C. Imhoff ◽  
R. Pitts ◽  
R. Arquilla ◽  
C. Shrader ◽  
M. Perez ◽  
...  
Keyword(s):  
Control System ◽  
Attitude Control ◽  
European Space Agency ◽  
Attitude Control System ◽  
Sun Sensor ◽  
Space Agency ◽  
Current Attitude ◽  
International Ultraviolet Explorer ◽  
The One ◽  
Science Instrument

AbstractThe International Ultraviolet Explorer (IUE) is a geosynchronous orbiting telescope launched by the National Aeronautics and Space Administration (NASA) on January 26, 1978, and operated jointly by NASA and the European Space Agency. The science instrument consists of two spectrographs which span the wavelength range of 1150 to 3200 Å and offer two dispersions with resolutions of 6 Å and 0.2 Å. The spacecraft’s attitude control system originally included an inertial reference package containing 6 gyroscopes for 3-axis stabilization. The science instrument includes a prime and redundant Field Error Sensor (FES) camera for target aquisition and offset guiding. Since launch, 4 of the 6 gyroscopes have failed. The current attitude control system utilizes the remaining 2 gyros and a Fine Sun Sensor (FSS) for 3-axis stabilization. When the next gyro fails, a new attitude control system will be uplinked which will rely on the remaining gyro and the FSS for general 3-axis stabilzation. In addition to the FSS, the FES cameras will be required to assist in maintaining fine attitude control during target aquisition. This has required thoroughly determining the characteristics of the FES cameras and the spectrograph aperture plate as well as devising new target acquisition procedures. The results of this work are presented.

scholarly journals OPTIMIZATION OF THE LENGTH OF THE TOWING CABLE IN THE OPERATIONAL MAGNETOMETRIC SEARCH OF UNDERWATER OBJECTS

2021 ◽  
Vol 49 (2) ◽  
pp. 100-109
Author(s):  
B. A. Nersesov
Keyword(s):  
Magnetic Characteristics ◽  
New Approach ◽  
Probabilistic Values ◽  
Alternative Hypotheses ◽  
Underwater Object ◽  
Spatio Temporal ◽  
The One ◽  
New Generation ◽  
The Given ◽  
Selection Of

One of the features of the creation of a new generation of marine magnetometry means is the requirement to increase the efficiency of the search for emergency underwater objects due to a reasonable reduction in the length of the magnetometer towing cable, which ensures a decrease in the length of the search tack. Traditionally, the length of the cablerope of a towed magnetometer is determined taking into account its sensitivity, as well as the magnetic characteristics of the vessel-tug and underwater object. At the same time, the stochastic nature of the search process is ignored, caused by random factors (the uncertain spatial position of the underwater object in the search strip, as well as the orientation noise of the measuring platform). A new approach to the algorithm for processing the statistical information of the magnetometric signals of the underwater object and the towing vehicle in the search bar makes it possible to determine the optimal length of the towing cable. In this case, the problem of minimizing the objective function of the dependence of two alternatives is solved: on the one hand, a decrease in the towing noise as the tow cable length increases, on the other, an increase in the orientation noise caused by the spatio-temporal oscillations of the magnetometer. In addition, the evaluation of the selection of the signal of the underwater object against the background of the towing vehicle interference in terms of the "statistical discrepancy of alternative hypotheses" – the Kullback divergence, makes it possible to optimize the length of the cable-rope with the given probabilistic values of the detection of the underwater object.

General approaches to assessing the resistance to the effects of ionizing radiation of outer space for foreign electronic component base of development enterprises

2022 ◽  
Vol 14 (4) ◽  
pp. 58-66
Author(s):  
Aleksandr Kozyukov ◽  
N. Gamzatov ◽  
Sergey Grechanyy ◽  
Konstantin Zolnikov ◽  
I. Strukov ◽  
...  
Keyword(s):  
Radiation Resistance ◽  
Outer Space ◽  
European Space Agency ◽  
Electronic Component ◽  
Space Technology ◽  
Space Agency ◽  
Urgent Task ◽  
The Stability ◽  
Main Components ◽  
Selection Of

The analysis of information on the stability of the electronic component base (ECB) in the development of radio-electronic equipment (REE) of spacecraft (spacecraft) is an important and urgent task. The paper considers the main components of the approaches of foreign organizations developing radio space technology to ensure its radiation resistance. The design approaches of Thales Alenia Space, Airbus Defense and Space, and the European Space Agency are presented. The article outlines the main directions for optimizing the procedures for the preliminary selection of ECB, which consist in ensuring the required resistance of REE SC at the ECB level with ensuring the reliability of data on durability, in minimizing the costs of applying resistance enhancement measures (through the use of a promising ECB with increased resistance characteristics), to replace ECB.

scholarly journals Situational Awareness of Large Infrastructures Using Remote Sensing: The Rome–Fiumicino Airport during the COVID-19 Lockdown

2021 ◽  
Vol 13 (2) ◽  
pp. 299
Author(s):  
Andrea Pulella ◽  
Francescopaolo Sica
Keyword(s):  
Remote Sensing ◽  
Situational Awareness ◽  
European Space Agency ◽  
Optical Data ◽  
Activity Levels ◽  
Multispectral Data ◽  
Space Agency ◽  
Before And After ◽  
Spatio Temporal ◽  
The One

Situational awareness refers to the process of aggregating spatio-temporal variables and measurements from different sources, aiming to improve the semantic outcome. Remote Sensing satellites for Earth Observation acquire key variables that, when properly aggregated, can provide precious insights about the observed area. This article introduces a novel automatic system to monitor the activity levels and the operability of large infrastructures from satellite data. We integrate multiple data sources acquired by different spaceborne sensors, such as Sentinel-1 Synthetic Aperture Radar (SAR) time series, Sentinel-2 multispectral data, and Pleiades Very-High-Resolution (VHR) optical data. The proposed methodology exploits the synergy between these sensors for extracting, at the same time, quantitative and qualitative results. We focus on generating semantic results, providing situational awareness, and decision-ready insights. We developed this methodology for the COVID-19 Custom Script Contest, a remote hackathon funded by the European Space Agency (ESA) and the European Commission (EC), whose aim was to promote remote sensing techniques to monitor environmental factors consecutive to the spread of the Coronavirus disease. This work focuses on the Rome–Fiumicino International Airport case study, an environment significantly affected by the COVID-19 crisis. The resulting product is a unique description of the airport’s area utilization before and after the air traffic restrictions imposed between March and May 2020, during Italy’s first lockdown. Experimental results confirm that the proposed algorithm provides remarkable insights for supporting an effective decision-making process. We provide results about the airport’s operability by retrieving temporal changes at high spatial and temporal resolutions, together with the airplane count and localization for the same period in 2019 and 2020. On the one hand, we detected an evident change of the activity levels on those airport areas typically designated for passenger transportation, e.g., the one close to the gates. On the other hand, we observed an intensification of the activity levels over areas usually assigned to landside operations, e.g., the one close to the hangar. Analogously, the airplane count and localization have shown a redistribution of the airplanes over the whole airport. New parking slots have been identified as well as the areas that have been dismissed. Eventually, by combining the results from different sensors, we could affirm that different airport surface areas have changed their functionality and give a non-expert interpretation about areas’ usage.

scholarly journals Local competing in interpolation problems

2020 ◽  
Vol 11 (4) ◽  
pp. 99-122
Author(s):  
Sergej Vital'evich Znamenskij
Keyword(s):  
Metric Spaces ◽  
Rational Functions ◽  
Small Degree ◽  
Additional Parameter ◽  
General Terms ◽  
Interpolation Problems ◽  
Computational Simplicity ◽  
The One ◽  
The Given ◽  
Selection Of

A simple example illustrates the insufficiency of the known approaches to interpolation in the problem of recovering a function from a few given specific values that clearly convey the form. A local choice between polynomial and rational local interpolants, which minimizes the local interpolant’s errors at the nearest external nodes from one or different sides, complements the known approaches. It combines the extreme computational simplicity of local interpolants with the thorought selection of them. The principles of constructing the algorithm are formulated in general terms for mappings of metric spaces. They provide accurate (with rare exceptions) reconstruction of mappings that locally coincide with some of the given possible interpolants. In the one-dimensional case, the two-stage algorithm guarantees the continuity of the interpolant and accurately reconstructs polynomials of small degree, simple rational functions with a linear denominator, and broken lines of long links with knots at the ends when these requirements do not contradict each other. An additional parameter allows you to replace the exact restoration of polylines with the required smoothness of interpolation.

Pointing enhancement techniques for deep-space antennas

2010 ◽  
Vol 2 (2) ◽  
pp. 211-218 ◽  
Author(s):  
Piermario Besso ◽  
Maurizio Bozzi ◽  
Marco Formaggi ◽  
Luca Perregrini
Keyword(s):  
Computing Time ◽  
European Space Agency ◽  
Antenna Gain ◽  
Deep Space ◽  
Space Antenna ◽  
Space Agency ◽  
Space Antennas ◽  
Pointing Accuracy ◽  
Beam Waveguide ◽  
The One

The present paper presents a very efficient technique for enhancing the pointing accuracy in beam-waveguide (BWG) antennas and its application to the deep space antenna DSA2 of the European Space Agency. The proposed technique permits to achieve a twofold result: on the one hand, it provides a solution to the beam aberration issue, arising when the antenna simultaneously receives from and transmits to a spacecraft moving in the transversal direction. On the other hand, it allows to perform a fast conical scan to enhance the pointing accuracy of the antenna. Both results are achieved by simple linear displacements of feeds and mirrors located in the lower part of the BWG, with a very limited deterioration of the antenna gain. The required displacements of feeds and mirrors are determined through a fast optimization algorithm, based on a top-down approach, which requires repeated physical–optics analyses of the lower part of the beam waveguide only, with a significant reduction in the computing time.

scholarly journals GUASOM: an adaptive visualization tool for unsupervised clustering in spectrophotometric astronomical surveys

2021 ◽  
Author(s):  
M. A. Álvarez ◽  
C. Dafonte ◽  
M. Manteiga ◽  
D. Garabato ◽  
R. Santoveña
Keyword(s):  
European Space Agency ◽  
Unsupervised Classification ◽  
Analysis Tool ◽  
Visualization Tool ◽  
Self Organizing Maps ◽  
Astronomical Surveys ◽  
Space Agency ◽  
The One ◽  
Adaptive Visualization ◽  
Self Organizing

AbstractWe present an adaptive visualization tool for unsupervised classification of astronomical objects in a Big Data context such as the one found in the increasingly popular large spectrophotometric sky surveys. This tool is based on an artificial intelligence technique, Kohonen’s self-organizing maps, and our goal is to facilitate the analysis work of the experts by means of oriented domain visualizations, which is impossible to achieve by using a generic tool. We designed a client-server that handles the data treatment and computational tasks to give responses as quickly as possible, and we used JavaScript Object Notation to pack the data between server and client. We optimized, parallelized, and evenly distributed the necessary calculations in a cluster of machines. By applying our clustering tool to several databases, we demonstrated the main advantages of an unsupervised approach: the classification is not based on pre-established models, thus allowing the “natural classes” present in the sample to be discovered, and it is suited to isolate atypical cases, with the important potential for discovery that this entails. Gaia Utility for the Analysis of self-organizing maps is an analysis tool that has been developed in the context of the Data Processing and Analysis Consortium, which processes and analyzes the observations made by ESA’s Gaia satellite (European Space Agency) and prepares the mission archive that is presented to the international community in sequential periodic publications. Our tool is useful not only in the context of the Gaia mission, but also allows segmenting the information present in any other massive spectroscopic or spectrophotometric database.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Costumes and Choreography from Bodenwieser's Trunk: The Coat as Affective Memory

2019 ◽  
Vol 37 (1) ◽  
pp. 89-110
Author(s):  
Rachel Fensham
Keyword(s):  
Modern Dance ◽  
Human Condition ◽  
Personal Life ◽  
Creative Thought ◽  
Cain And Abel ◽  
Embodied Research ◽  
The Many ◽  
The One ◽  
Material Evidence ◽  
Selection Of

The Viennese modern choreographer Gertrud Bodenwieser's black coat leads to an analysis of her choreography in four main phases – the early European career; the rise of Nazism; war's brutality; and postwar attempts at reconciliation. Utilising archival and embodied research, the article focuses on a selection of Bodenwieser costumes that survived her journey from Vienna, or were remade in Australia, and their role in the dramaturgy of works such as Swinging Bells (1926), The Masks of Lucifer (1936, 1944), Cain and Abel (1940) and The One and the Many (1946). In addition to dance history, costume studies provides a distinctive way to engage with the question of what remains of performance, and what survives of the historical conditions and experience of modern dance-drama. Throughout, Hannah Arendt's book The Human Condition (1958) provides a critical guide to the acts of reconstruction undertaken by Bodenwieser as an émigré choreographer in the practice of her craft, and its ‘materializing reification’ of creative thought. As a study in affective memory, information regarding Bodenwieser's personal life becomes interwoven with the author's response to the material evidence of costumes, oral histories and documents located in various Australian archives. By resurrecting the ‘dead letters’ of this choreography, the article therefore considers how dance costumes offer the trace of an artistic resistance to totalitarianism.

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