European Cooperation For Space Standardization Research Articles

Analysis of the thermal design of a COTS-based modular battery system for satellites by thermal vacuum testing

AbstractThe qualification of components for satellite applications is a costly process due to the extreme conditions that must be endured in space. Therefore, space market access of battery technology innovations is often inhibited. However, modern battery technologies offer great advantages for satellite applications. In this work, a commercial off-the-shelf (COTS) based and modular lithium-ion battery system for satellites in Low Earth Orbit (LEO) is presented. A comparative analysis to evaluate system parameters and functionality of the proposed battery system and literature data is performed. A thermal vacuum test campaign is carried out to investigate the behaviour under LEO relevant conditions and to achieve qualification of the system performance according to the ECSS (European Cooperation for Space Standardization) standard. The tested system consists of two modules with 28 V nominal voltage and eight battery cells each. Experiments were conducted inside a vacuum chamber. The battery system was charged and discharged in temperatures from 0 °C to 45 °C in a high-vacuum for three weeks. The influence of the battery management electronics, the behaviour of the cells and the heating were analyzed. The cell temperatures stayed in the operating limit during 3.5 A and 10 A cycling. The battery system, however, exceeded the cell’s upper operating limit with a 40 °C baseplate and 3.5 A charging. Despite the dense system architecture with electronics between the cells the battery system can safely deliver power in a broad temperature range. Further investigations regarding safety and failure modes are necessary, along with advancements on software and state estimation algorithms.

NDT for qualification of space hardware made by additive manufacturing

X-Ray Computed Tomography (CT) has been established as the preferable NonDestructive Testing (NDT) method to detect inner defects in Metal Additive Manufactured (MAM) parts such as porosity, inclusions, lack of fusion, etc. Moreover, the usage of this manufacturing technology has grown in the aerospace sector due to the establishment of quality standards and the current maturity of the manufacturing systems, processing route and means of inspection. For instance, the European Cooperation for Space Standardization has developed a specific standard (coordinated by the European Space Agency – ESA) for AM quality assurance, processing, and requirements in space applications (ECSS-Q-ST-70-80C) indicating that CT inspections shall be carried out especially for critical structural and functional components. Similarly, large OEMs (Original Equipment Manufacturers) have developed their own standards considering CT as a mandatory NDT method in critical parts, but also other techniques such as Penetrant Testing (PT), Digital Radiography (DR) or visual inspection (VI) are also considered necessary to assure the quality of the components. This works presents diverse applications examples of different NDTs for hardware qualification: Titanium brackets for CHEOPS space missions; Aluminium helix antenna for PROBA3; Aluminium brackets for JUpiter ICy moons Explorer mission (JUICE), the last; or other aeronautic components like Aluminium fairings for the Clean Sky 2 IADP demonstrator, and structural Titanium flap fittings of the RACER helicopter. The aforementioned cases will be analysed not only from the execution of the inspection, but also from the application of different standards and requirements, specifically developed for AM or adapted to this novel manufacturing technology.

Hardware qualification for scientific ballooning missions

The European Stratospheric Balloon Observatory (ESBO) initiative aims at simplifying the access to stratospheric balloon missions. We plan to provide platforms and support with instrument design in order to support scientists. During the design process, the inevitable question of qualification for the harsh flight conditions arises. Unfortunately, there is no existing standard for qualification of stratospheric ballooning hardware. Thus, we developed a qualification procedure for use within ESBO and similar projects.In this paper, we present our analysis of the environmental conditions in the stratosphere. While conditions at typical balloon float altitudes are similar to the space environment, there are also some relevant differences. For example, the thermal environment is dominated by radiation and thermal conduction, but the remaining atmosphere still supports a certain amount of convection. The remaining atmospheric pressure in the stratosphere also leads to reduced arcing distances. Vibrational loads are far less than for space missions, but quasi-static or shock loads may occur. The criticality of radiation increases with mission duration.Based on the environmental conditions, we present the qualification procedures for ESBO, which are based on the European Cooperation for Space Standardization (ECSS) standards for space systems. Overtesting against too high requirements leads to overengineering, driving mission cost and mitigating the advantages of balloons over space missions. Therefore, we modified the ECSS standards to fit typical scientific ballooning missions over several days at altitudes up to 40 km. Furthermore, we analyzed design rules for space systems with regard to their relevance for scientific ballooning, including material and component selection. We present the experience from the hardware qualification process for the ESBO prototype STUDIO (Stratospheric UV Demonstrator of an Imaging Observatory). Even though boundary conditions are different for each individual mission, we aimed for a broader approach: We investigated more general requirements for scientific ballooning missions to support future flights.

Numerical simulation and validation of MWCNT-CFRP hybrid composite structure in lightweight satellite design

Aluminum alloy is generally used in electronic housings of satellites in space avionics due to its remarkable mechanical, thermal, electrical, and radio-frequency shielding properties. This paper proposes a design for a lightweight multi-functional electronic housing made from plastic containing multi-wall carbon nanotubes (MWCNT) composite material. The structural design of housings was validated against a set of boundary conditions and requirements of launch and space environments as prescribed by European Cooperation for Space Standardization (ECSS) standards. The proposed concept for lightweight composite housing was designed with special emphasis on reducing machining operations. The composite housing offers a mass saving of ∼25 % over a typical aluminum housing with similar mechanical performance in the three orthogonal directions. The modal frequency is greater than 100 Hz qualifying the design requirement for satellite electronic housings. Under sinusoidal vibration loads, the structure shows no noticeable excitation in acceleration response graph, indicating no resonance in low-range frequencies from 5 to 100 Hz. Maximum stresses obtained from Quasi-static and random vibration loads are within the tensile strength limit in the three orthogonal directions. In addition, maximum deflection observed in electronic printed circuit boards is within the 1 mm design requirement.

The International Reference Ionosphere Model: A Review and Description of an Ionospheric Benchmark

AbstractThis paper is a review of the International Reference Ionosphere (IRI) project and model. IRI is recognized as the official standard for the Earth's ionosphere by the International Standardization Organization, the International Union of Radio Science, the Committee on Space Research, and the European Cooperation for Space Standardization. As requested by these organizations, IRI is an empirical (data‐based) model representing the primary ionospheric parameters based on the long data record that exists from ground and space observations of the ionosphere. The core model describes monthly averages of the electron density, electron temperature, ion temperature, and ion composition globally in the altitude range from 60 to 2,000 km. Over time additional parameters were added in response to requests from the user community, this includes the equatorial ion drift, the occurrence probability of spread‐F and of an F1 layer, auroral boundaries and the electron content from the bottom of the ionosphere to user‐specified altitude. IRI has undergone extensive validations and is used for a wide range of applications in science, engineering, and education. This review is the result of many requests we have received for a comprehensive description of the model. It is also meant as a guide for users who are interested in a deeper understanding of the model architecture and its mathematical formalism.

Proton Spectra for the Interplanetary Space Derived From Different Environmental Models

Knowledge about the space radiation environment is crucial for the design and selection of materials and components used for space applications. This environment is characterized not only by the Sun’s electromagnetic radiation but also by charged particles categorized into solar wind, solar energetic particles (SEP) and galactic cosmic rays (GCR). Especially for material engineering and qualification testing, differential and integral spectra for particle energies ranging from keVs to GeVs are required. Up to now, a wide variety of models is available, whereas it is difficult to keep the overview. Although, e.g., the European Cooperation for Space Standardization (ECSS) standard includes instructions on how to investigate particle radiation, it does not provide an overall view. This paper shall support those in need of a comprehensive overview and provide comprehensive information about proton radiation spectra that can potentially be of use for space engineering tasks ranging from mission analysis to material and component design as well as qualification testing. The publicly accessible platforms OLTARIS, SPENVIS, and OMERE were examined for available proton spectra to be used. Exemplary, the particle radiation of solar cycle 23 is considered, which comprehends the years 1996–2008. A common drawback of the available models is their restriction to the MeV-range. Particularly when materials are directly exposed to the space environment, low energetic particles, specifically, the keV-range, are of high interest, since these particle transfer all their energy to the material. Therefore, additional data sources were used in order to include the usually neglected low energy protons into the derived spectrum. The data was transferred to common set of units and eventually could be compared and merged together. This includes a comparison of the most common models, incorporating data foundation, applicability, and accessibility. As a result, extensive and continues spectra are fitted that take all different models with its different energies and fluxes into account. Each covered year is represented by a fitted spectrum including confidence level as applicable. For solar active and quite times spectra are provided.

Novel Prediction Methods of Multicarrier Multipactor for Space Industry Standards

Multipactor prediction methods are of high relevance for the space industry in order to prevent its appearance during the design phase of RF high-power components. Up to the present time, prediction for multicarrier signals has been covered by an empirical rule, the 20-gap-crossing rule (20GCR), proposed in the 2003 version of the multipactor standard published by the European Cooperation for Space Standardization (ECSS). The 20GCR has been widely used by the space industry, although some studies have demonstrated that it might be inaccurate in some situations. The latest version of the ECSS multipactor standard, published in 2020, presents two novel methods for multipactor prediction with multicarrier signals: the pulsed method and the envelope sweep (ES) method, both simple, accurate enough, and suitable for industry standards. While the pulsed model is a simple and fast method based on a 1-D analytical theory, the ES method is more accurate and able to deal with real 3-D microwave structures. This article details both multipactor prediction methods, as well as their practical validation with a large dataset from previous analytical studies and experimental activities.

Developments in Aerospace Software Engineering practices for VSEs: An overview of the process requirements and practices of integrated Maturity models and Standards

As part of the evolution of the Space market in the last years – globally referred to as Space 2.0 - small companies are playing an increasingly relevant role in different aerospace projects. Business incubators established by European Space Agency (ESA) and similar entities are evidence of the need of moving initiatives to small companies characterized by greater flexibility to develop specific activities. Software is a key component in most aerospace projects, and the success of the initiatives and projects usually depends on the capability of developing reliable software following well-defined standards. But small entities face some difficulties when adopting software development standards that have been conceived thinking on larger organizations and big programs. The need of defining software development standards tailored to small companies and groups is a permanent subject of discussion not only in the aerospace field, and has led in recent years to the publication of the ISO/IEC 29110 series of systems and software engineering standards and guides, aimed to solve the issues that Very Small Entities (VSEs) () – settings having up to twenty-five people -, found with other standards like CMMI® or SPICE. This paper discusses the tailoring defined by different aerospace organizations for VSEs in the aerospace industry, and presents a conceptual arrangement of the standard based on meta-modeling languages that allow the extension and full customization with the incorporation of specific software engineering requirements and practices from ECSS (European Cooperation for Space Standardization).

High Energy Rapid Modular Ensemble of Satellites Payload Thermal Analysis Using OpenFOAM

In a space mission design, the goal of the thermal control subsystem is to ensure that all components of the satellite stay within their operating temperature ranges. The problem becomes more critical if the mission involves nanosatellites with an astrophysics payload requiring a dedicated thermal design to keep it at low temperature, as in the case of the High Energy Rapid Modular Ensemble of Satellites mission. Therefore, a thermal analysis is performed using ESATAN, one of the most-used software packages among those suggested by the European Cooperation for Space Standardization. This gives a good overview of the temperature fields, but many geometrical simplifications must be introduced in the model and all thermal interfaces must be checked. In order to assess the effect of the latter, the ESATAN results are cross checked with those obtained using another software, OpenFOAM, in which the geometry is created directly from the computer-aided-design model of the satellite, resulting in a very accurate geometrical representation. By first comparing the view factor calculations against analytical test cases, some issues emerged. These are thoroughly analyzed and discussed, and it is finally shown that they do not affect the temperature field. The high level of detail of OpenFOAM highlighted interesting possible improvements in the thermal configuration of the satellite.

A Proposal of a Life-Cycle for the Development of Sounding Rockets Missions

Suborbital flight experiments, carried out through sounding rockets, have been employed for scientific and technological research since the beginning of the space age, in the late 1950s. In Brazil, sounding rocket campaigns have been carried out since 1965, when the Centro de Lançamento Barreira do Inferno (CLBI) began its operation, having the Instituto de Aeronáutica e Espaço (IAE) as the primary provider of vehicles. IAE has also provided vehicles for international programs, such as the TEXUS and MASER microgravity programs, implemented by the European Space Agency (ESA), with launching campaigns based in the European territory. To implement each Brazilian mission that uses IAE’s sounding rockets, a set of activities focused on mission objectives is planned and implemented. Although structured and executed quite similarly to a project, such sounding rocket campaigns do not have their complete life-cycle studied and formally described in phases, review meetings, management processes and verification and validation philosophy. In the present work, the attempt has been to characterize a sounding rocket mission as a project and then, based on European Cooperation for Space Standardization (ECSS) standards, propose a reduced life-cycle to develop such projects, tailored to meet Brazilian sounding rocket missions. The proposed life-cycle, adapted to Brazilian sounding rocket missions, is then compared with two other sounding rocket campaigns life-cycles: one from the European Programme for Life and Physical Sciences in Space and the other from the National Aeronautics and Space Administration (NASA) sounding rocket program. The study and availability of a framework for implementing and managing sounding rocket missions will improve the reliability of such endeavors and speed up their organization.

Study on Vibration and Thermal Characteristics Applying Staking to CCGA Package for Space Applications

This paper describes the stacking effect for Ceramic Column Grid Array(CCGA) packages used for satellites. Reflow Soldering Process suitable for CCGA package with back structure was set as the process development goal to meet European Cooperation for Space Standardization(ECSS) standard. After analyzing the stacking effect according to the type of CCGA, it is verified by applying it to the CCGA Reflow Soldering Process. In order to confirm the validity of the staking effect analyzed in terms of vibration and thermal characteristics, it is verified through actual specimen production. It analyzes the cause of crack occurrence in the CCGA package and estimates the crack generation point using previously acquired inspection data. Keywords: Corner Staking, CCGA Package, Reflow Soldering Process, Crack, Vibration

Determination of the topology of lithium-ion battery packs for space equipment and validation through experimental investigation

Abstract Lithium-ion batteries are extensively used, not only for their advantages of high specific energy and durability but also for their light weight and robust structures, in many applications of space equipment, where severe mechanical vibration and shock conditions are encountered, especially during the launch, climb and stationing on the determined orbit. To design a robust battery pack that can withstand such loading conditions, a comprehensive investigation into the effects of such circumstances must be carried out both experimentally and computationally. In this study, four different battery topologies complying with the electrical requirements were compared according to various performance indicators. Then, the best prototype of the alternatives was chosen. The selected lithium-ion battery pack was examined with the help of resonance, harmonic and random vibration tests that were implemented according to the ECSS (European Cooperation for Space Standardization) standards. Additionally, a finite element model of the pack was prepared, and vibration simulations were run and compared with the experimental results. In the experimental work, it was observed that the battery-pack retained its structural integrity without experiencing any kind of mechanical failures. It was also observed that the outcomes of the finite element simulations are reasonably consistent with the test results.

Exploiting Orbital Data and Observation Campaigns to Improve Space Debris Models

The European Space Agency (ESA) has been developing the Meteoroid and Space Debris Terrestrial Environment Reference (MASTER) software as the European reference model for space debris for more than 25 years. It is an event-based simulation of all known individual debris-generating events since 1957, including breakups, solid rocket motor firings and nuclear reactor core ejections. In 2014, the upgraded version of the Debris Risk Assessment and Mitigation Analysis (DRAMA) tool suite was released. In the same year an ESA instruction made the standard ISO 24113:2011 on space debris mitigation requirements, adopted via the European Cooperation for Space Standardization (ECSS), applicable to all ESA missions. In order to verify the compliance of a space mission with those requirements, the DRAMA software is used to assess collision avoidance statistics, estimate the remaining orbital lifetime and evaluate the on-ground risk for controlled and uncontrolled re-entries. In this paper, the approach to validate the MASTER and DRAMA tools is outlined. For MASTER, recent observation campaign results shall be discussed. In DRAMA, the assessment of collision avoidance statistics is based on orbit uncertainty information derived from Conjunction Data Messages (CDM) provided by the Joint Space Operations Center (JSpOC). The way this information is going to be used in a future DRAMA version is outlined and the comparison of estimated manoeuvre rates with real manoeuvres from the operations of ESA spacecraft is shown.

APIS: the miniaturized Earth observation camera on-board OPTOS CubeSat

The athermalized panchromatic imaging system (APIS) was the low-resolution refractive camera proposed by the Laboratorio de Instrumentacion Espacial as a CubeSat payload. APIS flew on-board OPTOS CubeSat designed and developed by INTA using the methodology of European Cooperation for Space Standardization and space qualification tests. APIS had two main objectives: to analyze the performance degradation of commercial off-the-shelf (COTS) components due to space radiation and to verify in-flight functionality of the passive athermalization system. We summarize the design, manufacturing, and assembly integration and verification phases of the instrument, as well as the analysis of the radiation tests. Additional studies are included, such as thermal behavior, tolerances and sensitivity analysis, signal-to-noise ratio, and ghost images, as well as their implications during the design process. Three main goals were achieved during the mission lifetime: (1) the viability of a small refractive Earth observation camera on-board a CubeSat, (2) the validation for low Earth orbits of a passive athermalization system, and (3) the use of COTS elements, such as commercial glasses and detectors based on complementary metal–oxide–semiconductor technology, on a 2-year Earth observation mission.

IRI the International Standard for the Ionosphere

Abstract. This paper gives a brief overview over the International Reference Ionosphere (IRI) project and model. IRI is recognized as the official standard for the ionosphere by the International Standardization Organization (ISO), the International Union of Radio Science (URSI), the Committee on Space Research (COSPAR), and the European Cooperation for Space Standardization (ECCS). Of great importance are the external drivers of the model that help IRI to represent ionospheric conditions as realistically as possible. The paper discusses the drivers currently used presents recent improvements and changes. Besides the standard solar, magnetic, and ionospheric indices the paper also reports on the adjustment of the model with data and equivalent indices and on the progress towards a Real-Time IRI using data assimilation. IRI has been widely validated with many different data sources and has fared very well in community wide assessment studies. We present some of these studies and document the wide usages of the model in the scientific literature. Finally, we present an outlook on things to come in IRI-2018 and thereafter.

Automation of Quality Reports in the Aerospace Industry

Background: This document describes the implementation of an automated document-generation process for the creation of software-quality reports compliant with the European Cooperation for Space Standardization (ECSS) standards. Research statement: We propose a solution for the generation of technical documents that collect and aggregate data from different sources. In addition, we analyze the feasibility of building a solution that supports engineers in the generation of these complex artifacts. Situating the case: The structure and content of Software Product Assurance Milestone Reports and Software Verification Reports are defined in ECSS-Q-ST-80C and ECSS-M-ST-40C. Companies developing software for the European Space Agency must prepare these reports to detail development activities and the subsequent quality of software products. These reports incorporate data generated from different activities and managed with different software engineering tools. Case study: The automation techniques described in this paper were designed to create complex documents (quality and verification reports) based on the use of XML for data exchange and integration, and a set of connectors to collect software engineering data generated using different applications for requirements management, architectural design, testing, etc. Conclusions: The feasibility of the proposed solution was validated by applying it to two projects in the aerospace industry. The conclusion demonstrates that the automatic generation of complex documents from multiple sources of data is economically feasible and may produce benefits, including time to delivery and a significant reduction of production costs, by using existing XML-related technologies.

Open source implementation of ECSS CAN bus protocol for CubeSats

With the ever growing capabilities of space-grade FPGAs and microcontrollers, spacecraft systems are evolving from centralized architectures with a single main processing unit to decentralized layouts composed of multiple intelligent nodes. The backbone of this development is the command and control bus that interconnects these units. Used in terrestrial applications since decades, the CAN bus provides performance and robustness similar to other more traditional spacecraft buses such as MIL-STD-1553, but at very low cost. The European Cooperation for Space Standardization has published a standard in mid 2015 that specifies the requirements for a CAN bus system for space application. In this paper we present the details and results of a prototype implementation of this standard for CubeSat missions. We demonstrate that the minimal implementation of this protocol stack can well be adapted to the tight constraints of microcontrollers. The main advantages of this standardized CAN bus are increased reliability and higher data throughput, as compared to other commonly employed bus systems on CubeSats.

Agile Embedded System Development versus European Space Standards

Agile development methods are widely utilized in software development. There is a growing interest and effort to introduce them to other areas of technology, such as development of space systems. Space systems are typically safety- and mission-critical and therefore their development is strongly regulated and standardized. European Cooperation for Space Standardization (ECSS) has created a collection of standards which are extensively followed mainly in European space projects. In this paper, a review and discussion are presented to find out the conflicts between the agile development and the ECSS standards. The presented analysis and discussion show that the ECSS standards do not fully prevent the utilization of agile methods. However, there are aspects to be taken into account in the development methods, contracts and tailoring of standards.

Design of a Nanosatellite Ground Monitoring and Control Software - a Case Study

The growing countries that have carried out the development of CubeSat missions for academic purposes do not offer aerospace engineering programs at their universities. This causes difficulties for traditional engineers upon the formal use of different standards and frameworks for aerospace development, such as the European Cooperation for Space Standardization and Space Mission Analysis and Design . One way in which traditional software engineers can easily understand the structure of an aerospace framework, in order to apply it on the development of CubeSat mission software parts, is comparing its most important elements in relation to the elements suggested by a more familiar method. In this paper, we present a hybrid framework between the ECSS-E-ST-40C standard and the Rational Unified Process, which can be used by traditional software engineers as a guide model for the development of software elements in academic nanosatellite missions. The model integrates the processes and documentation suggested by the ECSS-E-ST-40C with the disciplines, workflows and artifacts suggested in Rational Unified Process. This simplifies the structure of ECSS-E-ST-40C and allows traditional software engineers to easily understand its work elements. The paper describes as study case the implementation of the hybrid model in the analysis and design of ground monitoring and control software for the Libertad-2 satellite mission, which is currently being developed by the Universidad Sergio Arboleda in Colombia.

Identification of Design Considerations for Small Satellite Remote Sensing Systems in Low Earth Orbit

The Sergio Arboleda University is preparing its next satellite mission, named Libertad 2. It will carry out a system of image acquisition as a working tool for researches based on the obtained data. Complete methodologies are often used in the development of satellite missions for planning, execution and deployment, for example, the standards of the European Cooperation for Space Standardization; these methodologies,however, do not include technical specifications or requirements for the development of nano-satellites nor for their subsystems.For this reason, this article focuses on the identification of the characteristics, requirements and restrictions, which must be considered in the design of a remote sensing system for satellites under the CubeSat standard, in order to serve as a starting point for the development of the main payload of the Libertad 2 mission.