Space Environment Information System Research Articles

Measurements of material erosion in space by atomic oxygen using the on-orbit material degradation detector

In recent years atomic oxygen (AO) has become a major challenge for the space community. AO is the most dominant species of the residual atmosphere in low Earth orbit (LEO). In addition, AO was found at the top of the Venusian and Martian atmospheres. As a result of exposure to AO, organic space-facing materials erode, leading to changes in their roughness, thermo-optical properties, and mass loss. In the past years, there has been a growing interest in very low Earth orbit missions, below an altitude of 350 km, where AO density and thus, AO flux, are extremely high. At these low altitudes, material degradation by AO erosion poses a great risk to the integrity of any space-facing material, unless well protected. As such, measuring the AO flux and the consequential material erosion by AO, in real-time while under actual space conditions, are of great interest to the space community.Thus, in this work we present real-time AO material erosion measurements that were conducted, for the first-time in LEO, using the on-orbit material degradation detector (ORMADD). The ORMADD is a low-cost and simple to operate detector, comprised of photovoltaic cells coated with semi-transparent AO sensitive coatings. Two ORMADDs were integrated on TAUSAT-1, a 3U CubeSat, deployed into LEO from the international space station. The first ORMADD was coated with a thin amorphous-carbon coating and the second was covered with a thick pyrolytic Kapton film. Using ORMADD, we were able to follow the erosion of the coatings in real-time conditions and calculate the AO flux in TAUSAT-1 orbit. The average in-orbit flux, derived from ORMADD data, was found to be comparable to the theoretical average AO flux calculated by the space environment information system (SPENVIS) software. This work demonstrates the abilities of ORMADD as a space environment detector, as well as a space material degradation research instrument.

Modelling the interaction of the Astro Bio Cube Sat with the Van Allen’s Belt radiative field using Monte Carlo transport codes

PurposeThe AstroBio Cube Satellite (ABCS) will deploy within the inner Van Allen belt on the Vega C Maiden Flight launch opportunity of the European Space Agency. At this altitude, ABCS will experience radiation doses orders of magnitude greater than in low earth orbit, where CubeSats usually operate. The paper aims to estimate the irradiation effect on the ABCS payload in the orbital condition, their possible mitigation designing shielding solutions and performs a preliminary representativity simulation study on the ABCS irradiation with fission neutron at the TAPIRO (TAratura Pila Rapida Potenza 0) nuclear research reactor facility at ENEA.MethodsWe quantify the contributions of geomagnetically trapped particles (electron and proton), Galactic Cosmic Rays (GCR ions), Solar energetic particle within the ABCS orbit using the ESA’s SPace ENVironment information system. FLUKA (Fluktuierende Kaskade—Fluctuating Cascade) code models the ABCS interaction with the orbital source.ResultsWe found a shielding solution of the weight of 300 g constituted by subsequent layers of tungsten, resins, and aluminium that decreases on average the 20% overall dose rate relative to the shielding offered by the only satellite’s structure. Finally, simulations of neutron irradiation of the whole ABCS structure within the TAPIRO’s thermal column cavity show that a relatively short irradiation time is requested to reach the same level of 1 MeV neutron Silicon equivalent damage of the orbital source.ConclusionsThe finding deserves the planning of a future experimental approach to confirm the TAPIRO’s performance and establish an irradiation protocol for testing aerospatial electronic components.

Effect of Atomic Oxygen on LEO CubeSat

Atomic oxygen (AO) is a major threat to satellites in Low Earth Orbits (LEO). AO causes serious damage to satellites such as erosion, corrosion and damage to almost all satellites surfaces. This study presents numerical prediction for the space environment effects on NARSSCube satellite using ATOMOX module in Space ENVironment Information System (SPENVIS) online simulation tools. Indeed, the prediction of erosion yields of NARSSCube structure induced by AO flux in LEO with different models is calculated. NRLMSISE model shows the highest mass and thickness loss for the outer surfaces of the satellite in all worst-case scenarios. A comparative study, for the erosion yields of some materials using SPENVIS, MISSE2 and other calculations, is presented. This research recommends the necessity of developing a database for all materials used in space providing all data for the effect of AO on each material in addition to the erosion depth and mass loss.

Investigating Space Radiation Environment Effects on Communication of Razaksat-1

This study attempted to identify whether space radiation sources could have affected the communication on RazakSAT-1 that was orbiting in a Low Earth Orbit-Near Equatorial (LEO-NEqO). Data on galactic cosmic rays (GCR), trapped protons, trapped electrons, and solar energetic particles (SEPs) obtained from Space Environment Information System (SPENVIS)are considered. The effects of these radiation sources are analyzed using the linear energy transfer (LET), total ionizing dose(TID), and solar cell degradation. Flux data from National Oceanic and Atmospheric Administration (NOAA) 15, 16, and 17 satellites, and the geomagnetic conditions during the time when RazakSAT-1’s missing is also analyzed. Another two satellites, Satelite de Coleta de Dados (SCD-2) and Advanced Land Observation Satellite (ALOS), are compared with the performance of RazakSAT-1. Results showed that GCR dominated at a high energy range of 103 MeV and above in the LEO-NEqO, whereas the energies of the trapped protons and trapped electrons are less than 400 MeV and 4 MeV, respectively. There are no SEPs estimated during the mission period (2009 – 2011). Based on the SPENVIS, SCD-2 and ALOS are more exposed to higher radiation damage than RazakSAT-1. Thus, an analysis of space radiation environment effects on the RazakSAT-1 communication lost after one year of operation will be discussed further, as a platform to fi nd the best strategy for future missions.

The Solar Accumulated and Peak Proton and Heavy Ion Radiation Environment (SAPPHIRE) Model

A new probabilistic model aiming to cover all aspects of the solar energetic particle (SEP) environment required for mission specifications is presented; the solar accumulated and peak proton and heavy ion radiation environment model. This model includes an updated reference data set upon which the analysis is based, a thorough evaluation of fitting procedures for SEP fluxes, a probabilistic helium model not based on proton fluxes, an extension to heavier ions based on new analysis of the Advanced Composition Explorer/solar isotope spectrometer data set, and a careful extrapolation of all output spectra to cover energies from 0.1 MeV/nuc to 1 GeV/nuc. Also included in this paper are derivations of spectra for rare solar particle events, which would occur at a given mean frequency and a new description for implementing the model to make it accessible to the public through systems, such as SPace ENVironment Information System or OMERE.

Simulation of major space particles toward selected materials in a near-equatorial low earth orbit

A low earth orbit near the equator (LEO-NEqO) is exposed to the highest energies from galactic cosmic rays (GCR) and from trapped protons with a wide range of energies. Moreover, GCR fluxes were seen to be the highest in 2009 to 2010 when communication belonging to the RazakSAT-1 satellite was believed to have been lost. Hence, this study aimed to determine the influence of the space environment toward the operation of LEO-NEqO satellites by investigating the behavior of major space particles toward satellite materials. The space environment was referred to GCR protons and trapped protons. Their fluxes were obtained from the Space Environment Information System (SPENVIS) and their tracks were simulated through three materials using a simulation program called Geometry and Tracking (Geant4). The materials included aluminum (Al), gallium arsenide (GaAs) and silicon (Si). Then the total ionizing dose (TID) and non-ionizing dose (NIEL) were calculated for a three-year period. Simulations showed that GCR traveled at longer tracks and produced more secondary radiation than trapped protons. Al turned out to receive the lowest total dose, while GaAs showed to be susceptible toward GCR than Si. However, trapped protons contributed the most in spacecraft doses where Si received the highest doses. Finally, the comparison between two Geant4 programs revealed the estimated doses differed at \(<18\%\).

Proton radiation damage assessment of a CCD for use in a Ultraviolet and Visible Spectrometer

This paper describes the radiation environment and radiation damage analysis performed for the Nadir and Occultation for MArs Discovery (NOMAD) Ultraviolet and Visible Spectrometer (UVIS) channel launched onboard the ExoMars Trace Gas Orbiter (TGO) in 2016. The aim of the instrument is to map the temporal and spatial variation of trace gases such as ozone and dust/cloud aerosols in the atmosphere of Mars. The instrument consists of a set of two miniature telescope viewing optics which allow for selective input onto the optical bench, where an e2v technologies CCD30-11 will be used as the detector. A Geometry Description Markup Language model of the spacecraft and instrument box was created and through the use of ESA's SPace ENVironment Information System (SPENVIS) an estimate of the 10 MeV equivalent proton fluence was made at a number of radiation sensitive regions within NOMAD, including that of the CCD30-11 which is the focus of this paper. The end of life 10 MeV equivalent proton fluence at the charge coupled device was estimated to be 4.7 × 109 protons.cm−2; three devices were irradiated at different levels up a 10 MeV equivalent fluence of 9.4 × 109 protons.cm−2. The dark current, charge transfer inefficiency, charge storage, and cosmetic quality of the devices was investigated pre- and post-irradiation, determining that the devices will continue to provide excellent science throughout the mission.

Space radiation environment of ALSAT-2 and its degradation effect on InGaP/InGaAs/Ge solar cells

Surrounding the earth, and throughout outer space, significant levels of radiation particles exist. These particles include protons, electrons, heavy ions, and other forms of radiation. Different regions are known to contain different amounts of various types of particles with different energies, all having different effects on electronic devices. Therefore, when designing a space-based system, it is important to understand the environment in which the electronic system will operate and the radiation hazards that can be expected. In this paper we present an analysis of the radiation environment for the ALSAT-2 Algerian satellite that was launched in 2010, using Space ENVironment Information System (SPENVIS). The impact of the radiation on InGaP/InGaAs/Ge Emcore ATJ solar cells is investigated by calculating the degradation. Finally, the End of Life (EOL) performance of the solar cells is predicted.

Radiation Dose Analysis of Galactic Cosmic Ray in Low Earth Orbit/Near Equatorial Orbit

Space environment contained harmful radiation that posed risk to spacecraft orbiting the Earth. In this paper, we looked into radiation doses caused by galactic cosmic ray (GCR) towards satellites orbiting in low earth orbit (LEO) near Earth's equator (NEqO) and compared them with doses caused by solar energetic particles (SEP) and trapped particles to determine the damage level of GCR. The radiation doses included linear energy transfer (LET) and nonionizing energy loss (NIEL) through a 1mm gallium arsenide (GaAs) planar geometry by using Space Environment Information System (SPENVIS) method. The orbital data followed Malaysian Razaksat satellite at 685km altitude and 9° inclination during selected solar minimum and solar maximum from solar cycles 21 to 24. We found that trapped particles gave the highest LET and no SEP was detected in SPENVIS. The LET values tend to be higher during solar minimum for trapped particles and GCR, corresponding to their anti-correlated fluxes with the solar activity. However, the NIEL values for GCR in solar cycle 23 did not follow the anti-correlation pattern.

Highly Elliptical Orbits for Arctic observations: Assessment of ionizing radiation

The ionizing radiation environment was analyzed for a variety of potential Highly Elliptical Orbits (HEOs) with orbital periods ranging from 6h to 24h suitable to continuously monitor the Arctic region. Several models available from the ESA Space Environment Information System (SPENVIS) online tool were employed, including the new-generation AE9/AP9 model for trapped radiation. Results showed that the Total Ionizing Dose (TID) has a well-pronounced local minimum for the 14-h orbit, which is nearly identical to the overall minimum observed for the longest orbital period (24h). The thickness of slab aluminum shielding required to keep the annual TID below 10, 5 and 3.33krad (i.e. 150, 75 and 50krad for 15years of mission duration) for a 14-h orbit is 2.1, 2.7 and 3.1mm respectively. The 16-h orbit requires an additional 0.5mm of aluminum to achieve the same results, while the 24-h orbit requires less shielding in the order of 0.2–0.3mm. Comparison between the AE8/AP8 and AE9/AP9 models was conducted for all selected orbits. Results demonstrated that differences ranged from −70% to +170% depending on orbit geometry.The vulnerability to the Single Event Effect (SEE) was compared for all orbits by modeling the Linear Energy Transfer (LET) for long-term conditions and for the 5min “worst case” scenario. The analysis showed no preference among orbits with periods longer than 15h, and in order to keep the 14-h orbit at the same level, the shielding should be increased by ∼33% or approximately by 1mm. To keep the Single Event Upset (SEU) rate produced by the “worst case” event at the same order of magnitude as for the “statistical” long-term case, the thickness of aluminum should be as high as 22mm. The overall conclusion from a space environment point of view is that all HEO orbits with periods equal to or longer than 14h can be regarded as good candidates for operational missions. Therefore, selection of orbit should be based on other criteria, for example, uniformity of spatial coverage for meteorological imaging or the configuration of the ground network for data reception.

Simulation and analysis of the LUCID experiment in the Low Earth Orbit radiation environment

The Langton Ultimate Cosmic ray Intensity Detector (LUCID) experiment is a satellite-based device that will use five Timepix hybrid silicon pixel detectors to make measurements of the radiation environment at an altitude of approximately 635 km, i.e. in Low Earth Orbit (LEO). The experiment is due to launch aboard Surrey Satellite Technology Limited's (SSTL's) TechDemoSat-1 in 2014. The Timepix detectors, developed by the Medipix Collaboration, are arranged to form the five sides of a cube enclosed by a 0.7 mm thick aluminium "dome", and will be operated in Time-over-Threshold mode to allow the flux, energy and directionality of incident ionising radiation to be measured. To estimate the anticipated data rates with respect to these measurements, the LUCID experiment has been modelled using the GEANT4 software framework. As an input to these simulations, SPENVIS, ESA's Space Environment information system, was used to obtain the estimated flux of trapped protons and electrons in TechDemoSat-1's orbit with NASA's AP-8 and AE-8 models. A web portal, LUCIDITY, was developeded to allow school students from the LUCID Collaboration to manage SPENVIS flux spectra and GEANT4 input cards. The initial results reported here confirm that the LUCID's data transmission allowance is sufficient, and further work applying the techniques to more specific space radiation environments with a more sophisticated simulation is proposed.

Spatial Analysis of Galactic Cosmic Ray Particles in Low Earth Orbit/Near Equator Orbit Using SPENVIS

The space environment has grown intensively harmful to spacecraft and astronauts. Galactic cosmic rays (GCRs) are one of the radiation sources that composed of high energetic particles originated from space and capable of damaging electronic systems through single event upset (SEU) process. In this paper, we analyzed GCR fluxes at different altitudes by using Space Environment Information System (SPENVIS) software and the results are compared to determine their intensities with respect to distance in the Earth's orbit. The altitudes are set at low earth orbit (400 km and 685 km), medium earth orbit (19,100 km and 20,200 km) and high earth orbit (35,793 km and 1,000,000 km). Then, within Low Earth Orbit (LEO) near the equator (NEqO), we used altitude of 685 km to compare GCRs with the intensities of solar particles and trapped particles in the radiation belt to determine the significance of GCRs in the orbit itself.

Space radiation analysis: Radiation effects and particle interaction outside the Earth's magnetosphere using GRAS and GEANT4

In order to explore the Moon and Mars it is necessary to investigate the hazards due to the space environment and especially ionizing radiation. According to previous papers, much information has been presented in radiation analysis inside the Earth's magnetosphere, but much of this work was not directly relevant to the interplanetary medium. This work intends to explore the effect of radiation on humans inside structures such as the ISS and provide a detailed analysis of galactic cosmic rays (GCRs) and solar proton events (SPEs) using SPENVIS (Space Environment Effects and Information System) and CREME96 data files for particle flux outside the Earth's magnetosphere. The simulation was conducted using GRAS, a European Space Agency (ESA) software based on GEANT4. Dose and equivalent dose have been calculated as well as secondary particle effects and GCR energy spectrum. The calculated total dose effects and equivalent dose indicate the risk and effects that space radiation could have on the crew, these values are calculated using two different types of structures, the ISS and the TransHab modules. Final results indicate the amounts of radiation expected to be absorbed by the astronauts during long duration interplanetary flights; this denotes importance of radiation shielding and the use of proper materials to reduce the effects.

Simulations of the radiation environment at ISS altitudes

In order to evaluate and simulate the response of detectors, for measurements of radiation environment inside and outside the International Space Station (ISS), a model for the outside space radiation environment at the altitudes of ISS is required. This estimation can be performed by using e.g. one of the two web-based model packages: CREME96 (Cosmic Ray Effects on Micro Electronics) and SPENVIS (the SPace ENVironment Information System). The main goal of this work is to compare and evaluate these web interfaces and the results given in order to understand how these will influence the simulations of experiments on the ISS.

Development of a complex instrument measuring dose in the Van Allen belts

One of the many risks of long-duration space flights is the excessive exposure to cosmic radiation. The objectives of this project are to develop a complex instrument comprising a Geiger–Muller counter and a three-dimensional (3D) silicon detector telescope (TriTel) in order to characterise the cosmic radiation in the Van Allen belts and to determine the radiation quality factor and the dose equivalent when and where it is feasible. The research and development of TriTel began in the Hungarian Academy of Sciences KFKI Atomic Energy Research Institute several years ago. The instrument presented in this paper will be mounted onboard a European satellite (European Student Earth Orbiter, ESEO) in geostationary transfer orbit. Elements of the TriTel system, issues of the electronic block diagram, requirements for the mechanical construction and the main data processing algorithms have been analysed. Monte Carlo simulations have been performed in order to investigate the dead time behaviour of TriTel. In order to give a rough estimation of the expected fluxes of protons and electrons in orbit, calculations were made with the space environment information system online tool.

TriTel-S: Development of a complex dosimetry instrument for a satellite in geostationary transfer orbit

One of the many risks of long-duration space flights is the excessive exposure to cosmic radiation, which may have serious consequences particularly during solar flares and higher solar activity. Since space radiation mainly consists of charged heavy particles, the equivalent dose differs significantly from the absorbed dose. The objectives of this project, which began in the KFKI Atomic Energy Research Institute of the Hungarian Academy of Sciences several years ago, are to develop a three-dimensional silicon detector telescope ( TriTel) and to develop software for data evaluation of the measured energy deposition spectra. A version of TriTel will be installed onboard a European satellite (ESEO) in a highly eccentric orbit crossing, the Van Allen belts. The instrument will encounter high fluxes of trapped electron radiation in a considerable part of the orbit. In order to give a rough estimate of the expected fluxes and spectra of protons and electrons in orbit, calculations were made with the Space Environment Information System (SPENVIS) online tool. The number of electron coincidences and the deposited energy spectra of electrons were calculated with the Monte Carlo simulation-based software MUlti-LAyered Shielding SImulation Software (MULASSIS). The description of the instrument, the expected environment in orbit and the evaluation of the results of the preliminary simulations are discussed in this paper.

Analysis of the effects of simulated synergistic LEO environment on solar panels

The effects due to the LEO environment exposure of a solar array primary structure are here presented and discussed in detail. The synergistic damaging components featuring LEO environment are high vacuum, thermal cycling, neutral gas, ultraviolet (UV) radiation and cold plasma. The synergistic effects due to these environmental elements are simulated by “on ground” tests, performed in the Space Environment Simulator (SAS) at the University of Rome “La Sapienza”; numerical simulations are performed by the Space Environment Information System (SPENVIS), developed by the European Space Agency (ESA). A “safe life” design for a solar array primary structure is developed, taking into consideration the combined damaging action of the LEO environment components; therefore results from both numerical and experimental simulations are coupled within the framework of a standard finite element method (FEM) based design. The expected durability of the solar array primary structure, made of laminated sandwich composite, is evaluated assuming that the loads exerted on the structure itself are essentially dependent on thermo-elastic stresses. The optical degradation of surface materials and the stiffness and strength degradation of structural elements are taken into account to assess the global structural durability of the solar array under characteristic operative conditions in LEO environment.

An Introduction to Displacement Damage Dose Model and Its Applications

Photonics are increasingly used in space missions to promote performance of space burn system. The radiation issues for photonics are significantly different from those of Si digital microelec-tronics. It has been found that displacement damage effect is one of the most important damages for photonics used in space radiation environment and a few spacecraft anomalies have been attributed to displacement damage. So displacement damage have been studied seriously in recent year. In this paper, firstly the mechanism for displacement damage is introduced and the ways displacement damage affecting the performances of photonics are discussed; then displacement damage dose model which based on non-ionization energy loss is presented to predict the degradation of CTE in CCD, dark current in Si device and output power in solar cell. Finally, a program based on DDD model for CTE decline prediction in space environment is introduced. The difference between our prediction result with that of ESA SPace ENVironment Information System (SPENVIS) is less than 10%. In addition to that, the program can be used to evaluate the effect o shield for sensitive device and to convert the proton spectrum for a particular mission to a equivalent fluence at a specific proton energy. The study results will find widely applications in satellite radiation-harden design.

New radiation environment and effects models in the European Space Agency's Space Environment Information System (SPENVIS)

The European Space Agency (ESA) Space Environment Information System (SPENVIS) provides standardized access to models of the hazardous space environment through a user‐friendly Web interface, available at http://www.spenvis.oma.be/. SPENVIS is designed to help spacecraft engineers perform rapid analyses of environmental problems and, with extensive documentation and tutorial information, allows engineers with relatively little familiarity with the models to produce reliable results. SPENVIS is based on internationally recognized standard models and methods in many domains. It uses an ESA‐developed orbit generator to produce orbital point files necessary for many different types of problem. It has various reporting and graphical utilities and extensive help facilities. SPENVIS also contains an active, integrated version of the European Cooperation for Space Standardization Space Environment Standard, and access to in‐flight data. Apart from radiation and plasma environments, SPENVIS includes meteoroid and debris models, atmospheric models (including atomic oxygen), and magnetic field models. Recently, the radiation sources and effects module have been rewritten, providing enhanced mission analysis features, new radiation effects models, and streamlined navigation between various model pages.

Space Environment Information System for Mission Control Purposes - a Decision Support System based on an architecture for space weather services

The radiation environment encountered in space by satellites is extremely variable and depends mainly on the satellite position and space weather. Although models for the concerned processes are available, most of them only represent the average conditions and neglect the dynamics of the system. Accurate prediction of the radiation environment remains an unsolved problem. Space weather can cause manifold problems to spacecraft (S/C) components, such as degradation of sensors and solar arrays and changes in on-board memories by Single Event Upsets (SEU). The final effect is a degradation of the S/C overall performance and in extreme cases complete unavailability of services. When certain alarm conditions are reached, risk avoidance procedures may be invoked, e.g. switching off high voltages/biases/filters etc. and transition to protected operating modes. Once the detectors are off, there is just a rough estimation of when the conditions are safe again. Better prediction of radiation conditions and more accurate information could greatly improve these operations. Therefore it is necessary to monitor and predict the space weather effects and improve the space weather services. In this paper we present a system for correlation, monitoring and predicting of space weather data, which is being developed by UNINOVA (Institute for the Development of New Technologies, Caparica, Portugal) in the frame of the European Space Agency (ESA) project, Space Environment Information System for Mission Control Purposes (SEIS) project. This decision support system (DSS) provides Flight Control Teams with useful Space Weather information (past, current and future) to increase the ability to protect S/C components from hazardous events and therefore prolong the lifetime of satellites and their scientific return. The system design was inspired by traditional business oriented DSS, based on Data Warehousing storage techniques, which collect and integrate historical and real-time data from heterogeneous sources, e.g. Space Weather data providers, S/C Telemetry and Orbital data and historical SEU records. The services provided include exploration and correlation analysis of data by established OLAP (On Line Analytical Processing) techniques, and near real-time monitoring of S/C instruments susceptible to Space Weather conditions. The monitoring service will directly depend on a Knowledge Base (representation of the domain experts knowledge), allowing it to suggest appropriate recovery actions whenever possible S/C damaging conditions are identified. Additionally, the system will incorporate forecasting services of well-known and commonly used physical radiation models, as well as new prediction techniques based on nonlinear models such as Artificial Neural Networks. For more information, please refer to: http://www2.uninova.pt/ca3/en/project SEIS.htm I.D. is supported by FCT, Lisboa, Portugal under grant number SFRH/BPD/14628/2003.