Plenary - Spacecraft Operations and Space Weather

Dave Pitchford, Richard Horne, Hugh Evans
Thursday 21/11, 09:00 - 10:30 and 11:00 - 12:30

Space weather and the space environment are important issues for a spacecraft operator; from cradle - to - grave, the effects are considered and encountered during the design, build and operation of a spacecraft. This session is a coming together of the user and research communities. Space industry participants are encouraged to discuss their experiences of Space Weather and their end-user needs for data and services. The research community is asked to showcase work directed at this important user community. Topics to be covered include: the analysis of significant space weather events; modeling and forecasting to support spacecraft operations; hosted sensors as assets for both the user and research communities.

Oral contributions

Seq   Time   Title
1   09:00 Invited  Space Weather Warnings: When Should Operators Really Be Worried?
Monham, Andrew

As a spacecraft operator for the provision of high availability meteorological data services, EUMETSAT is finding itself increasingly bombarded with media reports of impending crisis, based upon detection of solar flares or coronal mass ejections. These reports tend to create a climate of uncertainty in the user community and across the organisation, evidenced by many enquiries as to what is going to be done to secure our space assets. From the operational perspective, the answer is consistently "do nothing". The benefit of the doubt is given to the assumed robustness of the satellite design and no protective counter measures are taken. Time and time again, the cry of "Wolf!" is heard, but to no consequence. But will the wolf really appear one day only to be ignored?

We are assuming the satellite is sufficiently radiation hardened, but would it cope with a once in a hundred years magnitude event, an event never seen before in the space age? Considering that a typical EUMETSAT programme may last two to three decades and service continuity capability may be impacted after the loss of a single satellite, operators need to understand the limitations of their satellite design more clearly.

Related to this, the operators also need to be able to comprehend the threat level posed by the space weather event in order to assess the possible impact on the spacecraft and have a clear decision process in place for taking counter measures. A comparison with the situation with debris avoidance is made, where the situation is well parameterised and uncertainty levels are given on the conjunction predictions, allowing a probabilistic analysis to be performed and thresholds set for taking avoiding actions or not. Can such a parameterisation and risk assessment process for space weather events be achieved?

As EUMETSAT is set to increase the number of GEO and LEO satellites in orbit in the coming years, and world communities are increasingly reliant on our data, we are examining how we can move towards a clear space weather operational risk management process.

Examples of EUMETSAT experience of space weather effects, as well as cooperative activities with partners are provided as background.

2   09:20 Invited  Space Environment Impacts on Geostationary Communications Satellites: Amplifier Anomalies and Solar Array Degradation
Lohmeyer, Whitney; Cahoy, Kerri

Energetic particles in our space environment can damage geostationary communications satellite systems. However, it is difficult to obtain satellite telemetry, which is required to accurately understand the causal relationship of space weather and satellite performance and to quantify the actual effects of the space environment on these satellites. We approach this challenge by teaming with two communications satellite operators, Inmarsat and Telenor, to acquire telemetry data. We analyze more than one million operational hours (~7 GB) of telemetry, and focus on amplifier anomalies and solar array degradation. For eight Inmarsat satellites, we compare 665,112 operational hours of housekeeping telemetry from two generations of satellites, designated Fleet A and Fleet B. Each fleet experienced thirteen solid-state power amplifier (SSPA) anomalies for a total of 26 anomalies from 1996 to 2012. We also collaborate with Telenor to analyze 344,496 operational hours of satellite telemetry from four unique satellites operating between 1997-2012. The Telenor satellites are equipped with a different type of amplifier, known as a traveling wave tube amplifier (TWTA). Our goals are to investigate possible relationships between the space weather environment, in terms of low-energy electrons, the Kp index, high-energy protons and electrons, and galactic cosmic rays, and the performance of geostationary communication satellites. Similarly, we wish to determine whether geostationary communication satellite telemetry can be used to infer observations of the space environment. We obtain space environment data from the OMNI2 database, the Geostationary Operational Environmental Satellite (GOES), the Solar Influences Data Center, and Los Alamos National Labs (LANL) geostationary satellites. We compare this data with the Inmarsat and Telenor telemetry to statistically understand the space environment at the time of anomalies, and for periods of up to two weeks prior to each of the satellite anomalies. We also examine the satellite telemetry, not just at the time of known anomalies, but as a comprehensive data set on its own, to assess whether satellite telemetry can accurately relay information on space environment activity and provide more subtle information about the satellite system itself. The goal of this work is to use geostationary satellite telemetry to better understand the effects of space weather on satellite systems to improve satellite performance as well as current and future satellite design.

3   09:40 Invited  Connecting the Other 3 Billion in a Relatively Unknown Space Radiation Environment
Robert, Morris

O3b Networks was founded in November 2007 to provide broadband connectivity to the "other 3 billion" who are without low latency access. As such, the constellation altitude was established such that the signal latency enables the end user to have the "feel" of fiber speed but with the reach of a satellite. The constellation orbit has an altitude of approximately 8,069 km about the equator. This relatively unknown region of the space environment required exceptional anticipation of the radiation environment and a conservative comprehensive satellite design all within reasonable economic constraints. The presentation shall review the developmental approach for the O3b satellite with respect to the radiation environment as well as the current design implementation status.

4   10:00 Invited  A Case for Miniature Targeted Space Weather Sensors
Likar, Justin; Bogorad, Alexander; Lombardi, Robert; Herschitz, Roman
Lockheed Martin Space Systems Company, UNITED STATES

Operation of miniaturized targeted space weather sensors aboard modern spacecraft adds value for all entities associated with space environment characterization or modeling, spacecraft operation, cost-optimized spacecraft design, and space weather situational awareness via,

  • Real-time situational awareness, anomaly detection, and resolution.
  • In situ natural environment characterization in the presence of the spacecraft.
  • Spacecraft-influenced or spacecraft generated environment characterization.
  • Increased spatial and temporal fidelity in improved environmental models and tools such as AE9 / AP9.

    A burgeoning small satellite (1 kg to 1000 kg) market, increased access to space, decreased size, weight, power, and cost of capable space environment or interaction detectors / instruments, and increased recognition of space weather impacts has resulted in a growing catalog of useful sensors whereby the challenge shifts to ensuring the sensors are flown - correctly - and data managed, disseminated, and utilized in a productive manner.

    Lockheed Martin Space Systems Company (LM SSC) has, collaboratively with spacecraft operators, operated a suite of targeted space weather sensors at geostationary orbit that has accumulated more than 75 equivalent-spacecraft-years on-orbit operation [1, 2]. A technical, and business-case, review of LM SSC sensors will be used to demonstrate a favorable Return On Investment (ROI) for modern spacecraft operators and manufacturers seeking increased technical capability / complexity, high reliability, and low-cost.

    The recent release of the AE9 and AP9 next generation natural space radiation environment model [3] (Ver. 1.04.001) enables spacecraft designers to probabilistically assess space radiation-related risks associated with space vehicle design. Initial published comparisons [3, 4] have yielded insightful results pertinent to spacecraft designers or operators seeking to optimize mission costs via low-thrust, or "All Electric", transfer to GEO (e.g. telecommunications missions) or MEO (e.g. navigation missions) or performing mission operations in such orbital locations. Candidly stated, we endeavor to place spacecraft, for increasingly longer durations, in regions where the best models are predicting a more severe environment. The present manuscript further illustrates the utility of distributed, targeted sensing by the inclusion of a general trade study, comparing trapped particle environments as determined by AE9 / AP9 and predecessor state-of-the-art models. The example trade studies also consider design and operational impacts associated with radiation dose and high-level design aspects of a modern spacecraft implementing a low-thrust, "All EP" transfer mission to MEO or GEO.

    1. Bogorad, A. L, et al. "On-Orbit Total Dose Measurements from 1998 to 2007 using pFET Dosimeters." Presented at 47th IEEE Nuclear and Space Radiation Effects Conference, 2010.
    2. Likar, J. J., et al. "Geosynchronous ESD Environment Characterization via in situ Measurements on Host Spacecraft." Presented at IEEE International Symposium on EMC, 2011.
    3. Huston, S. L., et al. "Comparisons of AE9 and AP9 with Legacy Trapped Radiation Models". Accepted for presentation at 50th IEEE Nuclear and Space Radiation Effects Conference, 2013.
    4. Lindstrom, C. D., et al. "Enhanced Proton Levels in Slot Region and Displacement Damage Effects on Solar Arrays." Presented at AGU Fall Meeting, 2012.

    5   11:00   The COMESEP Space Weather Alert System
    Rodriguez, Luciano1; Devos, Andy1; Bourgoignie, Bram1; Kraaikamp, Emil1; Nicula, Bogdan1; Bonte, Katrien2; Verbeeck, Cis1; Crosby, Norma3; Dierckxsens, Mark3; Calders, Stijn3; Kruglanski, Michel3; Veronig, Astrid4; Rotter, Thomas4; Temmer, Manuela4; Vrsnak, Bojan5; Dumbovic, Mateja5; Zic, Tomislav5; Calogovic, Jasa5; Vennerstrom, Susanne6; Kristoffer, Leer6; Malandraki, Olga7; Tziotziou, Kostas7; Patsou, Ioanna7; Lygeros, Nikos7; Dalla, Silvia8; Marsh, Mike8; Robbrecht, Eva1
    1Royal Observatory of Belgium, BELGIUM;
    2Centre for mathematical Plasma-Astrophysics, KU Leuven, BELGIUM;
    3Belgian Institue for Space Aeronomy, BELGIUM;
    4University of Graz, AUSTRIA;
    5Hvar Observatory, CROATIA;
    6Technical University of Denmark, DENMARK;
    7National Observatory of Athens, GREECE;
    8University of Central Lancashire, UNITED KINGDOM

    COMESEP is a new European space weather alert system. It consists of several interconnected tools that work together to analyse data and automatically provide alerts for geomagnetic storms and SEP radiation storms. The system is triggered by different solar phenomena, such as CMEs, solar flares and coronal holes. After the automatic detection in solar data of any of these transients, the different modules of the system communicate in order to exchange information. For example, an automatic CME detection (by CACTus) triggers the drag-based model of CME propagation in order to calculate arrival times to Earth. A database of model runs of a test particle SEP model is consulted to generate an SEP radiation forecast. Overall the system produces a series of coherent alerts that are then displayed online. In this talk the different tools and the general functioning of the system will be presented. This work has received funding from the European Commission FP7 Project COMESEP (263252).

    6   11:15   Potential Operational uses for Directional Observations of Solar Proton Fluxes at Geostationary Orbit
    Rodriguez, Juan1; Mazur, Joseph2; Green, Janet3; Kress, Brian4
    1University of Colorado, UNITED STATES;
    2The Aerospace Corporation, UNITED STATES;
    3National Oceanic and Atmospheric Administration, UNITED STATES;
    4Dartmouth College, UNITED STATES

    As stated in 1975, the original purpose of the U. S. National Oceanic and Atmospheric Administration (NOAA) in flying solar proton monitors at geostationary orbit was 'to monitor the radiation hazard to manned and unmanned operations in space, and the ionospheric effects at high latitudes, from solar protons and alpha particles produced during large flares.' These ends remain essentially unaltered; the successors to the original instruments continue to support the Solar Radiation Storm alerts issued by NOAA. The goal of the work reported here is to determine whether the directionality of current and future Geostationary Operational Environmental Satellite (GOES) solar proton measurements can be exploited to provide support to spacecraft operators beyond that currently provided by NOAA. Potential operational uses of this directionality include (1) more precise specification of solar proton fluxes at geostationary orbit and (2) real-time specification of solar proton fluxes inside geostationary orbit for enhanced situational awareness. Through GOES-7, the NOAA geostationary satellites were spin stabilized, and although the solar proton monitors were directional, their accumulation time was much longer than the satellite spin period, resulting in an approximately omnidirectional average of solar proton fluxes. Thus, for example, the October 1989 GOES solar proton fluxes used to define extreme proton events for spacecraft designers were effectively omnidirectional. Such is not the case with measurements from subsequent GOES satellites, which have been three-axis stabilized. The directional nature of these observations, often exhibiting pronounced east-west anisotropies, is now clear, as is their non-local nature, owing to the finite gyroradii (of order 1 Earth radius) of solar energetic protons at geostationary orbit. Starting with GOES-13, two solar proton detectors are flown on each satellite, one looking westward and one looking eastward. While the westward-observed fluxes are usually little affected by the cutoff effects of the geomagnetic field and therefore are used by SWPC for real-time alerts, the eastward-observed fluxes are strongly affected by magnetospheric currents associated with storms and substorms as well as the pressure balance between the solar wind and the magnetosphere. Therefore, future environmental specifications based on the directional GOES observations may benefit by accounting for the observed anisotropies. The non-local nature of the observations implies that GOES eastward observations are equivalent to remotely sensing some point well inside geostationary orbit and are therefore referred to as 'inner fluxes'. The location of these 'inner fluxes' has been investigated by comparing the GOES fluxes with solar proton fluxes measured on the NASA Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX), NOAA Polar Operational Environmental Satellites (POES) and EUMETSAT MetOp satellites in low-earth polar orbits (whose data latencies of order one orbital period inhibit real-time usage). Under relatively quiet conditions, such as those observed prior to the arrival of the shock ahead of the coronal mass ejection(CME), the GOES 'inner fluxes' match the fluxes in low-earth-orbit in a narrow geomagnetic latitude band around 65 degrees, with a weak day-night latitudinal asymmetry. If the solar wind dynamic pressure carried by the shock increases above 5 nPa, the dayside inner flux latitudes can increase up to 10 deg and the nightside inner flux latitudes decrease up to 5 deg, exhibiting a strong day-night asymmetry. The decrease in the ring current index Dst during the main phase of a geomagnetic storm is associated with a decrease in both the dayside and nightside inner flux latitudes. Therefore, a successful 'nowcast' of solar proton fluxes in the inner magnetosphere based on the GOES eastward solar proton observations will require ancillary real-time Dst and solar wind plasma data, or some proxy for these quantities, and will account for day-night asymmetries.

    7   11:30   Low Energy Electrons (5-50 keV) in the Inner Magnetosphere
    Ganushkina, Natalia1; Amariutei, Olga1; Pitchford, David2; Liemohn, Michael3
    1Finnish Meteorological Institute, FINLAND;
    2Power/Thermal Subsystems \& Spacecraft Survivability, SES ENGINEERING, LUXEMBOURG;
    3University of Michigan, Ann Arbor, MI, UNITED STATES

    The fluxes of low energy electrons with energies from about 5 to 50 keV are not usually analyzed in details when studying electron radiation belts. These fluxes constitute the low energy part of the seed population which is critically important for the radiation belt dynamics. Radiation belt models need to specify the flux at a low energy boundary at all L shells. Moreover, energetic electrons with energies less than about 100 keV are responsible for such a hazardous charging phenomena as surface charging. The electron flux at these energies varies significantly with geomagnetic activity and even during quiet time periods.

    Transport and acceleration of the low energy (5-50 keV) electrons from the plasma sheet to geostationary orbit were investigated. We modeled one rather quiet, non-storm event on November 24-30, 2011, when the presence of isolated substorms was seen in AE index. We used the Inner Magnetosphere Particle Transport and Acceleration Model (IMPTAM) with the boundary at 10 $R_E$ with Tsyganenko and Mukai boundary conditions for the electrons in the plasma sheet. The output of the IMPTAM modeling was compared to the observed electron fluxes in ten energy ranges (from 5 to 50 keV) measured onboard the AMC 12 geostationary spacecraft by the CEASE II ESA instrument. The variations of fluxes as observed by CEASE II ESA instrument onboard AMC 12 satellite during non-storm period are due to substorm activity. The behavior of the fluxes depends on the electron energy. We introduced the substorm-associated electromagnetic fields by launching several pulses at the substorm onsets during the modeled period. The IMPTAM driven by the observed parameters such as IMF By and Bz, solar wind velocity, number density and dynamic pressure and Dst index was not able to reproduce the observed peaks in the electron fluxes, when no significant variations are present in those parameters. The observed variations in the electron fluxes can be reproduced if the model parameters show changes big enough. The substorm-associated increases in the observed fluxes can be captured when substorm-associated electromagnetic fields are taken into account. Modifications of the pulse model used here are needed, especially related to the pulse front velocity and arrival time.

    8   11:45   Impact of Space Weather on Spacecraft Operations at ESA/ESOC
    Reid, Simon1; Kirsch, Marcus2; Pantaleoni, Mauro3
    1RHEA System S.A., BELGIUM;
    3RHEA System S.A., GERMANY

    The European Space Operations Centre (ESOC), located in Darmstadt Germany, hosts the mission control centres for the majority of European Space Agency (ESA) spacecraft and has done so for more than forty years. In addition, Launch and Early Orbit Phase (LEOP) phase for third party missions are regularly conducted. The operations of ESA's European Tracking Network of ground stations (ESTRACK) are also performed here.

    ESOC's full portfolio of missions (historical, operational and in development) represents a huge variety of mission types, ranging from low earth orbits, trajectories passing close to the sun and into the further depths of the Solar System. Each spacecraft is fundamentally affected by the environment in which it operates and the variations in this environment (the Space Weather).

    Each spacecraft and its payload is subject to various long term effects of effects of this environment, but also carry a significant risk of anomalies or damage caused perturbations resulting from solar storms and other phenomena. Naturally these effects are of prime concern to ESOCs operations teams, who are responsible for maintaining the long term health of the hardware in space.

    This presentation will give results of an informal survey of ESOC's Spacecraft Operation Managers (SOMs), detailing some of their experience of space weather events, some insight into how space weather effects their routine or standard procedures, together with some thoughts on future needs and potential new services offered by the Space Weather community.

    9   12:00   An Evaluation of the AP9/AE9 Radiation Belt Models for Application in an ESA Context
    Heynderickx, Daniel1; Truscott, P.R.2; Evans, H.3; Daly, E.J.3
    1DH Consultancy BVBA, BELGIUM;
    2Kallisto Consultancy Limited, UNITED KINGDOM;

    Since the beginning of the space age, considerable effort was invested in building models of the trapped proton and electron populations, culminating in the NASA AP-8 and AE-8 models which have been the de facto standards since the seventies. In the intervening years, there have been several new models created, but none with the coverage in energy or space provided by these original models. Recently, a new version of these models (preliminary called AP9/AE9) has been released with significantly improved capabilities and including a significantly greater quantity of data.

    The first usage of the AP9/AE9 model in radiation analysis applications has revealed significant differences with results obtained with older radiation belt models for some orbit types. Consequently, an ESA sponsored activity was started to validate the new model results against other radiation belt models and in situ datasets. In addition, the optimal implementation of the new models in existing ESA software packages and tools was investigated.

    The conclusions of the validation activity will lead to recommendations for updates to the ECSS-E-ST-10-04 space environment standard.

    10   12:15   Modelling the High-Energy Electron Flux throughout the Radiation Belts using the BAS Radiation Belt Model
    Glauert, Sarah A.; Horne, Richard B.; Meredith, Nigel P.
    British Antarctic Survey, UNITED KINGDOM

    The flux of relativistic electrons in the Earth's radiation belts is highly variable and can change by orders of magnitude on timescales of a few hours. Understanding the drivers for these changes is important as energetic electrons can damage satellites. The BAS radiation belt model is a physics-based model that has been developed to simulate the energetic electron flux throughout the radiation belts, incorporating the effects of radial transport, wave-particle interactions and collisions. It is now used to forecast the energetic electron flux as part of the EU-FP7 SPACECAST project. Here we apply a new version of the BAS model that includes better modelling of wave-particle interactions to a number of space weather events. We show that during quiet periods the new model of plasmaspheric hiss and lightning generated whistlers are responsible for the slot region between the inner and outer radiation belts where new satellites are planned to operate. During storms, the increase in electron flux is best reproduced when chorus waves are also included particularly for medium Earth orbit where GNSS satellites operate. Finally, we model changes in the outer boundary of the Earths magnetic field and show how these changes can cause rapid radiation belt losses much closer to the Earth that can affect satellites in MEO and GEO orbits.


    Seq   Title
    1   The Shielding Effect of Honeycomb Sandwich Panels and a Method for Consideration in Radiation Analysis for Space
    Mai, Wolfgang; Foerstner, Roger
    Universität der Bundeswehr München, GERMANY

    The shielding effect of honeycomb sandwich panels which are common in spacecraft structures could be relevant in terms of mass saving - especially on challenging missions like in Jupiter's radiation belts. An usual conservative approach was to neglect the mass of the honeycomb cores. On the other hand it is hardly impossible to model these panels for a complex spacecraft in detail.
    To enable the consideration of the honeycomb core material in a radiation analysis of a complete satellite, the shielding effect of these panels was investigated. This was done by modelling a small honeycomb sandwich panel with realistic core dimensions which was compared to a model, where the whole core mass was smeared on an extra plate placed between the cover sheets. These models were created in the GDML (Geometry Description Markup Language) format and then analysed with GRAS (Geant4 Radiation Analysis for Space), a Geant4-based radiation analysis tool provided by ESA. In the simulation the models were irradiated from a plane source with three different spectra (solar protons and trapped electrons in GEO, Jovian electrons in the JUICE Mission). Total dose was measured by two silicon targets placed on the backside of this setup and fluence through the panel was calculated too.
    The comparison of all results showed, that there is a remarkable shielding effect of the core material, although it is a bit lower than with a plate of full equivalent core mass. Therefore a correction factor of the usable mass for an equivalent plate could be given.

    2   Validating the BAS Radiation Belt Model with Giove-B Satellite Data
    Meredith, Nigel1; Horne, Richard1; Glauert, Sarah1; De Mola, Davide1; Evans, Hugh2
    1British Antarctic Survey, UNITED KINGDOM;
    2European Space Agency, NETHERLANDS

    The EU FP7 project SPACECAST uses the BAS radiation belt model to forecast high energy electron fluxes in the Earth's radiation belts and to provide an associated risk index for satellites in Earth orbit. Part of the project is model verification and this is particularly important in the heart of the Earth's outer radiation belt where the flux of energetic electrons are highest, and, potentially, most damaging. This is the region which is traversed by global positioning satellites such as the US GPS system and the developing European Galileo satellite navigation system. In this study we take output from the latest BAS radiation belt model and apply calibration curves to convert electron differential number flux to counts observed by SREM on Giove-B. We show comparisons of the SREM data with modelled count rates for L > 4.5 for a selection of geomagnetic storms.

    3   Upgrades on the Orbit Generator Tool for the new Spenvis-ng System
    Rivera, Angela1; Grande, Ignacio1; Heynderickx, Daniel2; Kruglanski, Michel3; Sanchez, Noelia1; Parrilla, Esther1
    1Deimos Space, SPAIN;
    2DH Consultancy, BELGIUM;

    In this paper we present the upgrades done for the Orbit Generator tool developed by DEIMOS in the context of SPENVIS-NG. The key objective of this ESA project (ESTEC Contract number: 4000104812) is the upgrading of the current SPENVIS system into a new web-based service-oriented distributed framework supporting plug-in of models related to the hazardous Space Environment. The Orbit Generator on SPENVIS-NG will be implemented making use of the experience gathered by the current Orbit Generator and adding improvements that, for example, allow both direct download of TLE data from available web servers or use of ephemeris information using ESOC LTOF and CCSDS OEM formats. The addition of these new features will entail the development of a new input model to interface the Orbit Generator with the newly developed system and models.

    4   The Recent Anomalities of Space Weather Characteristics Fixed by the Russian Federal Space Agency Monitoring System
    Anashin, Vasily1; Protopopov, Grigory1; Gaidash, Sergey2; Sergeecheva, Nataliya3; Tasenko, Sergey4; Shatov, Pavel4; Elushov, Ilya1
    1Institute of Space Device Engineering, RUSSIAN FEDERATION;
    2Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation (IZMIRAN), RUSSIAN FEDERATION;
    3S.P. Korolev Rocket and Space Corporation "ENERGIA", RUSSIAN FEDERATION;
    4Fiodorov Institute of applied geophysics, RUSSIAN FEDERATION

    The latest anomalous dose rate increasing events detected by the space radiation exposure on electronic components engineering Monitoring System elements are discussed. The subjects considered are the space-borne control of TID effects on electronic components, the space-borne and ground-based control of some space weather characteristics.
    The base component of space-born segment is set of TID sensors, operating on MNOSFET dosimetry principle. More than 36 TID sensors were placed onboard more than 18 spacecrafts at the circular orbit ~20000 km with inclination ~65° since October 2008.
    The analysis of the last flight data is presented. An anomalous increasing dose rate was observed on March, 2012 (as 100 times as more), on July, 2012 (as 11 times as more), on October, 2012 (as 14 times as more). The TID sensor data were compared with average dose rate from the International Space Station, ELECTRO electron flux, ground measurements of cosmic rays variations by Moscow Neutron Monitor and GOES proton and electron flux data. An excellent coincidence of TID sensor data with integral flux of GOES 2 MeV electrons and ELECTRO 2.3 MeV electrons for all these events was observed.
    The one can note the absence of abrupt increasing of dose rate at the MEO during the solar flare with proton flux increasing and without electron flux increasing at the GEO.
    The experimental dose rate values for 2009, 2010, 2011, 2012 years are presented. The experimental total dose value and the average dose behind the different aluminum shield types values were compared.

    5   Self-Consistent Monte Carlo Simulations of the Re-Acceleration of Protons in the Downstream Region of a Coronal Shock
    Afanasiev, Alexandr; Vainio, Rami
    University of Helsinki, FINLAND

    We present results of Monte Carlo simulations of proton re-acceleration in the downstream region of a coronal shock, which were carried out in the framework of the SEPServer project. This effect, as suggested by observations, can be important at the early (coronal) phase of gradual SEP events, producing various features in the observed characteristics, e.g. non-power-law energy spectra of particles. The results are obtained using our simulation model of interactions of protons with a spectrum of Alfvén waves. The model treats the wave-particle interactions self-consistently under the quasi-linear approximation and employs the full form of the quasi-linear resonance condition governing the interactions. The simulations reveal that the particle energy spectra developed due to the re-acceleration process can have different shapes, not necessarily a power-law one, depending on the initial ratio of the particle energy density to the wave energy density in the system.

    6   Comparison between Path Lengths Traveled by Solar Electrons and Ions in GLE Events in Solar Cycle 23
    Malandraki, Olga1; Tan, Lun2; Reames, Donald3; Ng, Chee4; Wang, Linghua5; Patsou, Ioanna1; Papaioannou, Athanasios1
    1National Observatory of Athens, GREECE;
    2Department of Astronomy, University of Maryland, College Park, MD 20742, UNITED STATES;
    3Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, UNITED STATES;
    4College of Science, George Mason University, Fairfax, VA 22030, UNITED STATES;
    5Department of Geophysics, Peking University, Beijing 100871, CHINA

    We have examined the Wind/3DP/SST electron and Wind/EPACT/LEMT ion data to investigate the path length difference between solar electrons and ions in the Ground-Level Enhancement (GLE) events in solar cycle 23.
    Assuming that the onset time of metric type II or decameter-hectometric (DH) type III radio bursts is the solar release time of non-relativistic electrons, we have found that within an error range of±10% the deduced path length of low-energy (~27 keV) electrons from their release site near the Sun to the 1 AU observer is consistent with the ion path length deduced by Reames from the onset time analysis. Furthermore, the solar longitude distribution and IMF topology of the GLE events examined are in favor of the coronal mass ejection-driven shock acceleration origin of observed non-relativistic electrons. We have also found an increase of electron path lengths with increasing electron energies. The increasing rate of path lengths is correlated with the pitch angle distribution (PAD) of peak electron intensities locally measured, with a higher rate corresponding to a broader PAD. The correlation indicates that the path length enhancement is due to the interplanetary scattering experienced by first arriving electrons. The observed path length consistency implies that the maximum stable time of magnetic flux tubes, along which particles transport, could reach 4.8 hr.

    7   Self-Consistent Plasma Simulations of Particle Acceleration and Radio Emission in the SEPServer Project
    Vainio, Rami1; Afanasiev, Alexander1; Battarbee, Markus2; Ganse, Urs1; Kempf, Andreas3; Kilian, Patrick3; Pönni, Arttu1; Spanier, Felix3
    1University of Helsinki, FINLAND;
    2University of Turku, FINLAND;
    3University of Würzburg, GERMANY

    Self-consistent plasma simulations in the framework of the SEPServer project were designed to aid the interpretation of the experimental results obtained from the analysis of the SEP events. We considered the acceleration of ions and electrons in coronal shocks, the acceleration of electrons in coronal current sheets and the radio emission through the plasma emission mechanism upstream of coronal shocks. Ion transport and acceleration was modeled under the quasi-linear approximation, i.e., as resonant interaction between the charged particles and the Alfvénic fluctuations carried by a prescribed large-scale plasma flow, using the CSA code (Vainio & Laitinen 2007: ApJ, 658, 622) and a new code (Afanasiev & Vainio 2013: ApJS, submitted) developed in the framework of SEPServer. Electron acceleration and radio emission was simulated using local plasma simulations making use of the Particle-in-Cell code ACRONYM (Kilian et al., High Performance Computing in Science and Engineering '11, 2012). In this paper, we will present a summary of the simulation work performed in SEPServer and discuss the implications of the simulation results in the light of data analysis performed in the project.

    8   New Data and Forecasting Products in the Framework of the EU FP7 Project SPACECAST
    Heynderickx, Daniel1; Horne, R.B.2; Meredith, N.P.2; Glauert, S.A.2; Boscher, D.3; Sicard-Piet, A.3; Maget, V.3; Ganushkina, N.4; Amariutei, O.4; Koskinen, H.5; Vainio, R.5; Afanasiev, A.5; Pomoell, J.6; Poedts, S.6; Sanahuja, B.7; Aran, A.7; Pitchford, D.8
    1DH Consultancy BVBA, BELGIUM;
    2British Antarctic Survey, UNITED KINGDOM;
    5University of Helsinki, FINLAND;
    6K.U. Leuven, BELGIUM;
    7Universitat de Barcelona, SPAIN;

    Solar activity can trigger sporadic bursts of energetic particles in the solar wind and increase the number of high and low energy particles trapped inside the Earth's radiation belts. These cause damage to satellites and are a hazard for manned spaceflight and aviation. They are difficult to predict due to uncertainties over the basic physical processes, and the need to access reliable data in real time.

    The SPACECAST project (European Union Framework Programme 7 Project 262468) aims to protect space assets from high and low energy particles in the electron radiation belts and during solar energetic particle events by developing European dynamic modelling and forecasting capabilities.

    SPACECAST uses a MySQL database server (using the ESA Open Data Interface under licence) operated by DH Consultancy to collect magnetic indices, solar wind parameters and GOES particle fluxes in near real time, and combines this with web services to distribute the data to model servers at NERC/BAS, ONERA and FMI, where model runs are executed to obtain forecasts of high energy electron fluxes and nowcasts of low energy electron fluxes in the radiation belts. The model results are collected by the DH Consultancy server, post-processed and displayed on the SPACECAST web site ( in the form of panel plots, movies and alerts (including a satellite risk index for GEO deep dielectric charging). All processes are fully automated and run at hourly intervals.

    Most recently, modelling of solar energetic protons and a service to calculate radiation doses have been added. In addition, alert services are being defined which can be tailored by registered users.

    9   Space Weather Services at the Belgian Institute for Space Aeronomy
    De Donder, Erwin; Kruglanksi, Michel; Messios, Neophytos; Calders, Stijn; Hetey, Laszlo; Chabanski, Sophie; Hallet, Stefaan
    Belgian Insitute for Space Aeronomy, BELGIUM

    In this poster we briefly outline the main activities of the Space Weather section, that is part of the Space Physics department of the Belgian Institute for Space Aeronomy. Through participation in several projects the Space Weather section has acquired a rich experience in developing and operating scientific services. One of our prime projects is SPENVIS (Space Environment Information System), which has been running at BIRA since 1996 and is now rebuild with new technologies in order to better meet the current and future needs of the user community. The new system is foreseen to be operated in the context of ESA's SSA programme. Also within this framework, the group actively participates in the operation of the SSA Space Weather Coordination Centre (SSCC) at the Belgian Royal Observatory.

    10   SEPServer Advances Overview on Solar Energetic Particle Events
    Malandraki, Olga E.1; Papaioannou, A.1; Agueda, N.2; Klein, K.-L.3; Heber, B.4; Valtonen, E.5; Nindos, A.6; Dresing, N.4; Herbst, K.4; Vainio, R.7; Braune, S.8; Kouloumvakos, A.6; Dröge, W.9; Kartavykh, Y.9; Rodríguez-Gasén, R.10; Vilmer, N.10; Heynderickx, D.11; Aurass, H.8; Hamadache, C.12; Kiener, J.12; Riihonen, E.5; Tatischeff, V.12; Sanahuja, B.2
    1Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory o, GREECE;
    2Dept. d¢Astronomia i Meteorologia and Institut de Ciéncies del Cosmos, Universitat de Barcelona, SPAIN;
    3LESIA-Observatoire de Paris, CNRS, UPMC, Univ Paris 06, Univ. Paris-Diderot, Paris, France, FRANCE;
    4Christian-Albrechts-Universität zu Kiel, GERMANY;
    5Space Research Laboratory, Department of Physics and Astronomy, University of Turku, FINLAND;
    6University of Ioannina, GREECE;
    7Department of Physics, University of Helsinki, FINLAND;
    8Leibniz-Institut für Astrophysik Potsdam (AIP), Potsdam, GERMANY;
    9Julius-Maximilians Universität Würzburg, Würzburg, GERMANY;
    10LESIA-Observatoire de Paris, CNRS, UPMC, Univ Paris 06, Univ. Paris-Diderot, Paris, FRANCE;
    11DH Consultancy, BELGIUM;
    12CSNSM, IN2P3-CNRS, Univ Paris-Sud, Paris, FRANCE

    SEPServer hosted activities related to the scientific analysis of SEP event observations, including data analysis using both data-driven and simulation-based methods. The scientific conclusions of this effort are drawn with the implementation and release to the SEP community of multiple SEP event catalogs based on different spacecrafts and instruments, covering a broad timescale from 1975 to 2013 as well as a variety of distances from 0.3 to ~5 AU in the heliosphere. SEP events from Helios A & B missions, going back to 1975, at distances 0.3-1 AU, together with their Electromagnetic (EM) counterpart from OSRA data are being released for the first time. A catalog covering solar cycle 23 based upon the Solar and Heliospheric Observatory (SOHO)/ Energetic and Relativistic Nuclei and Electron (ERNE) high-energy (~68 MeV) protons at 1 AU with parallel analysis of SOHO/ Electron Proton Helium Instrument (EPHIN) and Advanced Composition Explorer (ACE) / Electron, Proton and Alpha Monitor (EPAM) data, including the relevant EM associations has also been delivered. Furthermore, the first complete Solar TErrestrial RElations Observatory (STEREO) SEP catalog based on the Low Energy Telescope (LET) protons (6-10 MeV) and the Solar Electron Proton Telescope (SEPT) electrons (65-105 keV) covering the rising phase of solar cycle 24 has been implemented. Moreover, the Cosmic Ray and Solar Particle Investigation (COSPIN) Kiel Electron Telescope (KET) data of 38-125 MeV has been used to identify a new catalog of SEP events observed in and out of the ecliptic plane over solar cycle 23, with simultaneous analysis of electrons recorded by the Heliosphere Instrument for Spectra, Composition and Anisotropy at Low Energies (HISCALE). For selected cases simulation based analysis has been applied in order to identify the timing of the injection history and to provide a cross reference to the EM emissions, leading to a comprehensive treatment of these events and to the corresponding testing of the data-driven analysis methods. SEPServer brings together a wealth of SEP data, analysis methods and diverse but at the same time interconnected solar and heliospheric communities. It thus provides an open tool that will advance our understanding of SEP propagation and acceleration, under different conditions, an important element of Space Weather.

    11   Solar Energetic Particle Spectral and Compositional Invariance in the 3-D Heliosphere: Ulysses and ACE/WIND Comparisons
    Malandraki, Olga E.1; Tylka, Allan J.2; Ng , Chee K.3; Marsden, Richard G.4; Tranquille, Cecil4; Patterson, Doug5; Armstrong , Thomas P.5; Lanzerotti , Louis J.6
    1of Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, A, GREECE;
    2Science and Exploration Directorate, NASA/GSFC, Greenbelt, MD 20771, USA, UNITED STATES;
    3George Mason University, Fairfax, VA, USA, UNITED STATES;
    4European Space Agency/ESTEC, NETHERLANDS;
    5Fundamental Technologies Inc., USA, UNITED STATES;
    6New Jersey Institute of Technology, UNITED STATES

    We carry out the first detailed examination and comparison of elemental spectra and composition in the late decay phase of two Solar Energetic Particle (SEP) events in the so-called 'reservoir' regions, between spacecraft widely separated in latitude, as well as in longitude and radial distance in the Heliosphere. Energetic particle data from instruments onboard the Ulysses spacecraft located at a high heliospheric latitude of ~ 70 deg N and at a heliocentric distance of ~ 2.5 AU and from spacecraft at L1 are used in this work. Particle intensities over time are observed to be in close agreement following the shock passage over the widely separated spacecraft. Electron measurements were used to identify the extent of the particle reservoir. In this update on reservoir composition studies, we extend our previous work to sub-MeV/nucleon energies, using measurements from HI-SCALE on Ulysses and EPAM on ACE. Implications of the observations for models of SEP transport are also discussed.
    Acknowledgments: The presented work has received funding from the European Union FP7 project COMESEP (263252) and has also been supported by NASA under grants NNH09AK79I and NNX09AU98G (AJT).

    12   Modelling of Large Solar Energetic Particle Events for Space Weather Applications: Testing the Q(VR)-Relation
    Pomoell, Jens1; Aran, Angels2; Poedts, Stefaan1; Sanahuja, Blai2
    1KU Leuven, BELGIUM;
    2Universitat de Barcelona, SPAIN

    As a result of our previous modelling of gradual solar energetic particle (SEP) events, a relation known as the Q(VR)-relation between the injection rate of shock-accelerated particles, Q, and the jump in the radial velocity across the shock front, VR, at the cobpoint position (i.e. the position at the shock front to which the observer is magnetically connected during a SEP event) was established. Utilizing the relation a first space weather tool to predict proton fluxes and fluences at different locations in the heliosphere, the SOLPENCO tool, was constructed. Further developments of the physics-based model lead to an extended version of the tool, SOLPENCO2 (within the SEP model of the ESA/SEPEM project).

    As the Q(VR)-relation is the foundation upon which the aforementioned space weather tools are based, a better characterization of the relation is necessary in order to further improve the tools. This can be achieved by improving the accuracy of the modelled SEP events, as well by extending the number of modelled events.

    In this work, we present our modelling results of a selection of SEP events using a new shock-and-particle model. Our modelling approach consists of combining 1) a simulation of the propagation of a shock from the Sun to the Earth driven by a coronal mass ejection (CME) and 2) the transport of shock-accelerated particles along the interplanetary (IP) magnetic field line connecting the shock front with the observer at 1 AU.

    In particular, we have developed a new shock propagation model that utilizes numerical magnetohydrodynamic (MHD) simulations in the ecliptic plane for obtaining a realistic temporal evolution of the parameters of the propagating shock. This is ensured by choosing the free parameters of the model CME initialized at ~two solar radii in such a way that the observed plasma parameters at 1 AU as well as the transit time of the shock are accurately reproduced.

    Next, the results of the MHD simulation are used as input in a particle transport model, which is used in order to reproduce the proton differential intensity-time profiles (and first order anisotropies whenever possible) measured during the studied SEP events. Analyzing the output of the new coupled shock-and-particle model, we are able to address the Q(VR)-relation in detail.

    The work is performed in the framework of SPACECAST, a Collaborative Project funded by the European Union Framework 7 programme to help protect satellites on orbit by modelling and forecasting particle radiation.

    13   Evaluating the Effect of Proton Anisotropies in the Inner Heliophere: 2006 December 13 SEP Event Case Study
    Aran, Angels1; Vainio, R.2; Pönni, A.2; Sanahuja, B.1; Jacobs, C.3; Lario, D.4; Heynderickx, D.5; Daly, E.J.6; Jiggens, P.6; Lei, F.7; Truscott, P.R.8
    1Universitat de Barcelona, SPAIN;
    2University of Helsinki, FINLAND;
    3Space Applications Services NV/SA, BELGIUM;
    5DH Consultancy BVBA, BELGIUM;
    7RadMod Research Ltd, UNITED KINGDOM;
    8Kallisto Consultancy Limited, UNITED KINGDOM

    A missing ingredient in present solar energetic particle (SEP) environment empirical models is particle flux anisotropies. In the interplanetary space, anisotropies are obtained from particles pitch angle (i.e. the angle between the magnetic field and particle velocity). Directionality information of SEP intensities at high-energies (> 10 Mev) is relatively rare, mostly comes from 1 AU measurements, and pitch-angle coverage is usually limited. Hence, a purely empirical modelling of the effect of anisotropies on fluxes and fluences in the interplanetary medium does not, a priori, seem like a very reasonable approach. However, this information is essential to determine the radiation harness required on the different sides of a spacecraft.

    Alternatively, experimental data available can be used to determine omni-directional intensities and first-order anisotropies of SEPs as a function of time and energy. These data can then be fitted using a particle transport model which is able to reproduce the full angular distributions of SEPs, not only at the measurement position but at other locations in the inner heliosphere.

    In the context of the ESA IPRAM project (Interplanetary and Planetary Radiation Model for Human Spaceflight, ESA Contract No 4000106133/12/NL/AF), we have analysed the effect of anisotropies by modelling the large gradual SEP event during 13-14 December 2006. We use observations from ACE, SOHO and STEREO spacecraft. We have reproduced the observed proton differential intensities and anisotropies using a shock-and-particle model that combines the simulation of the propagation of the associated CME-driven shock from 4 solar radii up 1 AU and the simulation of the particle transport via the cobpoint concept.

    Using this model we have determined the pitch-angle distributions at several proton energies for virtual observers placed at 0.4 AU and 1.6 AU along the same magnetic field line as the 1 AU spacecraft. Next, we obtain the directional fluxes and fluences for these observers by folding in the temporal evolution of the direction of the local magnetic field (an estimate for the away from 1 AU observers) in order to obtain the full directional distribution of SEPs in a fixed coordinate system. The maximum-to-minimum ratios of the flux and fluence distributions as a function of the viewing direction were analysed. For this specific event, the results show that the variations of the radiation field during the time of maximum flux and integrated over time show little variation (a factor less than 1.7 for the fluence and a factor less than 3.4 for the peak flux) at distances > 1 AU. At 0.4 AU, however, the results yield substantial effects from the anisotropies, in some cases by a factor higher than 7.

    In conclusion, we recommend that a model for interplanetary flux anisotropies for distances shorter than 1 AU will be developed. It is peremptory for this purpose that the field direction is properly taken into account since the variability of the local magnetic field may be great enough to average out a part of the anisotropies.

    14   The Updated Solar Energetic Particle Environment Modelling Tool
    Crosby, Norma B.1; Heynderickx, Daniel2; Jiggens, Piers3; Aran, Angels4; Sanahuja, Blai4; Jacobs, Carla 5; Poedts, Stefaan5; Truscott, Pete6; Lei, Fan7; Gabriel, Stephen8; Sandberg, Ingmar9; Glover, Alexi10; Hilgers, Alain3
    1Belgian Institute for Space Aeronomy, BELGIUM;
    2DH Consultancy, BELGIUM;
    4Departament d'Astronomia i Meteorologia & Institut de Ciències del Cosmos, Universitat de Barcelona, SPAIN;
    5KU Leuven/Centrum voor mathematische Plasma-Astrofysica, BELGIUM;
    6Kallisto Consultancy, UNITED KINGDOM;
    7RadMod Research, UNITED KINGDOM;
    8University of Southampton, UNITED KINGDOM;
    9Institute for Accelerating Systems and Applications & Department of Physics, University of Athens, GREECE;
    10ESA SSA Programme Office & Rhea System, ESA/ESAC, SPAIN

    Solar energetic particle (SEP) events are a serious radiation hazard for spacecraft as well as a severe health risk to humans travelling in space. Indeed, accurate modeling of the SEP environment constitutes a priority requirement for astrophysics missions and human exploration. ESA's Solar Energetic Particle Environment Modelling (SEPEM) application server is a WWW interface to SEP data and a range of modelling tools and functionalities intended to support space mission design. New SEP engineering models and tools to address current and future needs have been implemented by incorporating recent scientific results and a complete set of cross-calibrated data. SEPEM moves beyond mission integrated fluence statistics to peak flux statistics and durations of high flux periods. SEPEM has also integrated effects tools to allow calculation of single event upset rate and radiation background for a variety of engineering scenarios. Both statistical and physical modelling techniques have been addressed, covering not only 1 AU but also SEP environments ranging from 0.2 AU to 1.6 AU using a newly developed physics-based shock-and-particle model to simulate particle flux profiles of gradual SEP events. Away from 1 AU modelling is now available on the updated version of the SEPEM application server and provides the user community with a unique new tool. In the update all users now have access to the effects tools and can apply them to the SEPEM reference proton dataset that has been extended by four years and now ranges from 1973 to 2013. Furthermore, new data cleaning tools (de-spiking, median filtering) are available for the user to use on the available datasets.

    15   The PERICLES Long Term Data Preservation Project: Application to a Solar Database for Space Weather Applications.
    Muller, Christian1; PERICLES consortium, a2; ISS-SOLAR team, b3

    B.USOC manages several space experiments on the ISS and other platforms at the benefit of the science investigators who have proposed these instruments. One of these projects is the SOLAR package, monitoring the solar spectrum since February 2008. The operations of SOLAR, normally foreseen for less than two years, have been extended and are now planned to last until 2017. B.USOC has a mandate to preserve the data and distribute it to the Principal Investigators who then derive scientific products which are published and archived in science database. SOLAR is used as a case study for the ICT FP7 project PERICLES ( PERICLES aims to ensure that digital content remains accessible in an environment that is subject to continual change. This can encompass not only technological change, but also changes in semantics, academic or professional practice. PERICLES will take a 'preservation by design' approach that involves modelling, capturing and maintaining detailed and complex information about digital content, the evolving environment in which it exists, and the processes and policies to which it is subject. PERICLES represents a way for B.USOC of not only preserving the data and documentation of SOLAR but to transform this collection into a living archive. It is planned to include the products derived by the scientists and the related metadata generated by the science teams. In a further stage, in relation with the evolution of the mission duration itself and changes in operation procedures (for example since 2012, SOLAR measures full solar rotations near the solstices), the science teams can envisage higher level products and develop them from the newly reorganised archive. The relation of these new products and space weather applications will be presented. This talk discusses the current state of PERICLES (started in February 2013) and the tools which are under development to achieve these objectives.

    16   Improving User Experience with the new SPENVIS-NG Human Machine Interface
    Esther, Parrilla-Endrino1; Angela, Rivera1; Noelia, Sanchez1; Daniel, Heynderickx2; Michel, Kruglanski3
    1Deimos Space S.L.U, SPAIN;
    2DHConsultancy, BELGIUM;

    In this paper we present the new Human Machine Interface developed by DEIMOS in the context of SPENVIS-NG. The key objective of this ESA project (ESTEC Contract number: 4000104812) is the upgrading of the current SPENVIS system into a new web-based service-oriented distributed framework supporting plug-in of models related to the hazardous Space Environment. We introduce the brand new HMI that will be implemented using the latest state-of-the art technologies; the new solution will increase the reliability, security and stability of the current SPENVIS-4 HMI which has become old-fashioned. Also the system will be modular and flexible enough to support an advanced interface for user and contents management, the addition of new features such as new data analysis, workflow editor and visualization improvements, compliant with the proposed architecture. These capabilities will be easy enough to be used by a non-software skills person.

    17 Linking HERSCHEL SEUs to local Space Environment Conditions
    Kidger, Mark ; Glover, A.
    ESA, (SPAIN)

    The current sunspot cycle has so far been the smallest since early in the 20 th Century. In addition, during the extended minimum period between the peak of Cycle 23 and the start of Cycle 24 (2006-2010), cosmic ray fluxes were measured by both space and ground based observatories to be unusually high. The Herschel mission was operational during the solar minimum period and rise phase of Cycle 24 between 2009 and 2013. The four year record of the cosmic ray flux from Herschel's SREM shows a drop of a factor 2 in the proton flux between 10 and 166MeV between the end of 2009 and the end of mission. As no enhancement of SEUs is seen during SPEs it is assumed that the energetic particle flux (energies >>160MeV) is the cause of Single Event Upsets (SEUs), bit-flips in the on-board memory that affects instruments and the satellite mass memory. While there is evidence that the rate of SEUs in Herschel's SPIRE and HIFI instruments were lower around the time of peak solar activity in 2011, a study of bit-flips in Herschel's mass memory finds that although there was a significantly higher rate of bit flips in the first 6 months of the Herschel mission, the rate of bit flips was constant to a high degree from then on. Furthermore, no variations in the rate of bit flips in mass memory exist above the errors between the start of 2010 and the end of mission.

    18 Some aspects of the impact of the radiation environment at L2 on the operations of Planck
    Mendes, L.
    ESA, (SPAIN)

    I use data acquired by the Standard Radiation Environment Monitor on board the Planck satellite to analyse the impact of the radiation environment at L2 on the operations and data acquisition of Planck. I will summarise the most important radiation events observed during the lifetime of the Planck mission and will illustrate their impact on the thermal stability of the instruments on board Planck.