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|Chapter|19 |
|ESA Space Weather Activities |
|Eamonn J. Daly |
|Space Environments and Effects Analysis Section, |
|European Space Agency, ESTEC 2200 AG |
|Noordwijk,The Netherlands |


Abstract The European Space Agency (ESA) is undertaking a space weather
initiative in which preparatory studies are being performed and
developments are being made to pave the way for a possible future
ESA space weather programme and a possible European space weather
service. This initiative is based on long-standing activities in
analysis of space environments and their effects on European space
programmes and on a successful solar terrestrial physics programme
over many years and many missions. This chapter describes these
activities, discusses space weather effects, outlines the goals of
the present phase of ESA's initiative and discusses future
directions.

Keywords ESA, space weather, space environments and effects.

1. Introduction

THE NATURAL SPACE ENVIRONMENT REPRESENTS A CONSIDERABLE HAZARD FOR
SPACECRAFT AND THE EUROPEAN SPACE AGENCY (ESA) HAS FOR MANY YEARS TAKEN
MEASURES TO ENSURE THAT ITS SPACECRAFT ARE ABLE TO SURVIVE AND OPERATE IN
IT. AS SPACECRAFT AND THEIR PAYLOADS HAVE BECOME MORE SOPHISTICATED, SO
THEIR SUSCEPTIBILITIES TO EFFECTS INDUCED BY THE ENVIRONMENT HAVE
INCREASED. CONSEQUENTLY ESA HAS, LIKE OTHER ORGANIZATIONS, INCREASED ITS
EFFORTS IN ANALYSING THESE PROBLEMS AND IN DEVELOPING THE MEANS TO
UNDERSTAND AND ANTICIPATE THE ENVIRONMENT AND TO AVOID THE EFFECTS. THIS
ENVIRONMENT AND ITS COMPLEX BEHAVIOR ARE ALSO SUBJECTS OF INTENSIVE
SCIENTIFIC INVESTIGATION WITHIN SOLAR-TERRESTRIAL PHYSICS. SPACE WEATHER
ENCOMPASSES A BROAD RANGE OF PHENOMENA (SOLAR, INTERPLANETARY, GEOMAGNETIC,
IONOSPHERIC, ATMOSPHERIC AND SOLID EARTH) IMPACTING SPACE AND TERRESTRIAL
TECHNOLOGIES. IT IS A SUBJECT WHICH IS OF RELEVANCE TO DEVELOPERS OF
TECHNOLOGICAL SYSTEMS BUT ONE WHICH RELIES ON CHARACTERIZATION AND
UNDERSTANDING OF THE SOLAR-TERRESTRIAL SYSTEM.
A few high-profile space weather events have drawn attention to the
effects. For example, the hazards to spacecraft from electrostatic charging
(Baker et al, 1996, Fredrickson, 1996, Wrenn, 1995) and to ground-based
power networks from induced current surges (Kappenman and Albertson, 1990,
Lanzerotti, 1979). But these are just the "tip of the iceberg" of more
numerous, less well-publicized problems and implications. There is
consequently a growing appreciation that as society becomes more reliant on
space-based systems for services such as communications and navigation, the
disruptions to these services from space weather has become a serious
issue. Apart from disruption to commercial space activities, scientific
missions can be seriously affected because of their use of highly advanced
technologies. Recent examples which will be further discussed are the
effects on the Chandra and XMM (X-Ray Multi-Mirror) Newton X-ray
astrophysics missions. The analyses of potential problems on these
missions, and continuing evaluation in-flight, are good examples of the
needs for accessible space weather resources including databases,
"predictive" models and near-real-time data. Furthermore, over the next few
years manned spaceflight will undergo a considerable expansion with the
exploitation of the international space station. Space weather, in the form
of enhancements to energetic particle radiation, is of crucial importance
for manned space activities. Space radiation also penetrates the upper
atmosphere where crew and electronic systems on aircraft can be affected.
Finally, ground-based systems such as power distribution networks,
pipelines and ground-to-ground radio communications can also be seriously
affected.
At the time of writing, we are near the maximum of the current cycle,
cycle 23. The increased chances of solar flares, coronal mass ejections and
solar energetic particle events have led to added interest in space weather
both from the space community and from the general public. This interest is
supported by an array of excellent solar-terrestrial science missions such
as the joint ESA-NASA Solar and Heliospheric Observatory SOHO (Huber and
Wilson, 2000). However, it is important to recognize that the effects of
Space Weather are present throughout the solar cycle and that some
important aspects can be more severe away from solar maximum. For example
electron flux levels in the Earth's outer radiation belt are generally
higher during the decaying phase of the solar cycle.
The space weather discipline draws from both the space environments and
effects domain and from the solar-terrestrial physics domain. ESA and
European research agencies have strengths in both areas. There is
considerable interest in Europe to investigate the marriage of the
technological and scientific capabilities to address perceived user needs
for space weather products and services. Whereas co-ordinated Space Weather
activities are well established in the US, Europe has yet to undertake a co-
ordinated program in this area. Past ESA workshops and studies identified
the needs as well as possible European approaches to the subject (ESA,
1998, Koskinen et al., 1999). An important step towards a co-ordinated
European Space Weather program has recently been taken with the initiation
of broadly based studies in the context of the ESA General Studies
Programme. Major parallel studies are laying the groundwork for a possible
operational European space weather service. These studies will be discussed
further later in this chapter.

2. Space Weather Problems for ESA Programmes


2.1 GENERAL

During the development of spacecraft, the expected environment needs to be
carefully considered. The development process includes analyses of possible
problems from the space environment and the implementation of appropriate
measures to avoid or cope with effects of concern. Analyses make use of
information on the environment in the form of models and tools which have
developed over the years to cope with an evolving set of problems. Some of
the effects on space systems are summarized in Table 1.
In this section, the major environmental effects will be outlined and
their connection with space weather described.

2.2 Radiation Effects

As in other space agencies, ESA's concerns with space weather effects
probably began with concerns over radiation effects on spacecraft systems.
This radiation environment is due to sporadic solar particle events,
energetic protons and electrons trapped in radiation belts and cosmic rays
(e.g. Daly, 1989). The effects of these in damaging solar cells, electronic
components and inducing upsets in large-scale-integrated electronics had
long been taken into account in spacecraft development. In the last decade
there has been a general increase in radiation-related problems and new
types of problems have arisen.
While the preoccupation in the 1960's and 1970's was very much with the
damage caused over the lifetime of a spacecraft to solar cells and
components, in later years a number of other effects have arisen. The
changes in states of logic elements in integrated circuit induced by the
charge trail left by passage of a single energetic ion, known as single
event upsets (SEU), have become a major concern since effects on the
spacecraft controlling functions could have devastating consequences.
Single event rates can often be coped with when they occur in non-critical
memories such as data stores and can often be corrected by special
circuitry. Dramatic increases in the SEU rates often occur during solar
energetic particle events as shown in Figure 1 from the SOHO mass memory
unit. The rate rose by a factor of 6 at the peak of the November 1997 event
and by a factor of 300 at the peak of the July 2000 event.


|Environment |Effects |
|High Energy Radiation: | |
|Cosmic Rays |Upsets in electronics; |
| |Long-term hazards to crew;|
| | |
| |Interference with sensors;|
|Solar Energetic Particle |Radiation damage of |
|Events |various kinds; |
| |Upsets in electronics; |
| |Serious prompt hazards to |
| |crew; |
| |Massive interference with |
| |sensors; |
|Radiation Belts |Radiation damage of |
| |various kinds; |
| |Upsets in space |
| |electronics; |
| |Hazards to astronauts; |
| |Considerable interference |
| |with sensors; |
| |Electrostatic charging and|
| |discharges |
|Near-Earth Plasma | |
|Populations: | |
|Geomagnetic (sub-) storms |Electrostatic charging and|
| |discharges; |
|Ionospheric Effects |Communications disruption;|
| | |
| |Navigation services |
| |disruption |
|Others: | |
|Atmosphere |Increased drag on |
| |spacecraft and debris; |
| |Attitude perturbation |
|Meteoroids |Spacecraft damage |


Table 1. The various space-weather environments and their effects.

Another source of interference is radiation background. Imaging detectors
such as, charge-coupled devices (CCD's) are used in a variety of space
applications including as imaging elements in space telescopes, in Earth
observation systems or in star trackers of attitude control systems.
Particles impacting a detector can give rise to signals which appear as
"noise" on the image, sometimes completely overwhelming the image. Examples
from the ESA-NASA SOHO spacecraft are shown in Figure 2. These images were
taken during the July 2000 solar proton event and show heavy contamination
of the image from particle hits on the detector. Such contamination is a
feature of many space-borne detectors.


[pic]

Figure 1. SOHO mass-memory single-event upsets. The spikes in November 1997
and July 2000 are due to solar particle events

ESA's Infrared Space Observatory and Hipparcos spacecraft also
experienced background effects and it is also a feature of the XMM-Newton
detectors. In many cases it can be removed with image processing software
but if heavy contamination is present during space weather events, the data
are lost. It is becoming more common to use star trackers as part of the
attitude control systems of spacecraft. These help orient the spacecraft by
recognizing sets of star patterns. If the image contains a lot of bright
features induced by radiation, the system can become confused and several
examples are known where this has occurred and led to loss of attitude.
Clearly, the image background during solar energetic particle events will
be very much higher than normal.

2.3 Electrostatic Surface and Internal Charging

The importance of space weather to space systems increased in the 1980's
as a result of several cases of operational anomalies on geostationary
communications and meteorology spacecraft. The anomalies were attributed to
high-level electrostatic charging of surfaces which led to discharges and
electromagnetic-induced disruption of spacecraft systems. The charging
events were associated with surges of hot plasma flowing into the parts of
the magnetosphere around the geostationary altitude (about 36000km) during
geomagnetic "sub-storms". The affected missions include the Marecs marine
communications test satellites, the ECS series of communications test
satellites and the pre-operational satellites in the Meteosat
meteorological satellite series. In investigating the Meteosat-1 anomalies,
a decision was taken to put a plasma environment monitor on the second
spacecraft in the series. The analyses of these data and their correlations
with anomalies led to the conclusion that the anomalies were not due to
high level surface charging.

[pic]

Figure 2. Images taken by the LASCO (left) and EIT (right) telescopes on
the joint ESA-NASA SOHO mission during the July 2000 solar energetic
particle event showing severe effects on the detector from radiation
background.

About this time, it was noted by Baker et al. (1987) that anomalies on US
spacecraft correlated with energetic (~MeV) electrons, implying that
penetrating electrons could induce charging and discharging within
spacecraft by collecting in dielectric materials or ungrounded metallic
parts. Since it was a likely source of the Meteosat anomalies, Meteosat-3
contained a detector to monitor these higher energy electrons. The data
showed very clear correlations with anomalies (Rodgers et al., 1998).
Figure 3 shows a superposed epoch analysis of the >2MeV electron fluxes,
measured in this case by a detector on the GOES geostationary satellite,
for all anomalies of a particular type. This shows the average environment
preceding the anomalies. The clear increase in energetic electron flux is
highly indicative of internal charging as a source. Similar behavior was
also reported by Wrenn (1995) for a classified UK defense satellite during
the 1990's. Furthermore the energetic electron flux before the failures of
the primary and back-up processors on the Equator-S mission strongly
suggest that internal charging led to this total satellite loss. The
environment measured by a detector on GOES-8 is shown in Figure 4 where it
can be seen that preceding the failures the energetic electron fluxes were
high as a result of injection events ("storms"). Equator-S was in an
eccentric equatorial orbit crossing the radiation belts while GOES is in
geostationary orbit. Equator-S was therefore probably exposed to a more
severe environment than GOES measured. These European examples are in
addition to several cases reported in recent years in the US.

[pic]

Figure 3. The average >2MeV electron environment preceding a particular
type of anomaly on Meteosat-4. On average, the flux of energetic electrons
increases by orders of magnitude before an anomaly


2.4 The Role of Models

To ensure that spacecraft will operate correctly in the presence of these
effects, it is necessary during the development process to use models of
the environments and effects for analyses, and to undertake appropriate
testing. Models are intended to address the needs of the space system
developer and for efficiency and usability reasons often simplify the
physics involved in the phenomena. Even when physical understanding or
information is incomplete, the threat still needs to be countered with some
quantitative method, albeit of limited validity. It is nevertheless a long-
term objective for this community to have models available which are both
physically accurate and responsive to the users needs. A good example is in
the area of radiation environments and effects where for many years
developers have used the "standard" AP-8 (Sawyer and Vette, 1976) and AE-8
(Vette, 1991) models of the radiation belts. These models are known to be
weak and do not represent the dynamic ("space weather") behavior of the
electron belt. Nevertheless, in the absence of anything better, they have
continued to be used. Developments have recently given hope but there still
remains a usability problem.

[pic]

Figure 4. The environment in geostationary orbit as measured by GOES-8
detectors for the periods around the Equator-S primary and backup processor
failures, indicated by the arrows

ESA's Space Environments and Effects Analysis Section has responsibility
for supporting the development of ESA missions. The service it provides
includes assessments of elements in Table 1. In parallel with this support
function, it is responsible for the initiation and execution of technology
R&D as part of a space environments and effects technical domain of ESA's
Technology Research Programme (ESA, 1999). This R&D has led to developments
of tools and models, as well as R&D for longer-term application. In doing
this R&D and support work, the section is closely in touch with the user
needs for space weather data for space system applications. Current R&D
activities include (ESA, 1999):

- The Space Environment Information System (Spenvis) (Heynderickx, 1998).
This is an internet/intranet-based system containing a wide range of
models, tools and data concerning many aspects of space environments and
their effects on space systems. It is targeted at the space systems
developer who needs rapid reliable access to authoritative (often
standard) methods. The system also contains link to the European ECSS
engineering standard on space environment (ECSS, 2000).
- Modelling of the Earth's radiation belts where various high altitude and
low-altitude data sets are studied to validate or improve models of the
radiation belts. The activity also includes detailed comparison between a
physical model, SalammbÒ, and spacecraft data of energetic electron belt
dynamics
- Development of data-based analysis of space environments ("SEDAT") (CLRC,
2000) where existing spacecraft data sets are interrogated by standard
and user-defined methods to derive custom "models".
- Development of engineering tools for assessment of the hazard from
charging of materials inside spacecraft by energetic electrons ("internal
charging") (SÜrensen et al., 1999). This research also investigated the
way to specify the hazard for design and the associated test methods.
- Participation with the high-energy physics community in a world-wide
effort to produce a next generation of object-oriented tool-kit for
simulations of particle interactions with matter ("Monte-Carlo codes"),
Geant4 (Apostolakis, 2000). This effort was initiated by CERN, the
European center for nuclear research. ESA's activity has resulted in
space-specific features for Geant4 (Truscott et al., 2000).
- Developments of space environment monitors and the analysis and
exploitation of data from them (BÝhler, 1998, Desorgher at al., 1999,
Daly et al., 1999).
- Analysis of electrostatic charging behavior of spacecraft in polar orbits
and analyses of the correlations between anomalies and environmental
parameters (Andersson et al., 1998). These studies also included research
on tools for anomaly predictions (Wu et al., 1998).
- Research on AI methods in spacecraft anomaly analysis and prediction -
the SAAPS (Spacecraft Anomaly Spacecraft Anomaly Analysis and Prediction
System) (Wintoft, 1999).

Many other important activities have been undertaken including activities
related to Martian environments, micro-particle impacts and contamination
(ESA, 1999).

3. Space Weather and Space Environment Support to Project Development

AS MENTIONED, A KEY TASK IS TO SUPPORT SPACE SYSTEMS DEVELOPMENT.
VIRTUALLY ALL ESA SPACECRAFT ARE SUPPORTED, STARTING EARLY IN THE PROCESS
WITH THE MISSION CONCEPT DEFINITION. A GOOD CASE HISTORY IS THE XMM-NEWTON
X-RAY ASTRONOMY MISSION.
X-ray astronomy in space relies on the focussing of X-ray photons by low-
angle scattering from shaped "shells". In most cases the "optics" consist
of two sets of nested concentric shells with shapes near to sections of
cones. Two grazing-incidence scatters result in focussing of the X-rays on
the shell axis. ESA's XMM-Newton mission has three mirror modules of outer
diameter 70 cm, each consisting of 58 nested shells which focus the X-rays
onto CCD detectors some 7 m from the mirrors. XMM is in a highly eccentric
orbit of apogee 114000km, perigee 7000km and inclination 39(. In this orbit
it is subjected to fluxes of electrons and ions of various energies from
magnetospheric and heliospheric sources.
Recently, an intensive investigation was undertaken to study potential
problems to detector operation from medium-energy (100's of keV's) protons
(Nartallo et al., 2000). CCD detectors are known to be radiation sensitive
and much attention is given to shielding them against radiation penetrating
spacecraft structural materials. However, it was found that protons of
energies in the range of hundreds of keV to a few MeV could scatter at low
angles through the mirror shells. These protons, because of their low
energy can produce a high non-ionizing dose in unshielded CCDs and
therefore pose a potential threat. Historical data on the interplanetary
and magnetospheric low-energy proton environments were interrogated to
determine the magnitude of the threat. Complex modelling of particle
propagation through spacecraft systems was undertaken with the Geant4 Monte-
Carlo toolkit. The datasets were used to establish details of observing
time expected to be lost in protecting the CCDs from sporadic particle flux
enhancements by closing protective shields. Several interesting points
regarding space weather can be made as a result of this analysis:

- Crucial data sets used for the analysis of mission-critical engineering
problems were produced by science missions (IMP, SOHO, ACE, Equator-S,
ISEE) which could never foresee such applications;
- XMM-Newton has an on-board radiation monitor, to which there was
resistance early in the project preparation. It is now an important
resource on the spacecraft;
- Spacecraft operators are keenly interested in the state of the space
weather and would certainly make use of predictions of sporadic particle
enhancements should they be available.

All this effort was in addition to several space environment related
analyses carried out in the course of the definition and development of the
XMM-Newton mission over the preceding 10 years. In such a process, early
analyses of the environments of orbit options were undertaken, followed by
detailed analyses related to the final orbit and the radiation doses and
particle fluxes to be anticipated for electronic components and detectors.
Further analyses included assessments of the electrostatic charging
hazards, analysis of the potential problems from micro-meteoroids
(punctures to telescope tube and hazards to fuel tanks) and detailed
analysis of radiation background sources (Dyer et al., 1995, Hilgers et
al., 1998). XMM-Newton was launched in December 1999 and is operating well.

4. ESA's Science Activities

ESA'S SCIENCE PROGRAM IS RELATED TO SPACE WEATHER IN TWO WAYS. SPACE
WEATHER EFFECTS ON SCIENCE MISSIONS ARE AN INCREASING CONCERN, WHILE ON THE
OTHER HAND SCIENCE MISSIONS CAN CONTRIBUTE CRUCIALLY TO SPACE WEATHER
RESEARCH. AS SPACE SCIENCE MISSIONS BECOME MORE COMPLEX AND DEMANDING, THE
NEED TO DESIGN TOLERANCE TO SPACE WEATHER EFFECTS INTO SCIENTIFIC PAYLOADS
AS WELL AS SPACECRAFT SYSTEMS BECOMES MORE IMPORTANT. EXAMPLES INCLUDE
SENSITIVITY TO RADIATION, LEADING TO INCREASED BACKGROUNDS AND EVEN
DETECTOR DAMAGE, AS WELL AS THE COMPLETE FAILURE OF KEY COMPONENTS. AS
MENTIONED ABOVE, THESE ISSUES WERE OF CONCERN TO THE RECENTLY LAUNCHED XMM-
NEWTON MISSION (NARTALLO ET AL., 2000).
An important spin-off of scientific missions can be to show what is
possible for future service-oriented ventures. For example, the joint ESA-
NASA SOHO mission is a key member of the fleet of spacecraft studying the
Sun and its effects on the interplanetary environment. It is also highly
useful as a resource for providing Space Weather warnings. ESA's scientific
studies related to Space Weather phenomena were further enhanced with the
launch of the Cluster II satellites.
As part of the competitive process for selection of future science
missions, ESA recently studied future medium-sized missions. Among these
were the STORMS and Solar Orbiter proposals, both of which could contribute
to the world-wide space weather effort. STORMS was proposed as a set of 3
spacecraft in eccentric near-equatorial earth orbits. With apogee at about
8 Earth radii, the spacecraft pass through the radiation belts and the ring
current regions. As the name suggests, the principal motivation for the
mission was to study the physics of geomagnetic storms and the inner
magnetosphere's responses to them. The spacecraft would carry particle and
fields instruments and energetic neutral atom imagers. Solar Orbiter was
proposed to orbit the sun as close as 40 solar radii (0.19 AU) and to carry
out detailed solar remote sensing. Its orbit would also take it to helio-
latitudes of about 33º. For part of the time the orbit would be quasi-co-
rotational. Spectroscopy and imaging would be performed at high spatial and
temporal resolution, along with in-situ sampling of particles and fields.
Both proposals were highly rated and eventually Solar Orbiter selected for
implementation. Launch is presently planned for 2009.

5. Efforts Towards a European Space Weather Programme

RECOGNIZING THAT THERE IS A GROWING NEED FOR SPACE WEATHER RELATED DATA FOR
ESA PROGRAMS, AND ALSO THAT THERE WERE ISSUES RELATED TO THE IMPACT OF
SPACE WEATHER ON NON-SPACE TECHNOLOGIES WHICH COULD BE IMPORTANT FOR
EUROPE, ESA TOOK STEPS TO ANALYZE THE SUBJECT IN DETAIL. WHILE NOT THE
FIRST ESA ACTIVITY, A WORKSHOP HELD IN 1998 (ESA, 1998) WAS AN IMPORTANT
EVENT WHICH BROUGHT TOGETHER THE USER, SCIENCE AND TECHNOLOGY COMMUNITIES
TO EXPLORE THE POSSIBLE WAYS FORWARD. IT WAS CLEAR THAT USER NEEDS WERE
GROWING. AT THE SAME TIME, THE MATURITY ACHIEVED IN SOLAR TERRESTRIAL
PHYSICS, ALLIED TO TECHNOLOGICAL ADVANCES (IN-ORBIT MONITORING, GROUND-
BASED COMPUTING POWER, ETC.) MEANT THAT IT WAS CERTAINLY FEASIBLE TO
DELIVER PRODUCTS FOR USERS IN THE SHORT TERM AND CONTEMPLATE CONSIDERABLE
IMPROVEMENTS TO THEM OVER THE MEDIUM AND LONG TERMS. THESE IMPROVEMENTS
WOULD IMPLY DEVELOPMENTS IN THE SYSTEMS DEPLOYED IN SPACE AND ON THE GROUND
FOR SPACE WEATHER MONITORING AND IN THE SCIENCE, SIMULATION, MODELLING AND
DELIVERY ASPECTS OF THE GROUND-BASED ACTIVITIES. AS A RESULT ESA APPROVED
THE EXECUTION OF PARALLEL WIDE-RANGING STUDIES. THE TWO STUDIES (ESA, 2000)
ARE LED BY ALCATEL SPACE AND RUTHERFORD APPLETON LABORATORY. IN EACH
CONSORTIUM THERE IS A STRONG BLEND OF TECHNOLOGY, SCIENCE AND APPLICATIONS.
THE TOP-LEVEL GOALS OF THE STUDIES ARE TO:

- investigate the needs for and the benefits of an ESA or other European
space weather program
- establish the detailed data supply requirements by detailed consideration
of the quantification of effects and intermediate tools;
- perform detailed analysis of potential program contents:
a detailed definition of the space-segment
a detailed definition and proto-typing of the service-segment
- perform an analysis of collaborative and organizational structures which
need to be implemented by ESA and member states
- provide inputs and advice for preparation of a program proposal,
including project implementation plan, cost estimate and risk analysis.

In association with these activities, ESA has also established a Space
Weather Working Team consisting of European experts in various space
weather and user domains, to oversee the activities and advise ESA on
future activities.
While there is considerable interest in space weather in Europe,
initiating any major new ESA space weather activity requires the agreement
of national delegations to ESA's decision-making committees. Such a
commitment can only be made after the needs for such expansion and the
demonstration of its benefits are clearly established. The more scientific
aspects will probably be the responsibility of ESA's science program where
proposals are subject to the well-established peer review selection
process. While technological research and developments will continue into
space environments and effects, any large expansion of these activities for
ground- and space-based space weather infrastructures is conditional upon
high-level approval. The above studies and associated activities are
crucial in establishing the justification.
In ESA member states many important activities related to space weather
are being undertaken as part of national programs (ESA, 1998). These
include activities addressing military needs. The interests of ESA's
various member-states also differ. For example, Scandinavian and other
nations at high latitude are keenly interested in effects on power systems,
pipelines and other ground systems from auroral electrojet induced ground-
level currents.
It will also be important to consider how any eventual service will be
implemented in Europe. ESA's role is as an initiator and developer of
technologies. The provision of fully operational end-user services should
be provided by other organization in a way analogous to satellite
communications or meteorology.

6. Conclusions

THE WIDE-RANGING ACTIVITIES OF ESA IN THE SPACE WEATHER AND SPACE
ENVIRONMENT DOMAINS HAVE BEEN SUMMARIZED AND RECENT IMPORTANT EXAMPLES OF
SPACE WEATHER CONCERNS GIVEN. IN PARTICULAR, THE SPACE WEATHER EFFECTS ON
XMM AND EFFORTS TO ANALYZE THESE EFFECTS AND OTHER SPACE ENVIRONMENTAL
HAZARDS ILLUSTRATED THE DEPTH AND BREADTH OF THE WORK THAT IS TYPICALLY
NECESSARY IN THIS DOMAIN WHEN PREPARING A COMPLEX SPACE MISSION.
We have highlighted the important scientific and technological
contributions that ESA in particular and Europe in general have made. We
emphasize that while there is considerable interest in Europe in expanding
space weather activities toward a fully-fledged program, this will be as a
result of clear demonstration of real needs and benefits. These complex
issues are being addressed by on-going studies.

7. Acknowledgements

I AM VERY GRATEFUL TO ALAIN HILGERS OF ESA/ESTEC FOR HIS CONSIDERABLE
EFFORTS RELATED TO THE ESA SPACE WEATHER INITIATIVES DESCRIBED HERE. THE
DATA USED IN FIGURE 1 WERE PROVIDED COURTESY OF HELMUT SCHWEITZER OF THE
SOHO PROJECT TEAM. THE IMAGES ON FIGURE 2 ARE COURTESY OF THE SOHO/LASCO
AND SOHO/EIT CONSORTIA OF THE MISSION. SOHO IS A PROJECT OF INTERNATIONAL
CO-OPERATION BETWEEN ESA AND NASA. THE DATA USED IN FIGURE 4 WERE OBTAINED
FROM THE NOAA-NGDC SPIDR SERVICE.

8. References

ANDERSSON L., L. ELIASSON, P. WINTOFT, PREDICTION OF TIMES WITH INCREASED
RISK OF INTERNAL CHARGING ON SPACECRAFT, IN PROCEEDINGS OF THE ESA
WORKSHOP ON SPACE WEATHER" ESA-WPP-155, NOVEMBER 1998.
Apostolakis J., Geant4 status and results, CHEP-2000 Conference, to appear
in proceedings, 2000
Baker, D. N., J. H. Allen, R. D. Belian, J. B. Blake, S. G. Kanekal, B.
Klecker, R. P. Lepping, X. Li, R. A. Mewaldt, K. Ogilvie, T. Onsager, G.D.
Reeves, G. Rostoker, H.J. Singer, H. E. Spence, N. Turner, An assessment
of space environmental conditions during the recent Anik E1 spacecraft
operational failure", ISTP Newsletter, Vol. 6, No. 2. June, 1996.
Retrievable from http://www-istp.gsfc.nasa.gov/istp/newsletter.html
BÝhler P., Desorgher L., Zehnder A. and Daly, E., Observation of the
Radiation-Belts with REM, in: Proceedings of the ESA Workshop on Space
Weather, WPP-155, p.333, ESA, 1998.
CLRC Rutherford Appleton Laboratory, SEDAT Project homepage
http://www.wdc.rl.ac.uk/sedat/, 2000
Daly E.J., Radiation Environment Evaluation for ESA Projects, in High
Energy Radiation Background in Space, eds. A.C Rester & J.I. Trombka AIP
Conference Proceedings 186, NewYork 1989 483-499
Daly E.J., P. BÝhler and M. Kruglanski, Observations of the outer radiation
belt with REM and comparisons with models, IEEE Trans. Nucl. Sci NS-46, 6,
December 1999.
Desorgher L, P BÝhler, A Zehnder, E. Daly and L Adams, Modelling of the
outer electron belt during magnetic storms, Radiation Measurements 30, 5
pp 559-567, 1999
Dyer C. and Truscott P., The analysis of XMM instrument background induced
by the radiation environment in the XMM orbit", DERA report
DRA/CIS(CIS2)/CR95032/1.0, final report on work performed for ESTEC
Contract No 10932/94/NL/RE, December 1995;
http://www.estec.esa.nl/wmwww/WMA/XMM/XMM.html
ECSS (European Co-operation on Space Standards), Space Environment, ed. E.
Daly, ECSS-E-10-04, ECSS Secretariat, ESTEC, Noordwijk The Netherlands,
2000.
ESA, Proceedings of the Workshop On Space Weather, ESTEC, Noordwijk, The
Netherlands, ESA WP-155, 1998
ESA, Space environments and effects, in: Special Issue, Preparing for the
Future Vol. 9, No. 3, December 1999.
ESA Space Weather Studies www Site:
http://www.estec.esa.nl/wmwww/spweather/spweathstudies.htm , ESA, 2000.
Fredrickson A.R., Upsets related to spacecraft charging, IEEE Trans. Nucl.
Sci. NS-43, 2, 426, 1996.
Heynderickx, D., Quaghebeur, B., Fontaine, B., Glover, A., Carey, W.C. &
Daly, E.J., New features of ESA's space environment information system
(Spenvis), in: Proc. ESA Workshop on Space Weather, ESTEC, Noordwijk, The
Netherlands, ESA WPP-155, pp. 245-248, ESA 1998.
Hilgers A., P. Gondoin, P. Nieminen and H. Evans, Prediction of plasma
sheet electron effects on X-ray mirror missions, Proc. ESA Workshop On
Space Weather, ESTEC, Noordwijk, The Netherlands, ESA WP-155 p.293, 1998.
Huber M.C.E. and Wilson A., eds., ESA's report to the 33rd COSPAR meeting",
pp.29-33, ESA- SP-1241, 2000.
Kappenman J.G. and Albertson V.D., Bracing for the geomagnetic storms",
IEEE Spectrum, , p5, March 1990.
Lanzerotti, L. J., Geomagnetic influences on man-made systems, J. Atm.
Terr. Phys., 41, 787-796, 1979.
Nartallo R., E. Daly, H.D. Evans, A. Hilgers, P. Nieminen, J. SÜrensen, F.
Lei, P.R. Truscott, S. Giani, J. Apostolakis, L. Urban and S. Magni,
Modelling the Interaction of the Radiation Environment with the XMM-Newton
and Chandra X-ray Telescopes and its Effects on the On-board CCD
detectors, Proceedings of the Space Radiation Environment Workshop, DERA
Space Department, Farnborough, UK, in Press 2000.
Sawyer D.M. and Vette J.I., AP8 trapped proton environment for solar
maximum and solar minimum', NSSDC 76-06, 1976.
SÜrensen J., D. J. Rodgers, K. A. Ryden, P.M. Latham, G. L. Wrenn, L. Levy,
G. Panabiere, ESA's tools for internal charging., in: Proceedings of the
Conference on Radiation and its Effects on Components and Systems
(RADECS), 1999.
Truscott P., F. Lei, C. Ferguson, R. Gurriaran, P. Nieminen, E. Daly, J.
Apostolakis, S. Giani, M.G. Pia, L. Urban, M. Maire, Development of a
spacecraft radiation shielding and effects toolkit based on Geant4, CHEP-
2000 Proc., 2000.
Vette J.I. The AE-8 trapped electron model, NSSDC/WDC-A-R&S 91-24, 1991
Wintoft P., Development of AI methods in spacecraft anomaly predictions,
IRF Web site http://eos.irfl.lu.se/saaps/ 1998.
Wrenn G.L. Conclusive evidence for internal dielectric charging anomalies
on geosynchronous communications spacecraft, J. Spacecraft and Rockets 32,
pp 514-520, May-June 1995
Wu, J.G, Lundstedt, H., Eliasson, L., Hilgers, A., Analysis and real-time
prediction of environmentally induced spacecraft anomalies, in Proceedings
of the ESA Workshop on Space Weather ESA-WPP-155, November 1999.