Session - Spacecraft operations and space weather
Dave Pitchford and Richard Horne
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; emerging challenges due to
innovative technology and mission concepts.
Talks
Thursday November 20, 09:00-13:00, auditorium Reine Elisabeth
Poster Viewing
Thursday November 20, 10:15-11:30, area in front of auditorium Reine Elisabeth.
The numbering of the posters might differ from the numbering on the page with the short overview without abstracts.
Talks
1 |
Oral |
9:00 am |
Low Energy Electrons (< 200
keV) in the Inner Magnetosphere during Extreme Space Weather Events |
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Ganushkina, N |
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Finnish Meteorological Institute |
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The distribution of low energy
electrons, the seed population (10-150 keV), is critically important for
radiation belt dynamics. This seed population is further accelerated to MeV
energies by various processes. The electron flux at these energies is largely
determined by convective and inductive electric fields and varies
significantly with substorm activity driven by the solar wind. Presence of
low energy electrons in GEO (geostationary) and MEO (medium Earth orbit)
orbits mainly between midnight and dawn can cause surface charging, changes
in the satellite potential and degradation of satellite surface materials.
The injected electrons can also penetrate along the magnetic field lines to
low altitudes and affect polar orbiting satellites in LEO (low Earth orbit)
orbit at high latitudes. The model which is able to specify the electron flux
for all L shells and at all satellite orbits, when necessary, for a given
solar wind and IMF input is Inner Magnetosphere Particle Transport and
Acceleration model (IMPTAM). We present the results of modeling of low energy
electrons fluxes for several past extreme space weather events (with Dst <
-250 nT) comparing them to the observations on satellites at different
orbits. The periods include the years between 2000 and 2007 when POLAR, LANL,
GEOTAIL and CLUSTER data are available. The source, transport and loss
processes are reviewed with the emphasis to the extreme events. |
2 |
Oral - invited |
9:15 am |
New Charged Particle
Measurements and Products from GOES-R |
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Rodriguez, J1; Onsager, T2 |
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1University
of Colorado; 2NOAA
Space Weather Prediction Center |
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The NOAA Geostationary
Operational Environmental Satellite (GOES) program has provided continuous,
real-time measurements of the near-Earth space environment for decades. In
addition to their scientific value, the GOES energetic particle measurements
form the basis for a variety of space weather products and services,
including the forecasting of elevated energetic particle levels, real-time
knowledge of the satellite environment at geostationary orbit, and data to
allow post-event analyses when satellite anomalies occur. The GOES satellites
have traditionally provided measurements of high-energy electrons, protons,
and alpha particles (100s of keV to 100s of MeV). Beginning with the launch
of GOES-13 in 2006, the measurement capabilities were expanded to include
medium-energy electrons and protons (10s to 100s of keV) with pitch angle
resolution. The next generation of GOES satellites, starting with GOES-R in
2016, will fly four new particle instruments that will greatly expand the
energy and species coverage over GOES 13-15.
The low-energy Magnetospheric Particle Sensor (MPS-LO) will measure
electrons and ions from 30 eV to 30 keV.
The high-energy Magnetospheric Particle Sensor (MPS-HI) will measure
electrons and protons from 50 keV to several MeV. Pitch angles for MPS-LO and MPS-HI fluxes
will be derived from fluxgate magnetometer measurements on the same
satellite. A moments (density and temperature) and spacecraft charging
product will be derived from the MPS measurements. Solar and Galactic Proton Sensors (SGPS) on
each satellite will measure the spectra of 1-500 MeV protons and >500 MeV
integral flux in two directions. From
the SGPS channel fluxes, integral fluxes will be derived, which in turn will
support NOAA real-time alerts of solar proton events. Finally, the Energetic Heavy Ion Sensor
(EHIS) will be capable of resolving heavy ion species from beryllium to
nickel, as well as helium and hydrogen above 10 MeV/nucleon. The EHIS measurements will be used to
estimate flux spectra as a function of linear energy transfer (LET). |
3 |
Oral |
9:30 am |
Simulated Electron Flux at GEO
for the Carrington Event using the USSW Model |
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Boynton, R1; Balikhin, M1; Billings, S1 |
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1University
of Sheffield |
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The University of Sheffield's
SNB^3GEO electron flux model has been operating online since 2012, providing
a reliable forecasts with a high prediction efficiency of the next days
>800 keV and >2 MeV electron flux. The exemplary forecasting capability
of SNB^3GEO have been exploited to estimate evolution of electron flux during
Carrington event, the super magnetic storm that took place between 28 August
and 4 September 1859. The Carrington event is the most powerful and famous
space weather event on record and if such a storm were to take place today,
it would cause havoc on our modern technological systems, costing the global
economy billions and taking decades to recover. In this study, the solar wind
conditions throughout the event are estimated and used to drive the SNB^3GEO
electron flux model at GEO. The results show a huge increase in flux during
the event, which are discussed along with the implications on the radiation
belts. |
4 |
Oral |
9:45 am |
Influence of EMIC Waves on
Radiation Belt Dynamics |
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Kersten, T1; Horne, R B1; Glauert, S A1; Meredith, N P1 |
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1British
Antarctic Survey |
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Modelling variations in the
earth’s radiation belts depends on capturing some of the most essential
physical processes including particle transport, acceleration and loss. Wave
particle interactions with waves of typically a few Hertz, known as Electromagnetic
Ion Cyclotron (EMIC) waves, are thought to be a significant source of
electron loss at energies greater than about 500keV leading to decay of the
radiation belts. To determine how effective EMIC waves are, we have analysed
data from the fluxgate magnetometer on the CRRES satellite to calculate
bounce averaged pitch angle diffusion rates. The resulting model covers waves
in the equatorial region from about L=4.0 up to about L=7.0 for latitudes up
to 30° and 5 levels of kp between 12-18MLT. We found that these waves could
diffuse electrons into the loss cone very effectively at energies greater
than about 2MeV for pitch angles up to about 60°. The diffusion rates were
included in the BAS Radiation Belt Model together with lower and upper band
chorus waves. Using the model we were able to show that EMIC waves cause a
significant reduction in the electron flux for energies greater than about
2MeV for a range of L-shells from L=4.0-7.0 but only for pitch angles lower
than 60°. We conclude that EMIC waves play an important role in radiation
belt dynamics and therefore should be included in forecasting models. |
5 |
Oral - invited |
10:00 am |
Initial Post‐Flight Results of
the Primary Arcing on Solar Cells At LEO (PASCAL) Flight Experiment |
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Likar, J |
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Lockheed Martin Space Systems |
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Initial Post-Flight Results of
the Primary Arcing on Solar Cells At LEO (PASCAL) Flight Experiment Justin J. Likar , Teppei Okumura , Shunsuke
Iwai , and Mengu Cho Recently, attention
has been paid to the cumulative operational effects of repeated low power
Primary Arcing (PA); a very nice summary is provided by [1]. Round-robin
testing had been previously performed at a number of ground test laboratories
on a standard selection of Silicon and Multi-Junction (MJ) GaAs space solar
cells per methodology summarized in the ISO Standard for ESD Testing of Space
Solar Arrays [2]. Ground test results
to date have been quite informative suggesting that advanced technology
cells, which employ more junctions, are more susceptible to the degrading
effects of primary arcs at the cell perimeter. Such testing and related analytical studies
have provided insight into potential mechanisms for PA induced cell
degradation while also parameterizing some effects as a function of PA
energy, number, and cell type. The
Primary Arc effects on Solar Cells At LEO (PASCAL) flight experiment was
included in the Materials Interaction Space Station Experiment 8 (MISSE-8)
payload as part of the U.S. Naval Research Laboratory (NRL) developed
Platform for Retrievable Experiments in a LEO Space Environment (PRELSE). The MISSE-8 payload, including PASCAL, was
launched aboard STS-134 on 16 May 2011 and deployed via Extra-Vehicular
Activity (EVA) on 20 May 2011. The
experiment was active for approximately two years before being retrieved to
the ISS interior on 9 July 2013. The
entire payload was returned to earth at completion of the Space-X3 Commercial
Resupply flight, splashing down on 18 May 2014. PASCAL scientific objectives were many
fold: 1. Characterize solar cell
degradation as a function of primary arc quantity. 2. Characterize influence
of solar cell design on degradation, if observed, due to primary arcs. 3.
Characterize solar cell degradation, if observed, as function of primary arc
energy. 4. Characterize primary arc waveforms. 5. Identify arc inception
voltage for various solar cell designs.
The basic concept of the PASCAL is the miniaturization of the common
ground experiment system well described in many publications (see references
in [2] for example). PASCAL includes
ten independently controllable solar cells.
Cells have been selected to represent a variety of different solar
cell constructions, shapes, technology levels, and cell manufacturers
(Tecstar Si, Tecstar MJ GaAs, Emcore ATJM, Emcore ZTJM, Spectrolab UTJ, and
Spectrolab XTJ). Specific cells
selected for test have been pulled from Lockheed Martin “flight stock” and as
such can be labeled as offering a very good representation of cells used on
modern spacecraft programs. Cells include Coverglass, Interconnects (i.e.
they are CICs), and various coverglass coatings. PASCAL CICs include
encapsulated interconnectors and turnarounds wherefore the only exposed metal
exists at the cell perimeter. PASCAL enables selection of individual solar
cells to study by changing the status of a number of mechanical relays. Primary Arc (PA) energy is variable between
1.2 mJ and ~45 mJ noting that a primary arc energy of ~45 mJ is reported as
enough energy to cause the degradation of solar cell. Over approximately two
years of continuous operation PASCAL has been demonstrated effective in
generating repeated primary arcs aboard the ISS. Results have enabled determination of
primary arc inception threshold and arc rate.
On-orbit and on-ground LIV results offer important results with
respect to effects of repeated low power primary arcs on cell
performance. Non-destructive and
destructive inspection and cell analyses, performing beginning in June 2014
offer additional insights into degradation mechanisms which may become of
increased importance with recent trends toward low-thrust (All EP) propulsion
and higher power spacecraft. 1.
Vayner, B. and Galofaro, J. “Possible Decline in Solar Array Performance Due
to Electrostatic Discharges in Orbit.”
Presented at 51st ASM, January 7-10, 2013. 2. “Space Systems – Space
Solar Panels – Spacecraft Charging Induced Electrostatic Discharge Test
Methods.” ISO-CD-11221, ISO/TC20/SC14. |
6 |
Oral - invited |
11:30 am |
Science and Data for Defining
Space Weather Impacts to Satellite Operations |
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Green, J1; Rodriguez, J2; Redmon, R3; Guild, T4; Gannon, J1; Olsen, A1 |
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1Geosynergy,
LLC; 2CIRES/NOAA;
3NOAA; 4Aerospace
Corporation |
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The particle radiation that
surrounds Earth presents an extremely harsh environment that satellites must
be designed to withstand and that operators must monitor to ensure continuous
service. Building resilient satellites and achieving uninterrupted operations
is often challenging because the regular extreme fluctuations in the
environment are not well understood and available particle radiation
measurements can be difficult to interpret.
To overcome these challenges, we report on an effort to transform
long-term measurements into more useful products for both scientific
understanding and operations. More specifically, we discuss the
transformation of the NOAA GOES and POES particle flux measurements to
cleaned phase space densities (PSD) relevant for understanding internal
charging effects and radiation belt physics. The benefit of PSD data is that
it should remain constant even as the global magnetic field topology changes
making it easier to identify true global changes in the radiation belts and
the internal charging hazard. Additionally, we discuss the perils of the
measurements and efforts to clean the data and make users aware of
uncertainties. Lastly, we review measurements of the lower energy particle fluxes
and implications for surface charging. |
7 |
Oral - invited |
11:45 am |
Energetic Particle Sensors for
Anomaly Attribution and Environmental Specification (CEASE & RHAS) |
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Lindstrom, C1; Huston, S2; Johnston, R W1 |
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1Air
Force Research Labratory; 2Atmospheric And Environmental Research, Inc |
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The energetic particle
environment is known to cause anomalies on satellites and spacecraft. Many of these anomalies are minor and can
easily be dealt with operationally; however, there are well documented cases
that have had significant effects on the mission of the space vehicle. In addition, the energetic particle
environment creates significant constraints on spacecraft design that
consequently cause increased mission cost.
A key issue is the design trade space for the system designer and a
known concern is the uncertainty in existing space environmental models. Traditionally, the approach to address this
is to use targeted scientific missions to aid in the understanding of the
environment and better develop an understanding of a specific environmental
variable or variables. Additionally, a
few national class assets such as NOAA’s GOES satellites have been deployed
to particularly valuable locations to provide warnings for the global space
community. Clearly, this leads to
problems in data scarcity both temporally and spatially in the near earth
space environment. AFRL identified a
potential solution to this in the mid-1990s by developing the Compact
Environmental Anomaly Sensor (CEASE).
It consists of multiple sensors based on well-established technology
integrated in a small package (~ 4”x4”x4” for CEASE I) that could measure the
portions of the energetic environment responsible for most spacecraft
anomalies. Although it could not rival
the precision of scientific instruments for specific applications it was
intended to be a secondary payload on multiple host satellites for a much
larger data network. The history of
CEASE will be briefly reviewed. This
will be followed by an in-depth illustration of recent CEASE measurements
from TACSAT-4 that demonstrate its ability to both resolve anomalous
degradation in an onboard solar cell experiment and how the data can be used
to improve the AP9 climatology model.
This will also be used to pose challenges that still exist to using
these types of instruments such as how to get timely and relevant information
to the satellite operator. Finally,
the issue of how to improve both the quality and number of energetic particle
sensors will be addressed in AFRL’s follow on to CEASE called CEASE RR and
the Radiation Hazard Awareness Sensor (RHAS) based on Teledyne
microdosimeters. |
8 |
Oral - invited |
12:00 pm |
SKYNET Operations and Space
Weather |
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Swinburne, B1 |
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1Airbus
Defence and Space, CIS, UK Gov |
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Airbus Defence and Space, CIS,
UK Gov (formally Paradigm Services) operates a fleet of eight geostationary
satellites providing secure communication services to both UK Government and
other 3rd party government organisations around the world. As a responsible operator Airbus D&S
spacecraft operations believe it essential for reliable service provision to
perform good Space Situational Awareness maintaining an up to date, accurate,
space picture, part of which being the monitoring/prediction of the local
environment around Airbus D&S space and ground assets. This paper will discuss current Airbus
D&S space weather activities and outline areas where further
development/collaboration may be performed in the future. |
9 |
Oral |
12:15 pm |
The AE9/AP9 Next Generation
Radiation Specification Models – Progress Report |
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Quinn, R1; O'Brien, P2; Johnston, W3; Ginet, G4; Huston, S1 |
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1AER;
2Aerospace; 3Air Force Research
Laboratory; 4MIT
Lincoln Labs |
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The AE9/AP9 model has now been
released to the global satellite design community. Since the release of
version 1.0, we have been focused on documenting the model so that it is
suitable for consideration as an international standard. We are also working
on incorporating new data sources, such as THEMIS, TACSAT-4, and NASA’s Van
Allen Probes. Finally, we are scoping out architectural improvements to
enable improvements requested by industry: improved stitching between the
plasma and radiation models, local time dependence in the plasma model,
longitude dependence in the electron radiation model, and solar cycle
variation in the low altitude protons. We provide a brief update on the
status of the model, plans for the future, and progress on international agreements. |
10 |
Oral |
12:30 pm |
Confronting the AP9/AE9
Radiation Belt Models with Spacecraft Data and other Models |
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Heynderickx, D1; Truscott, P2; Evans, H3 |
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1DH
Consultancy; 2Kallisto
Consultancy; 3ESA/ESTEC |
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Usage of the AP9/AE9 model (now
commonly referred to as IRENE) 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. A thorough evaluation of the new models has
been performed under ESA Contract No 4000108483/13/NL/AK. On the one hand,
data from the AZUR/EI-88, SAMPEX/PET, CRRES/MEA, Giove-B/SREM and
Integral/IREM were directly compared to model runs (Ax-9 MAX/MIN, UP-8/MAX,
PSB97, Ax-9 mean and confidence levels) over the dataset ephemeris. These
datasets, with the exception of CRRES/MEA, were not used in the construction
of the IRENE models and cover a variety of orbit types. On the other hand,
SPENVIS runs were performed using the various models for a series of orbit
types (LEO, MEO, GTO, HEO, GEO). The model spectra were compared, and used as
inputs for the SPENVIS radiation effects models (TID, TNID, damage equivalent
electron fluences, DICTAT). |
11 |
Oral - invited |
12:45 pm |
SpacePy and LanlGeoMag -
Software Libraries for Space Science Data Analysis, Modelling and Space
Weather Forecasting |
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Morley, S1; Henderson, M1; Niehof, J2; W., D3; Larsen, B1 |
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1Los
Alamos National Laboratory; 2University of New Hampshire; 3University of Michigan |
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Common to both space weather
forecasting and scientific analysis of in-situ data from Earth's
magnetosphere are a number of key computational tasks. Two software projects
at Los Alamos have been widely adopted for projects ranging from scientific
research to science mission operations and space situational awareness
applications. These are SpacePy and LanlGeoMag, which are written in Python
and C respectively, and both have recently been made available as open-source
software on unrestrictive licences. These projects cover: managing data and
metadata, running empirical models, converting between time/coordinate
systems, calculating adiabatic invariants and much more. We will present an
overview of the capabilities of these libraries and give examples of their
use in major space weather projects at LANL, such as the Dynamic Radiation
Environment Assimilation Model (DREAM) and magnetic ephemeris calculation for
NASA's Van Allen Probes and Magnetospheric Multiscale (MMS) mission. |
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