# Presentation: 525694

## 
  Joseph Minow
NASA/Marshall Space Flight Center

Dieter Bilitza
Raytheon ITSS

Living With a Star 
Working Group Meeting on New Standard Radiation Belt and 
Space Plasma Models for Spacecraft Engineering
Greenbelt, MD  5-8 October 2004

**  ****Joseph Minow**
**NASA/Marshall Space Flight Center**
**Dieter Bilitza**
**Raytheon ITSS**
**Living With a Star **
**Working Group Meeting on New Standard Radiation Belt and **
**Space Plasma Models for Spacecraft Engineering**
**Greenbelt, MD  5-8 October 2004**

- Low Energy Plasma Environment Models:  Ionosphere and Outer Magnetosphere

## Overview

**Goal of workshop is to complete a roadmap for development of new plasma and radiation models for spacecraft engineering**
**MSFC/Engineering Directorate uses space environment models for engineering support of NASA programs**
**Low energy plasma  (<0.5 MeV) modeling activities:**
**International Space Station:      **
**Ionospheric plasma (Ne, Te) variability**
**Chandra X-ray Observatory:**
**Outer magnetosphere, magnetosheath, and solar wind ion flux model**

## Space Environments Team

**MSFC Engineering Directorate **
**Engineering support group**
**Space environments and effects analysis for NASA programs**
**Use space environment models and data for:**
**Establishing environment definitions and program environment requirements for NASA missions**
**Space environments and effects analysis for spacecraft design and operational support**
**Reducing program risk for anomaly or failure due to the space environment**
**Environments and effects analysis for anomaly, failure investigations**
**Model sources include:**
**Products from space environment modeling community**
**In-house models**

## ISS Charging Issue

**ISS charges negative in ionospheric plasma**
**Current collection from bare interconnects on biased solar arrays**
**160 V solar arrays**
**Pre-flight predictions:   |-********s/c****| ~ 100 to 140 V**
**Pressurized elements grounded to negative end of arrays**
**Dielectric thermal control coatings arc at ~ -80V**
**Possible EVA shock hazard**
**ISS Program spacecraft potential requirements:**
**Control |-********s/c****| < 40 volts (EVA), |-********s/c****| < 60 volts (vehicle)**
**Two Plasma Contactor Units (PCU) installed to control vehicle voltage **
**ISS Program requested analysis of **
**Risk to vehicle, EVA should PCU fail?**
**How often do PCU’s have to be operated?**
**Plasma environment specification required for ISS charging analysis**
**International Reference Ionosphere (IRI) widely used for providing low Earth orbit environments for spacecraft design and mission analysis**
**Climatological model for Ne, Te...only provides a mean environment**
**Require estimate of extreme environments**

## International Space Station

**E = v** x **B**·**l ~ 0.4 V/m**

- [adapted from Barsamian et al., 2003]

**Induction potential**

**Array charging**

## ISS Charging Environment Specification

**Historical Ne, Te satellite measurements used to specify mean, extreme environments for ISS charging study**
**AE-C, AE-D, AE-E, DE-2 from NSSDC**
**Use IRI for **
**Mean Ne, Te environment**
**Ease of Ne, Te predictions along ISS orbit**
**Variability model provides estimates of Ne, Te deviations about mean IRI values**
**ISS specific environment requirements: **
**350 km < z < 450 km**
**-****51.6****°**** < latitude < 51.6****°**** **
**Sunrise, morning, midday**
**low, mid latitude particularly important**
**Ne, Te statistics (“n********” variations about mean) used to constrain charging analysis**

## Satellite Data Set

-   **Satellite ****	****Inclination**
-    AE-C  	    ~68°
-    AE-D  	    ~90°                **- ****55****° < latitude < ****+55****° retained for ISS study**
-    AE-E 	    ~20°
-    DE-2 	    ~90°

- ISS

- [Minow et al., 2003]

## Satellite Data Set for ISS

- AE-C, AE-D, AE-E, DE-2

- [Minow et al., 2003]

## Arecibo Incoherent Scatter Radar

## Arecibo ISR:  data - model

- Difference = Data – IRI Model

## IRI vs Satellite Measurements

** ****|lat| < 51.6    350 km < z < 450 km**

**Blue****:  mean IRI value in bin**
**Green:**** +/- 68%         ****Yellow****:  +/- 95%            ****Red:**** +/- 99.9%**

- [Minow, 2003]

## Variability Model Structure

**IRI_VAR.f**

**irisub.f**

**Lat, lon, z, time, F107/SSN**

**IRI Ne, Te**
******Ne, ********Te**

- Variability model

- IRI-2001 model

** **

** **

** **

** **

******Ne, ********Te database**

## Variability Model Application

-   ISS altitude

- [Minow et al., 2003]

## Ne, Te Scatter Plots

**Max Ne ~ 6 x 10****12**** #/m****3**

**Min Te ~ 0.05 eV**

**350 km < z < 450 km    -55****° ******** latitude ******** ****+55****°      0° <  SZA < 120°**

- [Minow et al., 2003]

**All AE, DE data**

## Worst Case Analysis

**[Barsamian et al., 2003]**

**|********s/c****| ~ -26 V is maximum ISS potential observed to date**

- ISS Plasma Interaction Model  (Boeing-Houston, SAIC)

## Living With a Star

**ISS study only used AE, DE-2 data!**
_**                  **__**Satellite Data (in house)__________**_
- AE-C	150 km    x     4300 km     x  68.1 deg
- AE-D	154 km    x   13816 km     x  90.1 deg
- AE-E	156 km    x     2983 km     x  90.1 deg
- DE 2	300 km    x     1000 km     x  90 deg
**ISS charging study set:                                                      **
- 350 km < z < 450 km
- 0° < SZA < 120°
-      pre-sunrise through daytime
- |lat| < 55o (ISS inc. is 51.6o)

- LWS award funded research program to generalize ISS results using additional data resources

- [Minow et al., 2003]

## Living With a Star Database

_**                  **__**Satellite Data (in house)__________**_
**AE-C****	****150 km    x     4300 km     x  68.1 deg**
**AE-D****	****154 km    x   13816 km     x  90.1 deg**
**AE-E****	****156 km    x     2983 km     x  90.1 deg**
**DE 2****	****300 km    x     1000 km     x  90 deg****	**
**Explorer 22****	****889 km    x     1081 km      x  79.7 deg**
**Explorer 31  500 km     x    3000 km      x  79.8 deg**
**Aeros-A****	****223 km    x       867 km     x  96.9 deg**
**Alouette 2****	****505 km    x     2987 km      x  79.8 deg**
**Aureol 3 ****	****380 km    x     1920 km     x  82.6 deg**
**Hinotori ****	****548 km    x       603 km      x  31.3 deg**
**ISIS-1****	****578 km    x     3526 km      x  88.42 deg**
_**                 **__**Satellite Data (in process)_________**_
**DMSP          835 km    x      835 km       x  98.2 deg**
**2000, 2001, 2002 in hourse**
**1998, 1999**
**CHAMP          454 km  circular x 87 deg**
**2000-2003**** ****	**

_**              **__**Incoherent Scatter Radar Data          .**_
**Arecibo (T/R)****	**** ****18.3N    -66.8E**
**St. Santin (T)                  ****	**** 44.6N       2.2E**
**--Nancay (R) ****	**** 47.4N       2.2E**
**--Mende (R) ****	**** 44.5N     3.45E**
**--Monpazier (R) ****	**** 44.7N       0.8E**
**Millstone Hill (T/R)        ****42.6 N   -71.5E**
**Jicamarca (T/R)           ****-11.95N   -76.0E**
**Irkutsk (T/R)                 ****52.85N   103.1E**
**Karkov (T/R)                   50.0N    36.2E**
**Chatanika (T/R)                65.1N  147.4W**
**Sondrestrøm ****	****67.0 N    -51.0E **
**EISCAT,Tromsø  (T/R)   ****69.6 N     19.2E**
**EISCAT, Svalbard (T/R)      78N     15.7E**

- Data sources:
-  NSSDC/GSFC
-  CEDAR Database
-  AFRL, Aerospace Corporation,
-    Millstone Hill, Cornell University

## ISS Solar Cycle, Altitude Data Coverage

- [Minow et al., 2003]

## LWS Solar Cycle, Altitude Data Coverage

- [Minow et al., 2003]

## International Reference Ionosphere
Status

Dieter Bilitza
Raytheon ITSS

- Status
- Dieter Bilitza
- Raytheon ITSS

## ION COMPOSITION:

- New model for O+, H+, He+, and N+ from 500km to 2500 km based on AE-C, E and IK-24 data

*V. Truhlik,*
*L. Triskova,*
*J. Smilauer (2003)*

**ION COMPOSITION:**

- IRI

- new

- 1000 km, HSA

- O+

- H+

- He+

## Work in Progress:

**• ****Improvements of the N****e**** topside profile and coupling to plasmasphere**
**• ****Quantitative description of ionospheric variability**
**• ****Inclusion of solar cycle variations for temperatures and ion **
**composition**
**• ****Global model for spread-F occurrence probability **

## Applications of IRI Model

**Applications of IRI Model**

## What is Needed

-  A global mapping of the F peak height hmF2 using all available data
-  A global description of positive and negative storm effects on foF2 and hmF2.
-  A more accurate representation of the variation of densities and temperatures over the solar cycle (wavelength-specific solar indices and region-specific ionospheric indices would help).
-  A global model for the occurrence statistics of spread-F and sporadic-E.

## Chandra X-Ray Observatory

## Chandra X-Ray Observatory

- Grazing incidence mirrors focus x-rays onto detector focal plane

- Advanced CCD Imaging Spectrometer (ACIS)

## ACIS Radiation Issue

**Advanced CCD Imaging Spectrometer (ACIS) detector exhibited higher radiation degradation than anticipated early in mission **
**Degradation is increase in charge transfer inefficiency (CTI) of the front illuminated (FI) CCD elements of the detector array**
**No damage observed in back illuminated (BI) CCD elements**
**Damage occurs during traverse of radiation belts/ring currents**
**Degradation is due to damage by 100 keV ****≤  E  ≤****  200 keV protons**
**No direct line of site between ACIS focal plane and external environment**
**Protons scatter off x-ray grazing incidence mirrors to ACIS focal plane**
**Degradation only occurs in the front illuminated CCD in ACIS detector array**
**Protons < 100 keV cannot penetrate the optical blocking filter**
**Protons 100 keV ****≤ E ≤ ****200 keV are stopped in the active gate region of FI CCD’s**
**Protons > 200 keV pass through sensitive region of CCD**
**Ion displacement damage produces electron trapping sites, increased CTI**
**Protons of 100-200 keV are common ring current energies during geomagnetic storms**
**ACIS has to be moved to a shielded position out of the focal plane during radiation belt passages (near orbital perigee)**
**Lost science observing time**

## Radiation Model Requirements

**AP-8, AE-8 used by Chandra program to determine radiation belt boundaries**
**Program desired model for estimating 100-200 keV proton flux in outer magnetosphere as a function of geomagnetic, solar activity (outside of geostationary orbit)**
**AP-8 doesn’t provide asymmetric flux distributions due to E x B, ********B-curvature drifts**
**AP-8 is appropriate only for average trapped proton environments**
**Not very good at energies <100’s keV in outer radiation belts**
**Developed Chandra Radiation Model (CRM)**
**Empirical, database driven model of outer magnetosphere, magnetosheath, and solar wind free field ion flux **
**Only 100-200 keV protons included in CRM**
**CRM applications**
**Incorporated into the CXO off-line mission planning system aid in scheduling ACIS observation periods**
**Maximize science observations time**
**Minimize radiation degradation **
**Provide near real time proton fluence for individual orbits**
**Tool for management of the ACIS detector degradation**

## Data

-     **Energy    Energy Thresh. Set 1     Energy Thresh. Set 2**
**    ****Channel     Min (keV) Mid                  Min  (keV)  Mid               **
**---------------------------------------------------------------------------           **
**         ****0           16.8       18.9                  13.9            15.6**
**         ****1           21.2       24.4                  17.5            19.9**
**         ****2           27.9       32.4                  22.6            26.2**
**         ****3           37.5       43.1                  30.3            35.4**
**         ****4           49.6       57.2                  41.4            48.1**
**         ****5           65.9       76.0                  55.9            55.2**
**         ****6         ****	**** 87.7     102.0                  75.9            88.4**
**         ****7        ****	****118.0     138.0                103.0          121.0**
**         ****8        ****	****161.0     188.0                142.0          168.0**
**         ****9        ****	****221.0     259.0                198.0          234.0**
**       ****10        ****	****303.0     355.0                277.0          327.0**
**       ****11        ****	****417.0     489.0                387.0          459.0**
**       ****12        ****	****574.0     674.0                543.0          643.0**
**       ****13        ****	****791.0     929.0                762.0          903.0**
**       ****14        1091.0   1281.0              1071.0        1269.0**
**       ****15        1505.0   2000.0              1505.0        2000.0**
**---------------------------------------------------------------------------**
**                   ****Current:    1996 – 1999**
**             ****In progress:    2000 – 2004**

**Data**

**Geotail EPIC/ICS**
**Channel     Species                Energy Band   **
**  ****Name                                       (keV/e)  **
**---------------------------------------------------------**
**P2              p+                      58.1   -     77.3**
**P3              p+                      77.3   -   107.4**
**P4              p+                    107.4   -   154.3**
**P5              p+                    154.3   -   227.5**
**P6              p+            ****	****  227.5  -   341.6**
**P7              p+           ****	****  341.6  -   522.5**
**P8              p+            ****	****  522.5  -   813.5**
**P9              p+            ****	****  813.5  - 1560.8**
**P10            p+           ****	****  560.8  - 3005.4        **
**---------------------------------------------------------**
**         ****Current:     1995 – 2001**
**    ****In progress:    2001 – 2004**
**                    **
**                               **

- Data spans nearly a complete solar cycle!

## Proton Flux Dependence on Kp

- Kp 0-2

- Kp 4-6

- Kp 2-4

- Kp 6-9

**Flux units:  #/cm2-sec-sr-MeV**

- [Blackwell et al., 2004]

## Flux Mapping

**Step 1:**   Create a database of “streamline” position points by computing ion test particle drift paths through the magnetosphere:
- conserving both the total energy and the first adiabatic invariant (the magnetic moment).
**Step 2:**    Create a pointer database that allows for rapid mapping of a satellite particle flux measurement to a streamline.
**Step 3:** Generate runtime database using spacecraft (Geotail, Polar) particle flux measurements
- Map flux along field lines assuming isotropic flux distribution

## Mapping

**Day**
**X****GSE**** = 9 R****e****, Y****GSE**** = 1 R****e****, Z****GSE**** = 0 R****e**
**Total flux points:  2191**
**Restricted mapping points:  ~393**

**Night**
**X****GSE**** = -9 R****e****, Y****GSE**** = -1 R****e****, Z****GSE**** = 0 R****e**
**Total flux points:  1978**
**Restricted mapping points:  ~579**

**1999/200.3                      Kp = 3.5                   Dst = -20** nT**                                                              Solar wind proton flux=1x10****4**** #/cm2-sec-sr-MeV           Region =magnetosphere **

## Streamline Flux Mapping 

**Streamline Flux Mapping**** **

- [Blackwell et al., 2004]

- All Z

- All Z

- -1<Z<1

- -1<Z<1

- Raw data

- Mapped

## Geotail Plasma Regime ID

**Geotail/CPI                        University of Iowa CPI/HPA survey plot**

**JHU/APL EPIC/ICS survey plots**

- 100-200 keV

## Plasma Regime Identification Tool

**Processsed: sw_990815_gse.txt**
**  **
**   ****Time (UT)   ID   Region**
- ----------------------------
-   0.00000       1     MS
-   9.57056       1     MS
-   9.58409       2     MP
-   9.59704       1     MS
-   9.62527       2     MP
-   9.66527       1     MS
-   9.69292       2     MP
-   9.78646       1     MS
-   9.86823       2     MP
-   9.88186       1     MS
-  10.4373        2     MP
-  10.4506        1     MS
-  10.7353        2     MP
-  12.4470        1     MS
-  12.5427        2     MP
-  12.5821        1     MS
-  12.6496        2     MP
-  12.7589        1     MS
-  12.7859        2     MP
-  12.8681        1     MS
-  12.9345        2     MP
-  12.9616        1     MS

- Univ. of Iowa Geotail solar wind plasma moments (CPI or SWA) used for regime identifications

## CRM V2 100-200 keV Proton Flux

**Updated CRM V2 output with ACE correlated magnetosphere, magnetosheath database**

**Original CRM V2 including solar proton flux inside of magnetosphere, magnetosheath**

**(Note: original, uncorrelated analytic solar wind model is used for these results.)**

## Fluence Scheduling

**Fluence level to meet ACIS **
**5% CTI increase per year**

- Average fluence (100-200 keV protons) per orbit for 2000

## CTI Increase vs. CRM Proton Fluence

-                    **0              200              400               600               800            1000             1200**

**CTI Increase vs. CRM Proton Fluence**

**CTI increase****:   **
**       ****Red:  measured      **
**   ****Yellow:  CRM prediction**

- (Chandra Operations Center, Harvard-Smithsonian Astrophysical Observatory)

## Summary

**Engineering applications often require tailored models, data analysis for specific applications**
**More general the plasma, radiation model the better chance it has to be of use to engineering community**
**Mean environments                 **
**Percentile environments        **
**Extreme environments**
**Extreme probably still requires access to appropriate data      **
**MSFC/ED applications require a variety of models and data sets**
**Usefulness of a particular model (or data set) often depends on whether we can answer the standard Program Management questions:**
**Do I have a problem?  When do I have a problem?           Solar cycle, K****p**** dependence**
**How big is the problem?  How often does it occur?           Mean, N%, extreme models**
**Can I trust your model?****	****	****	****    Model validation, accuracy, **
**                                                                                                                ****error bars**