SPCE 5065 Spacecraft Interactions Project 28 August Douglas Hine

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Prosper Paul
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1 SPCE 5065 Spacecraft Interactions Project 28 August 2013 Douglas Hine 1. Briefly describe the MSISE-00 and IRI-2001 models. Describe in terms of the following parameters: data used to develop the model, parameters used to obtain relevant results, assumptions and limitations of the model, and accuracy of the results obtained. This will require a literature search. MSISE-00 The MSISE-00 was developed by the Naval Research Laboratory (NRL) as a Mass Spectrometer- Incoherent Scatter Radar (MSIS) class atmospheric density model. It is an empirical, global model that models temperatures and atmospheric densities and its components from the ground to the exosphere. NRLMSISE-00 accounts for the main drivers of the upper atmosphere: the solar extreme ultraviolet (EUV) flux and geomagnetic heating. The 10.7-cm solar radio flux (F10.7) is the standard proxy for the solar EUV, while the Ap daily geomagnetic index measures the geomagnetic component of space weather. [Ref 1] The NRLMSISE-00 mode incorporates orbital drag, satellite accelerometer data and incoherent scatter radar observations covering more than a solar cycle. The inclusion of drag data required the code to account of high altitude O + and hot atomic oxygen components. The model includes data on temperature and molecular oxygen number density. This code needs a time input to reflect the current state of the atmosphere. It also accounts for fluctuations in the atmosphere from latitude, longitude, F10.7, the 81-day average F10.7 and the geomagnetics from the Ap index. MSIS-class models do not maintain a hydrostatic equilibrium, the model generation process imposes an approximation. [Ref 3] It has been extensively tested against experimental data by the international scientific community. NRLMSISE-00 has also been compared to the previous MSIS models and Jacchia- 70. The comparisons are very favorable; however, MSISE-00 clearly demonstrates its dependence on solar and geometric activity over the previous models. IRI-2001 The International Reference Ionosphere (IRI) 2001 model is an international project sponsored by the Committee on Space Research (COSPAR) and the International Union of Radio Science (URSI). For given location, time and date, IRI provides monthly averages of the electron density, electron temperature, ion temperature, and ion composition in the altitude range from 1

2 500 km to 2000 km. [ref4] The 2001 model includes new options for D region electron density, a better representation of electron density in the region between E valley and F2 peak, inclusion of the storm time updating model for the F2 peak, a new option for electron temperature, and an ion drift model. IRI-2001 uses data from 3 Interkosmos satellites and rocket data for the various sub models. The IRI model has been validated with a large amount of data including data from the most recent ionospheric satellites (KOMPSAT, ROCSAT and TIMED) and data from global network of ionosondes. [Ref 7] Inputs include time, latitude, longitude, altitude, day of year, daily F10.7 number and sunspot number and year. The GPS ionospheric reconstruction results are used to compare then results obtained with the IRI-2001 model in South Korea in terms of NmF2 and TEC. The monthly averaged diurnal values of these key parameters in January, April, July and October 2003 are considered to represent the winter, spring, summer and autumn seasons, respectively. Compared with the GPS reconstruction results, averaged monthly NmF2 medians from the IRI-2001 are overestimated in daytime and underestimated in nighttime for all seasons, but the deviation magnitudes in autumn and winter are smaller than in spring and summer. In addition, averaged monthly TEC medians from the IRI-2001 are overestimated in daytime in winter, but almost always underestimated in other seasons. [Ref 5] The measurement data coverage from January to December of a low solar activity year (2006) is analyzed based on the diurnal, seasonal variation and then compared with IRI-2001 model predictions. Generally, the fof2 obtained from the IRI (URSI and CCIR) model closely follows observed for fof2 values. [Ref 6] The IRI 2001 model was able to reproduce well density profiles in the mid-latitude region, on the other hand, it tended to overestimate in the equatorial region. As a result of the comparison with the Akebono satellite sounder data, it was confirmed that the IRI model generally tended to reproduce observed profiles well in lower altitude region (<1000 km) and overestimate in higher altitude region (>1000 km). However, even below 1000 km, the IRI model also overestimated in the magnetic latitude range from 50 to 20. [Ref 8] 2

3 2. Using the MSISE-00 model, plot the total mass density of the upper atmosphere from 200 to 1000 km altitude for F10.7 = 140 sfu and Ap = 15 nt. Plot the same parameter for F10.7 = 220 sfu and Ap = 15 nt. How does the total mass density as a function of altitude change with the F10.7 flux? Mass Density Upper Atmosphere 140 sfu 220 sfu Total Mass density (g cm-3) Altitude (km) Figure 1. Total mass density plot. The total mass density increases with increasing F10.7 flux over the altitude range of km. The model also clearly shows the decrease in atmospheric density as altitude increases. I was also curious on how well the NRLMSISE-00 code compared with a standard density table I ve been using in my astrodynamics projects. Mainly, the exponential atmospheric model table from Vallado (page 564) which uses the CIRA-72. Figure 2 shows the SPENVIS MSISE-00, and NRLMSISE-00 from the Matlab aerospace toolkit 3

4 and the CIRA-72 based table. I used the 140sfu F10.7 and Ap=15 from Figure 1. It looks like a good agreement on the shape of the curve. I suspect the delta between the curves would suggest a slightly higher F10.7 value as nominal for the CIRA-72 model Mass Density Upper Atmosphere, F10.7=140 SFU, Ap=15 CIRA-72 SPENVIS MSISE-00 Total Mass density (kg m-3) Altitude (km) Figure 2. Atmospheric Model Comparison I also wanted to see if NRLMSISE-00 would portray the diurnal bulge of the atmosphere. Figure 3 below is a plot of latitude and longitude, 350 km at 0000 UTC. Since it s midnight UTC, I d expect to see a decrease in atmospheric density at the prime meridian, which Figure 3 clearly shows. As the time is increased from 0000 UTC to 1800 UTC (Figure 6), the bulge rotates with the rotation of the earth. 4

5 Atmosphere Density, 1 Jul :00:00, 350 km, F10.7=140, Ap= Latidude, deg Longitude, deg Figure 3. Atmospheric Density, 1 Jan 2013, time=0000. Atmosphere Density, 1 Jul :00:00, 350 km, F10.7=140, Ap= Latidude, deg Longitude, deg Figure 4. Atmospheric Density, 1 Jan 2013, time=

6 Atmosphere Density, 1 Jul :00:00, 350 km, F10.7=140, Ap= Latidude, deg Longitude, deg Figure 5. Atmospheric Density, 1 Jan 2013, time=1200. Atmosphere Density, 1 Jul :00:00, 350 km, F10.7=140, Ap= Latidude, deg Longitude, deg Figure 6. Atmospheric Density, 1 Jan 2013, time=

7 The output in Figures 1-6 are from the MATLAB version of the NRL MSISE-00 that resides in the Aerospace Toolbox, R2013a. I modified the code to accept the same values that were used in the SPENVIS intranet version. It allowed me to easily create line and 2d plots. The MATLAB code is included in the Appendix. Appendix A has a few plots of the Atmospheric mass density varying latitude and altitude (Figure A1), varying Longitude and altitude (Figure A2) and varying day of year and altitude (Figure A3). I didn t see anything unexpected, just putting MSISE-00 through its paces. 7

8 3. Using the IRI-2001 model, plot the electron, ion and neutral temperatures as a function of F10.7 flux at 350 km altitude. Is the plasma at this altitude in local thermal equilibrium? Is the plasma quasi-neutral? Figure 7. Electron Temperature, F10.7, lat=0, Long=0, time=0 8

9 Figure 8. Ion Temperature, F10.7, lat=0, Long=0, time=0 9

10 Figure 9. Neutral Temperature, Lat = 0, Long = 0, time =0. Since the above graphs were run at Lat=0, Long=0, I was curious how this varied. Figure 10 shows there is a considerable difference as the latitude and longitude changes. 10

11 Figure 10. Electron Temperature, 350 km The electron temperature does vary with time as Figures 10 and 11 shows. Figure 11, next page, shows the evolution of the density at 1200 UTC. I would have expected that the temperature would change as the earth rotates about the sun. (Figures 10 and 11 were created in SPENVIS) 11

12 Figure 11. Electron Temperature, 350 km, 1200 UTC Is the plasma at this altitude in local thermal equilibrium? Thermal equilibrium means that the temperature within the system is spatially and temporally uniform. From figures 7 thru 9, the temperature is constant with respect to changes in the F10.7 values. However figures 10 and 11 above show that the temperature of electrons does change with latitude, longitude and as a function of time. So I gues it would depend on one s definition of local. Is the plasma quasi-neutral? Yes, the plasma can be treated as being electrically neutral. 12

13 4. Using the Atmosphere and Ionosphere models in the SPENVIS package, calculate the atomic oxygen number flux (per unit area) to a ram facing surface on a spacecraft at 350 km altitude. Assume F10.7 = 140 sfu and Ap = 15 nt. AO number flux = # density x orbital velocity Orbital Velocity = = = km/sec = cm/sec Atmosphere model: NRLMSISE-00 Grid type: single point Daily F 10.7 flux for previous day: W m -2 Hz Day average of F 10.7 flux: W m -2 Hz -1 Daily A p : 15.0 (2nT) Table 1. NRLMSISE-00 Inputs Latitude = 0 deg, Longitude = 0 deg, UTC = 00:00:00 Altitude (km) Day of year O Density (cm -3 ) AO Number flux E E E E E E E E E E E E E E E E E E E E E E E E E E+14 Table 2. AO density and AO Number Flux varied by DOY 13

14 2.3 x 1014 Atomic Oxygen Number Flux, alt=350 km, F10.7 = 140 sfu, Ap = Number Flux Day of the Year Figure 12. Graph of AO number Flux 14

15 A satellite was launched in January The spacecraft was launched into a circular orbit with an altitude of 350 km. The orbital inclination is Characterize the environment using the MSISE-00 code. 5. How much additional propellant would be required for drag makeup if the maximum condition prevails over the nominal condition? Assume that the dry mass of the spacecraft is 300 kg and a typical chemical thruster (Isp=240 sec) is used. h= 350 km, m=300 kg, Isp = 240 sec. Assume: Cd= 2.2 and A = 1 m 2 Using SPENVIS MSISE-00 to determine nominal and maximum density conditions. Atmosphere model: NRLMSISE-00 Grid type: single point Daily F 10.7 flux for previous day: W m -2 Hz Day average of F 10.7 flux: W m -2 Hz -1 Daily A p : 4.0 (2nT) Table 3. NRLMSISE-00 Inputs Altitude (km) Mass Density (g cm -3 ) Day of year E Table 4. Atmospheric Density, Day of Year = 1 (1 Jan) Tables 3 and 4 show the input and mass density for the nominal condition case. I choose 1 Jan 11 as the representative case. I then went to NOAA s website and looked to see the worst case solar conditions were in It showed the maximum F10.7 occurred on/about 24 Sep 2011 (DOY=276). This yielded a mass density of e-15 g/cm 3, which I used in the propellant usage calculations Atmosphere model: NRLMSISE-00 Grid type: single point Daily F 10.7 flux for previous day: W m -2 Hz Day average of F 10.7 flux: W m -2 Hz -1 Daily A p : 4.0 (2nT) Table 5. NRLMSISE-00 Inputs 15

16 Altitude (km) Mass Density (g cm -3 ) Day of year E E E Table 6. Atmospheric Density, 350 km altitude, DOY m = - v 2 Cd A / 2 v x t Let t = *86400 sec = 31,557,600 sec v = Isp g = 240sec (9.8 m/sec 2 ) = 2352 m/sec = km/sec Cd=2.2, A=1m 2 At 350 km, v=7.697 km/sec Using nominal density, = e-15 g/cm 3 and max condition, = e-15 g/cm 3 produces Table 7. Nominal 1 Jan 2011 Altitude F10.7 F10.7 avg Ap Avg Density (g/cm 3 ) Propellant Used 350 km e kg Max 24 Jan 2011 Altitude F10.7 F10.7 avg Ap Avg Density (g/cm 3 ) Propellant Used 350 km e kg Table 7. Propellant Used 16

17 6. Mission planners have come to you for an assessment of environmental issues on spacecraft if it were placed in a polar orbit of the same height. Using the resources available to you, provide this assessment. Polar orbit, Inclination ~ 90 o Altitude = 350 km Solar Environment Effect Assessment Rational Vacuum Solar UV Min Possible degradation from UV, solar arrays Outgassing / Contamination Relevant Most materials outgas over several days. Not altitude dependent. Neutral Aerodynamic Drag Important Orbit will perturb due to drag. Density on the order of to kg/m 3. Need propellant to make-up altitude. Sputtering Relevant Neutral molecules impacting spacecraft severing chemical bond of surface material. Atomic Oxygen Relevant Atomic Oxygen predominate species at 350 km altitude. Will cause certain materials to erode. Plasma Spacecraft Charging Relevant Plasma lower energy in LEO. Potential for EMI from arc discharging, dielectric breakdown, surface and internal charging. Radiation Van Allen Belts Important Single event upsets (SEU) possible. Total dose concerns. South Atlantic Anomaly is also a concern. Galactic Cosmic Rays Important Low flux but high energy. Potential for SEUs Solar Proton Important Coronal Mass Ejections (CME)s. Protons dominate potential for high radiation. MMOD Impacts Relevant Debris increases at lower altitudes. 300,000 1cm pieces below 2000 km. Potential for micrometeorids. Table 7. Space Environment Effects, 350km altitude, polar orbit 17

18 7. Mission planners are now considering a semi-synchronous (higher altitude), equatorial orbit and need an assessment of environmental issues on the spacecraft. Using the resources available to you, provide this assessment. Semi-Synch orbit, Inclination ~ 0 o Altitude ~ 20,200 km Solar Environment Effect Assessment Rational Vacuum Solar UV Relevant Solar array / material degradation Outgassing / Contamination Relevant Most materials outgas over several days. Not altitude dependent. Neutral Aerodynamic Drag Not relevant N/A Sputtering Relevant Neutral molecules impacting spacecraft severing chemical bond of surface material. Atomic Oxygen Not Relevant Mostly He and H at this altitude. O ~ g/cm 3 Plasma Spacecraft Charging Important Plasma energy higher in MEO. Potential for EMI from arc discharging, dielectric breakdown, surface and internal charging. Radiation Van Allen Belts (Trapped) Relevant Total dose concerns, especially for longer duration missions. Galactic Cosmic Rays Important Low flux but high energy. Potential for SEUs Solar Proton Important Coronal Mass Ejections (CME)s. Protons dominate potential for high radiation. Effects greater at higher altitudes. MMOD Impacts Relevant Potential for micrometeoroids. Debris not as much of a concern as at lower altitudes. Table 8. Space Environment Effects, Semi-Synch Altitude, Zero Inclination 18

19 REFERENCES 1. J.M. Picone, A.E. Hedin, D.P. Drob, and J. Lean, NRLMSISE-00 Empirical Atmospheric Model: Comparisons to Data and Standard Models, AAS , Lisa A. Policastri and Joseph M. Simons, Implementing the MSIS Atmospheric Density Model in OCEAN, AAS J.M. Picone, A.E. Hedin, and D.P. Drob, NRLMSISE-00 Empirical Model of the Atmosphere: Statistical Comparisons and Scientific Issues, Journal of Geophysical Research, Dec International Reference Ionosphere Homepage, NASA Goddard Space Flight Center, accessed 1 August Jin, S; Park, J-U, GPS Ionospheric Tomography: A Comparison with the IRI-2001 model over South Korea, The Smithsonian/NASA Astrophysics Data System. accessed 1 Aug Wichaipanich, N. ; Boonchuk, T. ; Leelaruji, N. ; Hemmakorn, N., Comparison between fof2 observations and IRI-2001 model predictions at Thailand equatorial latitude station, DOI: /ECTICON Dieter Bilitza, The International Reference Ionosphere Climatological Standard for the Ionosphere, In Characterising the Ionosphere (pp ). Meeting Proceedings RTO-MP-IST-056, Paper 32. Neuilly-sur-Seine, France: RTO., p J. Uemoto, A. Kumamoto, M. Iizima, Comparison of the IRI 2001 model with electron density profiles observed from topside sounder on-obard the Ohzora (EXOS-C) and the Akebono (EXOS-D) satellites, Advances in Space Research, Vol 39 Issue 5, 2007, pages

20 APPENDIX A Mass Density Charts Total Mass density (kg m-3) Mass Density Upper Atmosphere, F10.7=140 SFU, Ap= km 400 km 600 km 800 km 1000 km Latitude, deg Figure A1. Vary Latitude and Altitude Total Mass density (kg m-3) Mass Density Upper Atmosphere, F10.7=140 SFU, Ap= km 400 km 600 km 800 km 1000 km Longitude, deg Figure A2. Vary Longitude and Altitude 20

21 Total Mass density (kg m-3) Mass Density Upper Atmosphere, F10.7=140 SFU, Ap= km 400 km 600 km 800 km 1000 km Day of Year Figure A3. Day of Year and Altitude APPENDIX B Matlab Code To generate Figures 1 and 2 SolarFlux.m %Project SPCE 5065 clear all; clc %format long g constastro1; %Plot Density verses altitude varying F107 load rhoalt.txt; load rho100_0.txt; load rho140_0.txt; load rho220_0.txt; rho140kgm3=rho140_0*1000; %convert g/cm3 to kg/m3 rho220kgm3=rho220_0*1000; figure(1) %semilogy(rhoalt,rho100_0,'--'); hold on; semilogy(rhoalt,rho140_0); hold on; 21

22 semilogy(rhoalt,rho220_0,'g'); hold on; %legend('100 sfu','140 sfu','220 sfu') legend('140 sfu','220 sfu') xlabel('altitude (km)');ylabel('total Mass density (g cm-3)') title('mass Density Upper Atmosphere') i=1; for j=200:10:1000 r=j+re; rho72(i) = Density72( r ); i=i+1; end i=1; for j=200:10:1000 h=j*1000; [T rho] = atmosnrlmsise00mod( h, 0, 0, 2012, 1, 0,'None'); rhoms(i)=rho(6); i=i+1; %fprintf('%4d %1.4e\n',j,rho(6)) end figure(2) semilogy(rhoalt,rho72,':k'); hold on; semilogy(rhoalt,rho140kgm3); hold on; semilogy(rhoalt,rhoms,'g'); hold on; legend('cira-72','spenvis','msise-00') xlabel('altitude (km)');ylabel('total Mass density (kg m-3)') title('mass Density Upper Atmosphere, F10.7=140 SFU, Ap=15') Function Density72 produces CIRA72 atmospheric density function [ rho ] = Density72( r ) %Calculate Atmospheric Density, CIRA-72 %Vallado, %Input: Position vector magnitude, km %Output: density, Rho, kg/m^3 constastro1 hellp=r-re; if hellp >= 1000 ho=1000; rho0=3.019e-15; H=268.0; %disp('altitude >1000 km'); elseif hellp <= && hellp >= 80. ho=80; rho0=1.905e-5; 22

23 H=5.799; %disp('80-90'); elseif hellp <= && hellp >= 90. ho=90; rho0=3.396e-6; H=5.382; %disp('90-100'); elseif hellp <= && hellp >= 100. ho=100; rho0=5.297e-7; H=5.877; %disp(' '); elseif hellp <= && hellp >= 110. ho=110; rho0=9.661e-8; H=7.263; %disp(' '); elseif hellp <= && hellp >= 120. ho=120; rho0=2.438e-8; H=9.473; %disp(' '); elseif hellp <= && hellp >= 130. ho=130; rho0=8.484e-9; H=12.636; %disp(' '); elseif hellp <= && hellp >= 140. ho=140; rho0=3.845e-9; H=16.149; %disp(' '); elseif hellp <= && hellp >= 150. ho=150; rho0=2.070e-9; H=22.523; %disp(' '); elseif hellp <= && hellp >= 180. ho=180; rho0=5.464e-10; H=29.740; %disp(' '); elseif hellp <= && hellp >= 200. ho=200; rho0=2.789e-10; H=37.105; %disp(' '); elseif hellp <= && hellp >= 250. ho=250; rho0=7.248e-11; H=45.546; %disp(' '); elseif hellp <= && hellp >= 300. ho=300; rho0=2.418e-11; H=53.628; %disp(' '); 23

24 elseif hellp <= && hellp >= 350. ho=350; rho0=9.518e-12; H=53.298; %disp(' '); elseif hellp <= && hellp >= 400. ho=400; rho0=3.725e-12; H=58.515; %disp(' '); elseif hellp <= && hellp >= 450. ho=450; rho0=1.585e-12; H=60.828; %disp(' '); elseif hellp <= && hellp >= 500. ho=500; rho0=6.967e-13; H=63.822; %disp(' '); elseif hellp <= && hellp >= 600. ho=600; rho0=1.454e-13; H=71.835; %disp(' '); elseif hellp <= && hellp >= 700. ho=700; rho0=3.614e-14; H=88.667; %disp(' '); elseif hellp <= && hellp >= 800 ho=800; rho0=1.170e-14; H=124.64; %disp(' '); elseif hellp <= && hellp >= 900. ho=900; rho0=5.245e-15; H=181.05; %disp(' '); else disp('other altitude Not covered in table'); end rho=rho0*exp(-(hellp-ho)/h); end Matlab script to produce the density plots DensityContour.m %Contour plot %Atmos Density 24

25 %h=350km %F10.7/a = 140 sfu, Ap =15 %2013 Jan 1 clear all; clc format long g i=1; for long=-180:180 j=1; for lat = -90:90 [T rho] = atmosnrlmsise00mod( , lat, long, 2013, 182, 64800,'None'); den(i,j)=rho(6); j=j+1; end i=i+1; end lat=-90:90; long=-180:180; [LA,LO]=meshgrid(lat,long); pcolor(lo,la,den) shading interp xlabel('longitude, deg') ylabel('latidude, deg') title('atmosphere Density, 1 Jul :00:00, 350 km, F10.7=140, Ap=15') %Plot coastline hold on; x = load('coastline.dat'); plot(x(:,1),x(:,2),'w') 25

MAE 5595: Space Environments and Spacecraft Interactions. Lesson 4: Introduction

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