COE CST First Annual Technical Meeting: Space Environment MMOD Modeling and Prediction. Sigrid Close. Federal Aviation.

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1 Administration COE CST First Annual Technical Meeting: Space Environment MMOD Modeling and Prediction Sigrid Close November 9, 2011 Administration 1

2 Overview Team Members Purpose of Task Research Methodology Results Next Steps Contact Information Administration 2

3 Team Members Sigrid Close, Stanford University Alan Li, Stanford University (graduate student) Administration 3

4 Purpose of Task Spacecraft are routinely impacted by space debris and natural impactors - Mechanical damage: well-known, larger (> 120 microns), rare - Electrical damage: unknown, smaller/fast, more numerous Debris vs. meteoroids threat to LEO spacecraft - Mechanical threat: comparable - Electrical threat: dominated by meteoroids Goal: Characterize impactor population through data analysis and modeling Administration 4

5 Impactors Dust and Meteoroids Space Debris Speeds Speeds: < 12 km/s 11 to 72.8 km/s (interplanetary) Higher densities > 72.8 km/s (interstellar) Varying sizes Densities rocky or ice-like Sizes < 62 microns in diameter (dust) 62 microns to 0.3 m in diameter (meteoroid) Administration 5

6 Methodology: Meteoroids Models: Formation of plasma (PIC), Interaction of electromagnetic waves with plasma (FDTD), Atmosphere Data: Ground-based plasma, in-situ impact Research and Deliverables - Flux - Mass, density - Velocity, orbit Altitude (km) SNR (db) Time (sec) Administration 6

7 Methodology: Debris Models: Propagation of debris in space and time (Force Model), Atmospheric models (MSIS, Jacchia-Bowman) Data: Ground-based/in-situ impact for detection, Lightgas gun for debris source Research and Deliverables - Flux - Source - Prediction Administration 7

8 Radar Data High-power ground-based meteor observations Multi-frequency, multi-polarization, high-sensitivity, high range resolution Radars ALTAIR Arecibo Observatory MIT Haystack EISCAT 8 Administration 8

9 Meteoroid Plasma Modeling Plasma Frequency (MHz) ALTAIR VHF R 2 Plasma Radius (a) (m) Administration 9

10 Meteoroid Results Administration 10

11 Debris Modeling NASA: ORDEM, LEGEND ESA: MASTERS Modeling from sources, propagation, conjunction Newer sources (perhaps hybrids), newest atmospheric models (Jacchia-Bowman) NASA collision model (inadequate in many areas) - No material dependence - No size and shape factor dependence - Velocity distribution inadequate Administration 11 11

12 Debris Results Based upon three primary sources - US Space Command Catalog, Haystack Radar, and in-situ - Auxiliary data provided by HAX radar, Goldstone radar, returned solar array from Hubble Space Telescope Extrapolation based upon EVOLVE for ranges of debris where data is scarce Spatial Density vs Latitude and Altitude for Debris > cm Spatial Density vs Latitude and Altitude for Debris > 10 cm 40 x Spatial Density [no/km 2 ] Altitude [km] Latitude [degrees] S p a tia l D e n s ity [n o /k m 2 ] Altitude [km] Latitude [degrees] Administration 12 12

13 Next Steps Meteoroids - Compressed sensing techniques for improved detection/analysis - Force modeling for improved orbit determination - Electromagnetic scattering models for plasma diagnostics Debris - Characterization of all sources/breakups - Comparison between MASTERS/ORDEM - Propagation and atmospheric models Administration 13

14 Publications Close et al., Determining Meteoroid Bulk Densities Using a Plasma Scattering Model with High-Power Large- Aperture Radar Data, Icarus, in review, 2011 Reference: National Academies Report: Limiting Future Collision Risk to Spacecraft: An Assessment of NASA s Meteoroid and Orbital Debris Programs Administration 14

15 Thank You! Sigrid Close Alan Li Administration 15

16 Backup Administration 16

17 ALTAIR Radar Data 105 VHF UHF Altitude (km) Time (sec) Administration 17

18 Mechanical and Electrical Damage Larger Impactors Mechanical Damage mass density Specs s Electrical Damage Radiated power Faster Impactors plasma strength velocity deceleration 18 Administration 18