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Gregory P. Ginet Space Vehicles Directorate Air Force Research Laboratory

Demonstrations & Science Experiment (DSX) 05 Mar 2009. Gregory P. Ginet Space Vehicles Directorate Air Force Research Laboratory. DSX Outline. Introduction Satellite & Payloads Orbital Coverage CONOPS Status & Summary. DSX Mission Objectives.

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Gregory P. Ginet Space Vehicles Directorate Air Force Research Laboratory

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  1. Demonstrations & ScienceExperiment (DSX) 05 Mar 2009 Gregory P. Ginet Space Vehicles Directorate Air Force Research Laboratory

  2. DSXOutline • Introduction • Satellite & Payloads • Orbital Coverage • CONOPS • Status & Summary

  3. DSXMission Objectives • Nominal orbit: 6000 k x 12000 k,125 deg incl, launch ~ 2012 • Three science experiments: • Wave-particle interactions (WPIx) • Determine efficiency of injecting VLF into space plasmas in situ • Determine global distribution of natural & man-made ELF-VLF waves • Characterize and quantify wave-particle interactions • Space weather (SWx) • Map MEO radiation & plasma environment • Diagnose in-situ environment for wave generation experiments • Space environment effects (SFx) • Quantify effects of MEO environment on new technologies • Determine physical mechanisms responsible for material breakdown

  4. DSXWave-Particle Interactions ELF/VLF Waves Control Particle Lifetimes L shell = distance/RE Particles mirroring below 100 km are “lost” Particle pitch-angle Electromagnetic waves Electromagnetic waves in the Very Low Frequency (VLF) range (3-30 kHz) scatter and accelerate radiation belt electrons through cyclotron resonance interactions Waves from CRRES (1990)

  5. DSXSpace Weather Forecasting Transmitters Particle lifetime along field lines (approximate 1D solution) Diffusion coefficient along field lines Natural VLF Wave power in the magnetosphere Diffusion coefficients along field lines Full 3D global, time dependent particle distributions Xi = (L, E,  ) Distribution of Resonant Wave Vectors Quantitative understanding of VLF wave power distribution & resultant wave-particle interactions is crucial for radiation belt specification & forecasting Wave-particle resonance condition Complex dependence on energy, frequency, and pitch angle Diffusion coefficients = sum over resonances

  6. DSXVLF Injection Efficiency Isheath + - - - - + + - + - - + > 0 0 > - - - Iantenna + - + + + Electrostatic potential (Volts) +300 +10 -10 VLF loop antenna -10000 • VLF antennas in plasma are very different than in vacuo: • Sheaths form around elements due to free electrons & ions • High-power levels can heat local plasmas • Far-field radiation a result of complex current distribution • Several modeling approaches being taken • Analytic impendence theory with 1-D sheath & empirical tuning (UM/Lowell) • Dynamic 3-D “electrostatic” simulations with NASCAP-2K (SAIC) • 3-D FDFD electromagnetic simulations with PML’s (Stanford) • Linear-response cold plasma theory in far-field (Stanford, UM/Lowell, AFRL, etc.) • Validation with LAPD in laboratory plasmas (UCLA) 3-D FDFD antenna simulation (Stanford) 3-D electrostatic antenna simulation (NASCAP-2k, SAIC) 1-D equivalent circuit (UMass/Lowell) Current models predict wildly different scaling of power output with frequency & antenna length - DSX will provide validation

  7. DSXCurrent Standard Models (AE8 & AP8) Example: Medium-Earth Orbit (MEO) Example: Highly Elliptic Orbit (HEO) (>2.5 MeV e ; >135 MeV p) Dose Rate (Rads/s) Behind 0.23” Al J. Fennell, SEEWG 2003 L (RE) • For MEO orbit (L=2.2), #years to reach 100 kRad: • Quiet conditions (NASA AP8, AE8) : 88 yrs • Active conditions (CRRES active) : 1.1 yrs • AE8 & AP8 under estimate the dose for 0.23’’ shielding HEO dose measurements show that current radiation models (AE8 & AP8) over estimate the dose for thinner shielding Model differences depend on energy: Omni. Flux (#/(cm2 s Mev) L (RE) L (RE) L (RE) L (RE)

  8. DSXWhere is the 20 dB? Starks, et al. (2008) Abel & Thorne (1998) ≠ Ground transmitter VLF needed in the inner magnetosphere… but where is it?

  9. 40 m 40 m Radiation Belt RemediationDSX Satellite • Wave-Particle Interactions (WPIx) • VLF transmitter & receivers • Loss cone imager • Space Weather (SWx) • 5 particle & plasma detectors • Space Environmental Effects (SFx) • NASA Space Environment Testbed • AFRL effects experiment • AC Magnetometer • Tri-axial search coils FSH 8 m • Z-Axis Booms • VLF E-field Rx HST • ESPA Ring • Interfaces between EELV & satellite Loss Cone Imager - High Sensitivity Telescope - Fixed Sensor Head • VLF Transmitter & Receivers • Broadband receiver • Transmitter & tuning unit • Y-Axis Booms • VLF E-field Tx/Rx 8 m DC Vector Magnetometer

  10. DSXWave-Particle Interactions Payload • Receiver (Stanford, Lockheed-Martin, NASA/Goddard): • Three search coil magnetometers (3 B components) • Two dipole antennas (2 E components) • Frequency range: 100 – 50 kHz • Sensitivity 1.0e-16 V2/m2/Hz (E) & 1.0e-11 nT2/Hz (B) • Transmitter (UMass Lowell, SWRI, Lockheed-Martin): • 3 – 50 kHz at up to 500 W (900 W at end of life) • 50 – 750 kHz at 1W (local electron density) • Loss Cone Imager (Boston University, AFRL) • High Sensitivity Telescope (HST): measures 100 – 500 keV e- with 0.1 cm2-str geometric factor within 6.5 deg of loss cone • Fixed Sensor Heads (FSH): 130 deg x 10 deg of pitch angle distribution for 50 – 700 keV electrons every 167 msec • Vector Magnetometer (UCLA) • 0 – 8 Hz three-axis measurement at ±0.1 nT accuracy Transmitter control & tuning units Broadband receiver & tri-axial search coils Loss Cone Imager HST & FSH WPIx instruments designed to measure efficiency of VLF injection, propagation and wave-particle interactions in a controlled manner Vector magnetometer

  11. DSX Space Weather Payload Plasmasphere Radiation belts Ring current & aurora HEPS CEASE CEASE LCI-FSH HIPS HEPS CEASE Energy (MeV) • CEASE - Compact Environment Anomaly Sensor (Amptek, AFRL) • LEESA - Low Energy Electrostatic Analyzer (AFRL) • LIPS - Low Energy Imaging Particle Spectrometer (PSI) • HIPS - High Energy Imaging Particle Spectrometer (PSI) • HEPS - High Energy Particle Sensor (Amptek, ATC) LIPS Comprehensive SWx sensor suite will map full range of MEO space particle hazards LEESA

  12. DSXSpace Weather Effects Payload Photometers ELDRS COTS-2 CREDANCE DIME DIME SET Carrier (NASA-GSFC) • NASA Space Environment Testbed (SET) • CREDANCE (QinetiQ) • Cosmic Radiation Environment Dosimetry and Charging Experiment • DIME (Clemson Univ) • Dosimetry Intercomparison and Miniaturization • ELDRS (Arizona State) • Development of space-based test platform for the characterization of proton effects and Enhanced Low Dose Rate Sensitivity (ELDRS) in bipolar junction transistors • COTS-2 (CNES and NASA) • Validation of single event effects mitigation via fault tolerant methodology 1” Radiometers AFRL/PRS “COTS” sensors • Objective: directly measure changes in • Optical transmission, • Thermal absorption • Thermal emission • due to MEO radiation environment SFx experiments will quantify MEO environmenteffects on advanced spacecraft technologies& determine basic physics of breakdown

  13. DSXOrbital Coverage 6000 x 12000 km, 120 deg inclination Equatorial pitch-angles vs. L*

  14. DSXPlasma Environment Characteristic frequencies vs. radius Plasma density vs. radius

  15. DSXEnergetic Particle Environment > 2 MeV electrons vs. radius > 36 MeV protons vs. radius

  16. DSXLightning Climatology Satellite-Derived (LIS/OTD) MonthlyGlobal Lightning Climatology (1995 – 2003) Flashes Km-2 Year January August • Monthly global lightning climatology at 0.5 deg resolution has been developed from LIS/OTD satellite data for DSX mission planning • Model captures both cloud-to-cloud and cloud-to-ground strokes • Applications to map DSX field line footprints onto Earth’s surface being developed • “Lightning index” will computed for each ephemeris point used in mission planning

  17. Three-axis stabilized satellite with ~ 5 hour orbit SWx and SFx payloads operate continuously Momentum and power restrictions limit WPIx operations Field line tracking 1-2 hours/orbit TNT VLF high power transmission, 0.5 – 1 hour/orbit at 5 kV TNT is in passive or relaxation sounding when not in high-power VLF transmission BBR survey, LEESA, VMAG and LCI FSH are on continuously LCI HST only on in field like tracking mode LEESA high data rate mode for VLF transmission End-of-life “Hail Mary” mode for TNT VLF transmissions at 10 kV Detailed CONOPS planning underway MOC-POC-Science Data Center structure Collaboration opportunities with other assets being identified DSXCONOPS Overview

  18. DSXCollaboration Opportunities – Space 1 • Cassiope/Enhanced Polar Outflow Probe (E-PoP), CSA, CRC (James), NRL (Siefring, Bernhardt) • 300 x 1500 km, polar inclination, launch Sep 2009 • Radio Receiver Instrument (RRI), ELF-VLF 10 Hz -30 kHz, two-axis E-field • Fast Auroal Imager (FFI), ~ 1 MeV electrons • Radiation Belt Storm Probes (RBSP), NASA • 2 satellites in GTO, < 18 deg incl, launch no earlier than fall 2011 • Electric and Magnetic Field Instrument Suite and Integrated Science Suite (EMFISIS, Univ. of Iowa, Kletzing), 3 axis B-field, 2 axis E-field 10 Hz – 12 kHz (1 channel E-field 10 kHz – 400 kHz) • Magnetic Electron-Ion Spectrometer (MagEIS, BU & Aerospace, Spence & Blake), 40 keV – 10 MeV electrons • Relativistic Electron-Proton Telescope (REPT, BU & Univ. of Colorado, Spence & Baker), 2 MeV – 10 MeV electrons • RBSP Ion Composition Explorer (RBSPICE, NJIT, Lanzerotti), 25 keV – 500 keV electrons

  19. DSXCollaboration Opportunities –Space 2 • DEMETER, CNES, Stanford Co-PI (Inan) • 670 km, 98.3 deg incl, ongoing mission, will it last to 2012? • IMSC, 3 component B-field, ~ 2 Hz – 20 kHz • IDP, electron detector, ~ 50 keV – 500 keV • TRIANA, CNES, Stanford Co-PI (Inan), follow on to DEMETER • 700 km, polar, launch 2011 • IMM-MF, B-field 3 component, ~2 Hz – 20 kHz, 1 component 10 kHz – 1MHz • IDEE, electron detectors, 70 keV – 4 MeV • ORBITALS, CSA, Univ. of Calgary (Mann), Univ. of Colorado (Baker) • SCM, B-field up to 20 kHz • EPS, electrons 25 keV – 12 MeV

  20. DSXCollaboration Opportunities – Ground • High-Frequency Active Auroral Research Program (HAARP, AFRL) • Electrojet-modulated VLF antenna at L ~ 4.8 with extensive frequency & mode control • Navy VLF transmitters, RBR TIPER program (AFRL, DARPA & Stanford) • NAA at Cutler, ME, L ~ 3.0, 24 kHz, 885 kW, began keying in Jun 2008 • NWC at Churchill, Australia, L ~ 1.3, 21 kHz, 1 MW, begin keying ?

  21. DSXStatus & Summary • System CDR completed (May 2008) • #1 in 2008 DoD SERB (Nov 2008) • Payloads currently being delivered to AFRL/RV at Kirtland AFB • AI&T to be completed by Apr 2010 • DSX Science Team Meeting, 15-18 Sep 2009, Lake Arrowhead • Negotiations underway with STP for manifest as secondary payload on DMSP F-19 with launch in Oct 2012

  22. DSXNew Technologies to be Space Qualified • BBR: µLNA and µADC VLF receiver chips • LCI: RENA particle counting chip • TATU: Adaptive tuning for optimizing VLF TX • Y-Antenna: graphite epoxy material, largest compaction ratio (1:100) and best mass efficiency (35 g/m) flown to date • ESPA ring integral to host s/c bus structure • Soft-Ride Vibration Isolation – integral to s/c, not in launch stack

  23. DSXSchedule of Milestones Bus Deliveries CEASE LEESA VMAG SET-1 LCI PM Hardware Delivery Window AUG‘08 JUL’09 Avionics Module PL Deliveries Critical Path Rad/Photom Flt Battery HEPS ECS SA AM Payload Module Separation System 06/02/10 ESPA Y-Antenna Z-Antenna LIPS WIPER HIPS DSX AI&T (AFRL) TacSat-3 Last update 1/22/09

  24. DSXThe Team Space Environmental Effects PROPULSION DIRECTORATE Program Office Systems Engineering Integration and Test Launch Segment Spacecraft Bus VLF Wave-Particle Interaction Experiment Space Weather Experiments

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