RBSP_EFW_RMDR_071002D

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					Electric Fields and Waves
           (EFW)

        John Wygant
           EFW PI
   University of Minnesota




       RBSP RMDR 2-4 October 2007   1
Agenda
   Investigation team
   Overview
   Driving requirements                             Hope
   Science compliance             Magnetometer Boom            RP-Spice
   Primary                       Star Tracker
    measurement
    requirements
   Design description RF Antenna
   Interface definition        (aft)
   Heritage
   Changes since MCR Shunts (4x)
   Technology              Louvers
    development plan
   Resource summary
   Operations concept                                                        MagEIS (4x)
                                                                              - [Low, Medium (2x),
   Verification &                                                            High]
    validation
   Risks & mitigation                                                  Axial Boom (aft)
   Phase B plans        SP Wire Boom (4x)                                    1 of 2
                                           RPS                    Battery Radiator
                                                                DSAD (2x)
                                                         REPT

                            RBSP RMDR 2-4 October 2007                            2
Investigation Team
                                                    RBSP EFW PI
                                                    J. Wygant, UM


                                                       PM/SE                 Science Co-I’s
                                                    P. Harvey, UCB


               Financial Mgr           Subcontracts                                        QA
               K. Harps, UCB          J. Keenan, UCB                                R. Jackson, UCB



Lead Mechanical         Lead Electrical                 Sensors      Signal Processor        Ground Systems

    P. Turin              M. Ludlam                    J. Bonnell    R Ergun, LASP              M. Hashii


    AXB: R. Duck               Analog: H. Richard                      Lead : J. Westfall
    SPB: G. Dalton             Digital: M. Ludlam
    Dynamics:                  FSW: P. Harvey
        D. Pankow              LVPS: P. Berg




                                     RBSP RMDR 2-4 October 2007                                             3
 Overview
RBSP Electric Field Waves Features
Four spin plane booms (2 x 40 m and 2x 50 m)
Two spin axis stacer booms (2x6 m)
Spherical sensors and preamplifiers near outboard tip of boom (400 kHz response)
Flexible boom cable to power sensor electronics & return signals back to SC
Sensors are current biased by instrument command to be within ~ 1 volt of ambient
plasma potential.           1        Main electronic box (filtering, A-D conversion,
                                     sensor bias control, burst memory, diagnostics,
                                     mode commanding, TM formatting )
4
                          5           EFW Science quantities include:
                                         • E-fields:(V1-V2, V3-V4, V5-V6)
                                         •Interferometric timing: SC-sensor potential
                                         (V1s, V2s, V3s, V4s, V5s, V6s)
                                         •SC Potential : (V1+V2)/2, (V3+V4)/2

                                      Interface to EMFISIS instrument
                                      Electrostatic cleanliness spec: variations of
6                                     potential across spacecraft surfaces smaller than
                                  3   1 Volt.
                              RBSP RMDR 2-4 October 2007                            4
    2
 Overview
 Science Objective: Measure electric fields associated with a variety of
  mechanisms causing particle energization, scattering and transport in the
  inner magnetosphere.

 These mechanisms include:
   Energization by the large-scale convection E-field .
   Energization by substorm injection fronts propagating in from the tail.
   Radial diffusion of energetic particles mediated by ULF MHD waves.
   Transport and energization by intense magnetosonic waves generated
    by interplanetary shock impacts upon the magnetosphere.
   Coherent and Stochastic acceleration and scattering of particles by
    small-scale, large-amplitude plasma structures, turbulence and waves
    (EM and ES ion cyclotron waves, kinetic Alfven waves, lower hybrid,
    small scale magnetosonic waves,solitary waves, other non-linear
    structures)
 EFW measurements address all 8 of the RBSP science goals with a lesser
  contribution to goal 6


                         RBSP RMDR 2-4 October 2007                        5
  Science Compliance
EFW Science Objective
    1) identify the processes responsible for the acceleration and transport of
    relativistic and near-relativistic particles, determine when and where these
    processes occur, and determine their relative significance
    2) identify the processes responsible for the precipitation and loss of relativistic
    and near relativistic particles, determine when and where these processes
    occur, and determine their relative significance.

      3) quantify the processes that lead to the formation and subsequent decay of
      transient radiation belt structures.
      4) quantify the relative contribution of adiabatic and non-adiabatic processes on
      the acceleration, transport, and loss of energetic particles

      5) determine the role of "seed" or source populations for relativistic particles.

      6) quantify the effects of the ring current and related storm phenomena on
      relativistic particles
      7) quantify how and why the ring current and associated phenomena vary
      during storms
      8) use the science understanding to improve and validate physics-based data
                                                            s
      assimilation and specification models for the EarthÕ radiation belts


                            RBSP RMDR 2-4 October 2007                                    6
  Science Compliance
Science Mechanism/            Dura-        E-Field E-field         Cold            Interfer-
Goals   Structures            tion        (Spin    (Spin           density         ometric
                                          plane)* axis)*           (SC pot)        timing
1, 3,4,8    Interpl anetary   1-300 s     1 -300     2 -300        1-50 cm-3       NA
            shock i mpact                 mV/m       mV/m          (n/n<50%)

1, 4, 6,8   Injecti on events 5-600 s     1- 300     2-300         1-50cm 3        NA
                                          mV/m       mV/m          (n/n<50%)

4, 6, 7,8   Convection        300 -    0.3-15        2-15          NA              NA
            electric field    36,000 s mV/m          mV/m

1, 4, 6,8    MHD wave         10-600s     1- 40      2- 40         1- 50 cm-3      NA
             driven radial                mV/m       mV/m          (n/n<50%)
             diffusi on
1, 2, 3,    Small scale/      5 ms-       0.1-300    2-300         1- 50 cm-3      Timing:
4, 5, 8     large             5s          mV/m       mV/m                          0.06 ms
            amplitu de                                             (n/n<50%)      Velocit y:
            structur es:                                                           0-500 km/s
2, 4, 5,8    Plasmapause NA                   NA           NA         1- 50 cm-3    NA
             densit y profile                                         (n/n<50%)
* Sensiti vity for spin pla ne electric fiel d larger of 0.3 mV/m or 10% o f magnitude; f or spin axis lar ger of 2 mV/m
or 10% of magnitude ; For small scal e structures se nsitivity is larger of 0.1 mV/m o r 10%of magni tude.


                                        RBSP RMDR 2-4 October 2007                                                   7
     Primary Measurement Requirements
Measurement             Dynamic       Sensitivity                         Frequency      Req:       Difficulty
                        Range                                             Range/Timing   MRD ELE
Spin Plane              0.3-300       > 0.3 mV/m or 10% of signal for     15 Hz          128        Medium
Electric Field          mV/m          R>2.5 Re

Spin Axis               2-300 mV/m    > 2 mV/m or 10% of signal for       15 Hz          172        Medium
Electric Field                        R>2.5 Re

Cold Plasma             0.1 -50       n/n ~50%                           0.5 Hz         134        Easy
Density (<30eV)          cm-3
 Small        3d        0.3-300       0.05 mV/m                           200 Hz         157,162,   Easy
Scale         E-field   mV/m          10-13 V2/m2 Hz @ 1 kHz                             172,177
Large
Amplitude     3dB       90 dB         0.3 pT

Structures    n        0-50 cm-3     n/n ~10%

Interferometric         0-500 km/s    NA                                  0.06 ms        167        Easy
Timing                  (0.1-30km)

 EMFISIS Interface      90 dB (TBR)   Spin plane:                         10 Hz-400 Hz   126        Medium
3 D Wave E-field                      3x10-14 V2/m2Hz @ 1 kHz (TBR)
                                      3 x 10-15V2/m2Hz
                                       @ 100 kHz (TBR)
                                      (Spin axis x 10 less ) sensitive)




                                        RBSP RMDR 2-4 October 2007                                               8
SPB Description
         Mass: 2.20 kg/unit (4 total).
         Envelope: 9.9”H x 4.6”W x 8.6”D.
         Deployed Length: 80/100 m tip-to-tip.
             (47 m cable + 3 m fine wire in each SPB.)
         Deploy Rate: 0.5-1.0 cm/s.
         Cable Mass Rate: ~3 g/m.
         Fine Wire Mass Rate: < 1 g/m.
         Preamp Mass: 48 g (up to 150 g w/up-shield and cable driver).
         Sphere/Keyreel Mass: 100 g.
         Deployed spin MOI: 1920 kg-m2 total
         Power: 2.6 W/unit (typ., deploy motor only).
         Actuators: Doors are spring-loaded, SMA-released; Cable
        deploy is motor-driven; no pyros required for actuation.




             RBSP RMDR 2-4 October 2007                         9
AXB Description
      Mass: 6.21 kg total (2 booms + tube).
      Footprint: 26” H x 6.400” OD inches.
      Deployed Length: 13m tip-to-tip.
      0.5-m whip sensor stacer.
      Power: 35 W max per boom for release
      Actuators: Frangibolt sphere release, main boom release.
      Deployment is motor-driven




     Flight Axial Tube & one AXB from THEMIS

                 RBSP RMDR 2-4 October 2007                       10
IDPU Description
            Mass: 4.6 kg.
            Dimensions: 9.75H x 4.7W x 7.95D inches
            Power: 7.8 W CBE.
            Elements and Function:
               • Chassis – provides structural and rad shielding
               • Backplane – signal and power distribution.
               • Low-Voltage Power Supply (LVPS) - conversion
               • Power Controller Board (PCB) – switching
               • Data Controller Board (DCB) – cmd & telem
               • Solid State Recorder - data storage
               • Boom Electronics Board (BEB) – sensor control.
               • Digital Fields Board (DFB) –signal processing.
               • EMFISIS Interface – buffering of E & B signals




           RBSP RMDR 2-4 October 2007                       11
  Flight Software Description
CSC#
   1
        Function
        Executive
                               Name
                               EXEC
                                            Development Plan : RBSP_EFW_SW_001
   2    Background             BKG          Heritage : CRRES, Polar, Cluster, THEMIS
   3    Commands               CMD
   4    Telemetry              TM           Language: 8085 (Harris RH)
   5
   6
        Housekeeping
        Loader
                               HSK
                               LD
                                            Requirements: ~200
   7
   8
        Utilities
        Input/Output
                               UTIL
                               IO
                                            Effort : ~10000 SLOC in 22 modules
   9    Power Manager          PWR          Test Platform: ETU
   10   SSR Manager            SSR
   11   ACS                    ACS          Phases: Board, Box, Inst, Autonomy
   12
   13
        EFW Manager
        FGM Manager
                               EFW
                               FGM
                                            Quality : Integrated with Flight Development
   14
   15
        EFW Deployment
        EEPROM Installer
                               DEP
                               EEP
                                            Major Functional Elements:
   16   EFW/FGM Fit Manager    FIT              Command Reception & Distribution
   17   Spin Fit Calculator    SPIN
   18   Matrix Solver          MATRIX           Real-Time Data Collection and Playback
   19
   20
        Trigonometrics
        Fast Floating Point
                               TRIG
                               FFP
                                                On-Board Evaluation for Burst Triggering
   21
   22
        Compression Algs
        Science Optimization
                               CMP
                               SCI
                                                Burst Data Collection and Playback
                                                Sine-Wave Fits of E-Field Signal
                                                Delta Mod Compression
                                                Boom Deployment Control




                                        RBSP RMDR 2-4 October 2007                 12
Interface Definition

     SPB1          X-Axis


     SPB2
                                                      COMMANDS

     SPB3          Y-Axis             IDPU             TELEM


     SPB4                                             MAIN +28V

                                                       SPB Power
     AXB1          Z-Axis
                              EFW     MAG     SCM      AXB Power
                              X,Y,Z   X,Y,Z   X,Y,Z
     AXB2




                                 EMFISIS




            RBSP RMDR 2-4 October 2007                             13
   Heritage
Spacecraft         SPB’s        AXB’s   Mag Booms
  S3-2               4
  S3-3               4           2
  ISEE               2
  VIKING             4
  FREJA              6
  FIREWHEEL*         2
  CRRES              2
  POLAR                          4         2
  FAST               4           2         2
  CLUSTER I*       16
  CLUSTER II       16
  THEMIS           20           10       10
   SPARES          26            6        2
  Lunar Prospector                        1
  Sounding Rockets             ~50
                  -----        -----    -----
                 110         26-76        15

* LV did not achieve orbit



                               RBSP RMDR 2-4 October 2007   14
 Major Changes Since MCR
 AXB Booms Aligned on Center
 AXB Deployed DAD Section is Below Antenna
 AXB Sensor Folding Rigid Section (Whip)
 AXB Motor Drive for On-Orbit Adjustable Lenth
 IDPU Higher Data Allocation
 IDPU Added Internal Foldback Limits (Redundant E-Fields)




                    RBSP RMDR 2-4 October 2007               15
New Development Items
 Boom Deployment Systems
  Units based on ISEE, CRRES, Polar, FAST, Cluster-II, and
   THEMIS heritage.
  Changes will include thinner cable, using SPB-type motor type for
   AXB instead of brake.

 Sensor Electronics (Preamp and BEB)
  Units are based on Polar, Cluster-II, and THEMIS heritage.
  Changes will include thinner cable, possible cable driver.

 IDPU Power, DSP, DPU, and Burst Memory
  Units are based on Polar, FAST and THEMIS heritage.
  Changes will include interfaces to other instruments and SC,
    adjustments to filter frequencies and ADC rates, flight software
    changes.

                     RBSP RMDR 2-4 October 2007                  16
Resource Summary
                                        CBE (NTE)
 Mass: 21.3 (23.6) kg
 Power: 7.8 (8.6) W
 Telemetry rate: 16.5 (16.5) kbit/sec
                                                             CBE
                           Unit         CBE       Rad                                            %          NTE
                                                             Mass           Maturity
     Component   #         Mass         Mass     Shield                                        Growth       Mass
                                                           w/Shield          Level
                           (kg)         (kg)      (kg)                                          AGM         (kg)
                                                             (kg)
SPB-1            1          2.20         2.20       0.00     2.20     Mod of existing design    10%         2.42
SPB-2            1          2.20         2.20       0.00     2.20     Mod of existing design    10%         2.42
SPB-3            1          2.20         2.20       0.00     2.20     Mod of existing design    10%         2.42
SPB-4            1          2.20         2.20       0.00     2.20     Mod of existing design    10%         2.42
AXB-1            1          2.81         2.89       0.03     2.92     Mod of existing design     9%         3.19
AXB-2            1          2.81         2.89       0.03     2.92     Mod of existing design     9%         3.19
AXB Tube Assy    1          0.60         0.60       0.00     0.60     Mod of existing design    10%         0.66
IDPU             1          3.62         3.62       1.00     4.63      New Development          13%         5.24
Harness          1          1.94         1.94       0.06     2.00      New Development          15%         2.30
EFW TOTAL                  19.97        20.13       1.12    21.25                               11%         23.58

                                                                                       Daily             Weekly
                             Power (W)                                     Average
     Component                                              Category                Allocation          Allocation
                                                                          Data Rate
                     CBE       Margin      NTE                                        Gbits               Gbits
 BOOMS                0.48      5.0%         0.50          Real Time         2.14      0.19                1.30
 IDPU                 7.33     10.2%         8.08          Playback         14.36      1.24                8.68
 EFW TOTAL           7.812      10%         8.584          Total            16.50      1.43                9.98



                                RBSP RMDR 2-4 October 2007                                                          17
  Operations Concept
 Commissioning
   Draft Deployment Sequence Delivered to APL
   Sequence takes appx 2 weeks including science diagnostics
   Z-axis adjustment operations are to be decided
 Normal operations
   Constant Real-Time Data Streaming
   Playback of stored events
 Bursting
   Automatic detection of interesting events
   Burst Flag sent to S/C
   S/C directed burst events
 Command and data handling
   Commands determined and sent from UCB
   Telemetry distribution at UCB
   SOH determination at UCB

 SOC Operations will be run from UC Berkeley




                        RBSP RMDR 2-4 October 2007              18
Instrument Verification & Validation Plan

EFW Verification Plan (RBSP_EFW_SYS_300)

            Mass
Unit                CPT    Deploy     EMC     MAG     Vib   TVAC   Calibration
            Props

Preamp       √      √                                        √
Sensor       √      √                                                  √
SPB          √      √         √                   √   √      √

AXB          √      √         √                   √   √      √

IDPU         √      √         √                   √   √      √         √


EFW Inst.           √         √        √                     √         √



                     RBSP RMDR 2-4 October 2007                          19
 S/C Level Instrument V & V Plan
EFW Will Support APL’s Verification of Spacecraft
EFW Flow Will be as Simple as Possible
Expect “Bolt-Hole” Alignments are Sufficient for Boom Systems
EFW-EMFISIS Verification Expected to Require Boom Deployment
Deployment of Spin Plane Booms and +Z Axial Sensor is Practical at I&T

                                                             Func Test
              Fields               Electrostatic
                          EMC
             Phasing               Cleanliness       Commanding   Compatibility
   EFW -
   Space        √          √             √               √               √
    craft
  EFW -
 EMFISIS        √          √                                             √




                        RBSP RMDR 2-4 October 2007                       20
        Risks and Mitigation
    5                                                   Chg RANK   ID    Approach             TITLE
L
                                                             1     E-1   Mitigate EFW-EMFISIS Signal Noise
I
K   4
E                                                        *   2     E-5   Mitigate AXB Shadowing
L
I   3
                                                             3     E-2   Mitigate Thin Wire Qualification
H
O                   4      1 5
O   2                                                    *   4     E-4   Mitigate BEB High Voltage
D
                    3               2
    1                                                    -   5     E-3   Mitigate AXB Sensor Qualification

            1      2        3        4        5
                 CONSEQUENCES

        Criticality L x C Trend               Approach
          High      Decreasing (Improving)   M – Mitigate
                    Increasing (Worsening)   W – Watch
                    Unchanged                A – Accept
          Med
                    * New since last month    R - Research
          Low


                                         RBSP RMDR 2-4 October 2007                                         21
Risks and Mitigation
ID        Title       P   I   Crit Risk Statement              Impact             Plan
                                 If EFW signal noise above     Delay for redesign Develop MOU and ICD for
                                 EMFISIS requirement,                             proper grounding and
      EFW-EMFISIS
E-1                   2   3    L then sensor and/or                               shielding
      Signal Noise
                                 electronics need redesign.                       Test the performance early

                                 If Thin Wire does not qualify, Major impact to   Advance mech and elect
                                 then the EFW will have         spacecraft fuel   tests, including strength,
       Thin Wire
E-2                   1   4    L larger MOI and the S/C will                      CTE and noise
      Qualification
                                 need more fuel                                   performance.

                                 If AXB sensor does not        Delay for redesign Prototype mechanical
                                 qualify,                                         device to be built in phase
      AXB Sensor
E-3                   1   2    L then there may be schedule                       A.
      Qualification
                                 delays in developing the
                                 instrument.
                                 If Boom Electronics Board     Cost impact for    Widen search for high
                                 cannot make 250V using        redesign.          voltage PNP and NPN.
       BEB High
E-4                   2   2    L drop in parts,                Mass increase of   Verify requirement of 250
        Voltage
                                 then BEB will grow.           1kg                is really necessary.

                                 If instrument shadows affect Degrade science Investigate using a data
                                 EFW -Z sensor,                               analysis mask to remove
         AXB
E-5                   2   3    L then it may be difficult to                  noise points
      Shadowing
                                 measure electric fields with
                                 axial sensors.

                                    RBSP RMDR 2-4 October 2007                                                  22
 Phase B Plans
Activities
     06/08 EFW Instrument Requirements Review
     09/08 EFW Instrument Preliminary Design Review
     09/08 EFW SOC Preliminary Design Review
     11/08 Support MPDR

     01/09 SPB ETU Design, Fab & Test
     01/09 AXB ETU Design, Fab & Test
     12/08 IDPU ETU Design, Fab
     12/08 Harness ETU Design, Fabrication
     12/08 S/C – EFW Interface Test (Emulator)




                       RBSP RMDR 2-4 October 2007     23

				
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