Radiation Belt Storm Probes SRMDR1 Electric Fields and Waves (EFW) John Wygant EFW PI University of Minnesota

Radiation Belt Storm Probes SRMDR2 Agenda Investigation team Overview Driving requirements Science compliance Primary measurement requirements Design description Interface definition Heritage Technology development plan Resource summary Operations concept Verification & validation Risks & mitigation Phase B plans Star Tracker RP-Spice RPS Hope REPT Shunts (4x) Magnetometer Boom Axial Boom (aft) 1 of 2 RF Antenna (aft) Louvers Battery Radiator DSAD (2x) SP Wire Boom (4x) MagEIS (4x) - [Low, Medium (2x), High]

Radiation Belt Storm Probes SRMDR3 Investigation Team Financial Mgr K. Harps, UCB Financial Mgr K. Harps, UCB RBSP EFW PI J. Wygant, UM RBSP EFW PI J. Wygant, UM PM/SE P. Harvey, UCB PM/SE P. Harvey, UCB Science Co-I’s Subcontracts J. Keenan, UCB Subcontracts J. Keenan, UCB QA R. Jackson, UCB QA R. Jackson, UCB Lead Electrical M. Ludlam Lead Electrical M. Ludlam Lead Mechanical P. Turin Lead Mechanical P. Turin Sensors J. Bonnell Sensors J. Bonnell Signal Processor R Ergun, LASP Signal Processor R Ergun, LASP Ground Systems M. Hashii Ground Systems M. Hashii Analog: H. Richard Digital: M. Ludlam FSW: P. Harvey LVPS: P. Berg AXB: R. Duck SPB: G. Dalton Dynamics: D. Pankow Lead : J. Westfall

Radiation Belt Storm Probes SRMDR4 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 Main electronic box (filtering, A-D conversion, sensor bias control, burst memory, diagnostics, mode commanding, TM formatting ) 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 potential across spacecraft surfaces smaller than 1 Volt.

Radiation Belt Storm Probes SRMDR5 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

Radiation Belt Storm Probes SRMDR6 Science Compliance EFWRBSP Science Objective X 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. X 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. X quantify the processes that lead to the formation and subsequent decay of transient radiation belt structures. X quantify the relative contribution of adiabatic and non-adiabatic processes on the acceleration, transport, and loss of energetic particles X determine the role of "seed" or source populations for relativistic particles. X quantify the effects of the ring current and related storm phenomena on relativistic particles X quantify how and why the ring current and associated phenomena vary during storms X use the science understanding to improve and validate physics-based data assimilation and specification models for the Earth’s radiation belts

Radiation Belt Storm Probes SRMDR7 Science Compliance

Radiation Belt Storm Probes SRMDR8 Primary Measurement Requirements

Radiation Belt Storm Probes SRMDR9 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: 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.

Radiation Belt Storm Probes SRMDR10 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

Radiation Belt Storm Probes SRMDR11 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

Radiation Belt Storm Probes SRMDR12 Flight Software Description  Development Plan : RBSP_EFW_SW_001  Requirements: NPR V. Sep 27, 2004  Heritage : CRRES, Polar, Cluster, THEMIS  Language: 8085  Functional Requirements: ~200  Effort : ~10000 SLOC in 22 modules  Test Platform: ETU  Phases: 1.Board, 2.Box, 3.Inst, 4.Autonomy  Management: Resource Track, Req’s Met  Quality : Integrated with Flight Development  Major Functional Elements:  Command Reception & Distribution  Real-Time Data Collection and Playback  On-Board Evaluation for Burst Triggering  Burst Data Collection and Playback  Sine-Wave Fits of E-Field Signal  Delta Mod Compression  Boom Deployment Control

Radiation Belt Storm Probes SRMDR13 Interface Definition IDPU SPB1 SPB2 SPB4 SPB3 AXB2 AXB1 EMFISIS COMMANDS TELEM MAIN +28V SPB Power AXB Power X-Axis Y-Axis Z-Axis EFW X,Y,Z MAG X,Y,Z SCM X,Y,Z

Radiation Belt Storm Probes SRMDR14 Heritage Spacecraft SPB’s AXB’s S3-2 4 S ISEE 2 VIKING 4 FREJA 6 FIREWHEEL* 2 CRRES 2 POLAR 4 FAST 4 2 CLUSTER I*16 CLUSTER II16 THEMIS2010 SPARES26 6 Lunar Prospector Sounding Rockets ~ * LV did not achieve orbit

Radiation Belt Storm Probes SRMDR15 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.

Radiation Belt Storm Probes SRMDR16 Resource Summary CBE (NTE) Mass: 21.3 (23.6) kg Power: 7.8 (8.6) W Telemetry rate: 16.5 (16.5) kbit/sec

Radiation Belt Storm Probes SRMDR17 Operations Concept Commissioning –Draft Deployment Sequence Delivered to APL –Sequence takes approx 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 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

Radiation Belt Storm Probes SRMDR18 Instrument Verification & Validation Plan EFW Verification Plan (RBSP_EFW_SYS_300) Unit Mass Props CPTDeployEMCMAGVibTVACCalibration Preamp √√√ Sensor √√√ SPB √√√√√√ AXB √√√√√√ IDPU √√√√√√√ EFW Inst. √√√√√

Radiation Belt Storm Probes SRMDR19 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 Fields Phasing EMC Electrostatic Cleanliness Func Test CommandingCompatibility EFW - Space craft √√√√√ EFW - EMFISIS √√√

Radiation Belt Storm Probes SRMDR20 Risks and Mitigation LIKELIHOODLIKELIHOOD CONSEQUENCES Approach M – Mitigate W – Watch A – Accept R - Research * Criticality Decreasing (Improving) Increasing (Worsening) Unchanged New since last month L x C Trend    Med High Low

Radiation Belt Storm Probes SRMDR21 Risks and Mitigation

Radiation Belt Storm Probes SRMDR22 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)