THEMIS MISSION CDR ESA-1 UCB, June 14 - 18 2004

THEMISTIME HISTORY OF EVENTS AND MACROSCALE INTERACTIONS DURING SUBSTORMS

RESOLVING THE MYSTERY OF WHERE, WHEN AND HOW AURORAL ERUPTIONS START

THEMIS Mission Critical Design Review – ESATHEMIS Mission Critical Design Review – ESAJune 14 – 18, 2004June 14 – 18, 2004University of California, BerkeleyUniversity of California, Berkeley

THEMIS MISSION CDR ESA-2 UCB, June 14 - 18 2004

ESA Plasma InstrumentMission CDR

Dr. C. W. Carlson and THEMIS ESA TeamUC Berkeley SSL

THEMIS MISSION CDR ESA-3 UCB, June 14 - 18 2004

Overview

ESA Plasma Instrument

• Requirements & Specifications

• Heritage

• Design Overview

• Block Diagram

• Component Descriptions

• Mechanical

• Test and Calibration

THEMIS MISSION CDR ESA-4 UCB, June 14 - 18 2004

Requirements and Specifications

Measurement

• The ESA instrument measures 3-D electron and ion energy distribution functions over the Energy range 10 eV to 30 keV. Typical energy sweep has 16 or 32 energy samples

• A full 4-pi distribution measurement is produced during each spin

• Sweep rate of 32/spin gives dense sample of 3-D particle distributions

• Raw measurements are compressed to selectable “reduced distributions” and moments

Implementation

• Ion and electron “top-hat” electrostatic analyzers have 180 degree field of view

• Field of view is divided into 8 electron and 16 ion elevation bins

• Plasma analyzers have hardware programmed functions: sweep rate, sweep waveform, energy range, data collection rates. These functions are set by command.

• Higher level data formatting and computed products are carried out in the ETC board. Energy sweep is exponential with programmable starting energy and step ratio

THEMIS MISSION CDR ESA-5 UCB, June 14 - 18 2004

Heritage

ESA Instrument Design is based on FAST plasma instrument

• Nearly identical measurement requirements

• Well proven design – all 16 FAST ESA detectors remain fully functional after 7 years in orbit (Design requirement was 3 years in high radiation environment)

• Flight hardware designs and calibration facilities can be used with minor changes

• The only major electronics design change is to upgrade from the ACTEL 1020 gate arrays to the ACTEL RT54SX72S. This reduces the number of components required and makes the design consistent with other THEMIS instruments.

• THEMIS instrument uses the FAST strategy of “dumb” sensors having hardware defined measurement modes, combined with a “smart” processor-based interface board that performs data formatting and higher level computations. The ETC board provides this intermediate processing for both the ESA and SST.

THEMIS MISSION CDR ESA-6 UCB, June 14 - 18 2004

REQUIREMENT ESA DESIGN

IN-1. The Instrument Payload shall be designed for at least a two-year lifetime

Compliance. Lifetime has been considered in all aspects of ESA Design. System design and components are direct copy of FAST ESA (still fully functional after 7 years on orbit)

IN-2. The Instrument Payload shall be designed for a total dose environment of 33 card/year

(66 krad for 2 year mission, 5mm of Al, RDM 2)

Compliance. Common Parts buy for Instrument Payload. Lower radiation dose than FAST ESA has experienced without problem.

IN-3. The Instrument Payload shall be Single Event Effect (SEE) tolerant and immune to destructive latch-up

Compliance. FAST components were selected for SEE and latch-up immunity and are verified by flight history.

IN-7. No component of the Instrument Payload shall exceed the allocated mass budget in THM-SYS-008 THEMIS System Mass Budget.xls

Compliance. 2.84 kg Allocated. This allocation will be met. As built mass for the equivalent FAST instrument is 1.92 kg. Radiation Shielding accounts for the additional mass.

IN-9. No component of the Instrument Payload shall exceed the power allocated in THM-SYS-009 THEMIS System Power Budget.xls

Compliance. 2.00 W Allocated. As built power for equivalent FAST instrument is 1.75 Watt.

IN-13. The Instrument Payload shall survive the temperature ranges provided in the ICDs

Compliance. ESA is designed and will be tested to comply with the ICD requirements.

IN-14. The Instrument Payload shall perform as designed within the temperature ranges provided in the ICDs

Compliance. ESA is designed and will be tested to comply with the ICD requirements.

Mission Requirements

THEMIS MISSION CDR ESA-7 UCB, June 14 - 18 2004

REQUIREMENT ESA DESIGN

IN-16 The Instrument Payload shall comply with the Magnetics Cleanliness standard described in the THEMIS Magnetics Control Plan

Compliance. THM-SYS-002 Magnetics Contamination Control Plan.

IN-17 The Instrument Payload shall comply with the THEMIS Electrostatic Cleanliness Plan

Compliance. THM-SYS-003 Electrostatic Cleanliness Plan

IN-18 The Instrument Payload shall comply with the THEMIS Contamination Control Plan

Compliance. THM-SYS-004 Contamination Control Plan

IN-19. All Instruments shall comply with all electrical specifications

Compliance. THM-IDPU-001 Backplane Specification.

IN-20. The Instrument Payload shall be compatible per IDPU-Instrument ICDs

Compliance. THM-SYS-105 ESA and SST Electronics Card (ETC) Specification. Verification Matrices to be completed.

IN-21. The Instrument Payload shall be compatible per the IDPU-Probe Bus ICD

Compliance. THM-SYS-101 IDPU/ESA-to-Probe ICD. Verification Matrices to be completed.

IN-23 The Instrument Payload shall verify performance requirements are met per the THEMIS Verification Plan and Environmental Test Spec.

Compliance. THM-SYS-005 Verification Plan and Environmental Test Specification preliminary draft. Verification matrix to be completed.

IN-24 The Instrument Payload shall survive and function prior, during and after exposure to the environments described in the THEMIS Verification Plan and Environmental Test Specification

Compliance. THM-SYS-005 Verification Plan and Environmental Test Specification preliminary draft. Verification matrix to be completed.

Mission Requirements

THEMIS MISSION CDR ESA-8 UCB, June 14 - 18 2004

REQUIREMENT ESA DESIGN

IN.ESA-1. The ESA shall obtain partial moments of the 3D plasma electron and ion distributions in the magnetotail plasma sheet

Compliance. ESA will provide the ETC board with plasma measurement data sufficient for computing the required moments.

IN.ESA-2. The ESA shall measure differences in velocity and ion pressure between probes in the magnetotail plasma sheet

Compliance. ESA will provide the ETC board with plasma measurement data sufficient for computing the required moments.

IN.ESA-3. The ESA shall measure ion and electron distributions that are associated with the current disruption process

Compliance. ESA will provide the ETC board with plasma measurement data sufficient for computing the required moments.

IN.ESA-4. The ESA shall be capable of measuring ion moments and differences of those moments in the magnetosheath and solar wind.

Compliance. ESA will provide the ETC board with plasma measurement data sufficient for computing the required moments. Solar wind moments will be limited to a specific range of velocity and density consistent with instrument saturation.

Science Requirements

THEMIS MISSION CDR ESA-9 UCB, June 14 - 18 2004

REQUIREMENT ESA DESIGN

IN.ESA-5. The ESA shall measure ions and electrons over an energy range of 10eV to 30 keV

Compliance. Satisfied by design.

IN.ESA-6. The ESA energy sampling resolution, dE/E, shall be better than 25% FWHM for ions and electrons

Compliance. Satisfied by design.

IN.ESA-7. The ESA shall be capable of measuring ion and electron energy flux of 10^4 to 10^9 keV/cm^2/s/Str/keV

Compliance. Satisfied by design.

IN.ESA-8. The ion ESA geometric factor shall be attenuated in the solar wind to avoid saturation.

Compliance. High fluxes of solar wind ions will be accommodated by small area anodes in the equatorial view directions.

IN.ESA-9. The ESA shall supply partial energy moments at one spin time resolution.

Compliance. Satisfied by design.

IN.ESA-10. The ESA shall have a 180 deg. elevation FOV with a minimum angular resolution of 22.5 deg.

Compliance. Satisfied by design.

IN.ESA-11. To resolve the solar wind, the ESA shall have a FOV with enhanced resolution of ~ 6 deg.

Compliance. Satisfied by design.

IN.ESA-12. The ESA shall produce measurements of particle distributions over the entire 4pi steradian field of view in one spin period.

Compliance. Satisfied by design.

IN.ESA-13. ESA calibration shall ensure <20% relative flux uncertainty (not including statistical uncertainty) over the ranges defined above.

Compliance. Satisfied by on-orbit calibration of plasma density with wave measurements.

Performance Requirements

THEMIS MISSION CDR ESA-10 UCB, June 14 - 18 2004

ESA Development Team

ESA Systems• Definition and Specifications: Charles Carlson• Mechanical: Bill Elliott, Paul Turin• Analog and Digital Systems: Charles Carlson, Mike Ludlam• IDPU Instrument Interface: Robert Abiad• Flight Software: Frank Harvey• Fabrication and Parts Management: Chris Scholz• Thermal: Chris Smith• MCP Testing: Mario Marckwordt, Jeff Hull• Calibration and Test Facilities: Mario Marckwordt• Ground Support Equipment: Jim Lewis• Spacecraft Integration & Test Requirements: Bill Elliott

ESA Support Functions• Probe Interfaces: Ellen Taylor• Reliability and Quality Assurance (R&QA): Ron Jackson• Parts Engineering: Jorg Fischer

THEMIS MISSION CDR ESA-11 UCB, June 14 - 18 2004

Design Overview

THEMIS Uses FAST ESA Design(1/2 of a FAST module)

• Modular for efficient testing, assembly and repair

• Entrance sealed and nitrogen purged

• Outstanding operational performance

Specifications:• 180 degree elevation field of view

with a minimum angular resolution of 22.5 degrees.

• To resolve the solar wind the IESA will have a field of view with enhanced resolution of approximately 5.62 degrees.

Pulse Amplifiers

Digital Interface

& HV Sweep

HV Supplies

}

MCP

THEMIS MISSION CDR ESA-12 UCB, June 14 - 18 2004

THEMIS ESA

Simplified View of the new THEMIS ESA mechanical design illustrating design changes.

Changes from FAST• Ion Detector Anode pattern

• Cover Release Mechanism (SMA Actuator)

• Upgrade ACTEL Gate Arrays to RT54SX72S

• HV Supplies repackaged in pairs

• Higher density ACTELs on Preamp Board and

Main Interface Board

THEMIS MISSION CDR ESA-13 UCB, June 14 - 18 2004

Block Diagram

• Electronics functional design is identical to FAST (with ACTEL upgrades)• Three circuit modules plug together for efficient assembly and test• MCP pulse amplifiers are Amptek A121 with programmable gain• All discrete logic, counters, and HV DAC drivers are Actel FPGAs• HV & LV supplies are mature designs built at UCB SSL

THEMIS MISSION CDR ESA-14 UCB, June 14 - 18 2004

Analyzer/Anode/Preamp

FAST ESA module

Themis uses FAST module design

• IESA/EESA Analyzers Analyzer deflection plates Aperture closer mechanism UV rejection Cu-Black coating Nitrogen purge system

• Anode Boards Mounts MCPs HV Interface connectors HV coupling capacitors

• Preamp Board AMPTEK A121 preamps Actel logic arrays Anode and Logic board interfaces

THEMIS MISSION CDR ESA-15 UCB, June 14 - 18 2004

MCP/Anode Board Assembly

Top Bottom

Anode boards includes:

• MCP Mounting Hardware “Spring finger” clamp rings HV electrode connections Nitrogen purge plumbing

•HV InterfaceHV Plugs and wiring HV filter capacitors Bias resistor

• Preamp Interface Limit resistors & clamp diodes Preamp interface connector

• Materials Polyimide / glass PCB PEEK mounting rings KAPTON spacers Gold plated Be Cu springs 16 Anode 8 Anode

THEMIS MISSION CDR ESA-16 UCB, June 14 - 18 2004

MCP Preamp/Accumulator

Preamp board includes:

• 24 AMPTEK A121 hybrid preamps

• ACTEL Gate array contains:

24 x 14 bit accumulators

Command/Data Interface

Command interpreter

Test pulse generator

Preamp gain control DAC driver

Commandable selective anode blocking

• MCP Anode board interface

• Radiation “spot shielding” for preamps

THEMIS MISSION CDR ESA-17 UCB, June 14 - 18 2004

HV Sweep & Digital Interface

HV Sweep/ Interface board includes:

• Main data interface to ETC board and IDPU power board

• HV fixed and sweep supply control

• HV Sweep waveform generator (Amptek HV-601 high voltage optocouplers)

• Housekeeping multiplexer

• Plug-in interface to anodes and HV supplies

Modified FAST Sweep/Interface Board

Themis board is about 30 % shorter length

THEMIS MISSION CDR ESA-18 UCB, June 14 - 18 2004

FAST HV Supply Assembly

FAST HV Interface Board

(mounts on back side of Sweep/Interface board)

Themis board is about 30 % shorter length

HV Assembly board includes:

• Four HV supplies with interface mother board (FAST example has 6 supplies)

• Supplies are packaged as a pair of dual supplies.

• HV supply assembly and Digital interface boards share structural mount plate

• HV supplies have HV sockets that mate directly with HV plugs on HV sweep board and on anodes.

THEMIS MISSION CDR ESA-19 UCB, June 14 - 18 2004

HV Supply and VMI Multiplier

A single FAST HV Supply shown with a sample FAST HV multiplier module and the commercial replacement module from VMI (HM402N10).

A total of 25 HV supplies on FAST have operated without incident for seven years.

The VMI multiplier replaces the SSL fabricated component:• Huge saving of in-house technician work• VMI part has been tested for use on STEREO• The multiplier is physically and electrically compatible with existing FAST design• THEMIS Design has a pair of dual HV Supplies

2 Dual THEMIS HV Supplies

THEMIS MISSION CDR ESA-20 UCB, June 14 - 18 2004

ESA Instrument Power Supply

Low Voltage Converter• Direct Copy of FAST Design• Regulation and Current Limiting of Primary 28 Volt Input is

Provided by IDPU Power Control Board• Reference Voltages Generated by Secondary Regulators• Power Converter Provides Isolated Grounding for ESA

THEMIS MISSION CDR ESA-21 UCB, June 14 - 18 2004

Test and Calibration

• UCB SSL has automated calibration facilities (FAST, WIND heritage) that will be used for THEMIS ESA calibrations

• Facility uses cryogenic pumped vacuum chambers with computer controlled ion and electron guns and 3-axis manipulators

• New Ion Gun Facility will be used for both ESA and SST calibrations (See SST Calibration Presentation)

• All six ESA units (5 flight/ 1 spare) use identical calibration procedures adapted from FAST

• Full environmental testing (Thermal / Vacuum, EMC, Vibration)

3 Axis Manipulator

Calibration Chamber

THEMIS MISSION CDR ESA-22 UCB, June 14 - 18 2004

ESA GSE Block Diagram

GSE workstationBenchLVPS

GPIB via USB

Ethernet GSE software: basedon Mike Hashii’sSTEREO GSE tools,FAST calibration S/W

Ethernet router

To lab network,optional externalmonitoring andcommanding

3-axis servoamplifier

Manipulator

Electronand ion guns

HVPS

Vacuum chamber

PCI motioncontroller

PWR

Digital Multimeter

EthernetESA

6U GSEInterface

Board+

Niosembeddedprocessor

Analog HSK

TM Data

TM Clock

CMD Data

CMD Clock

CMD Gate

THEMIS MISSION CDR ESA-23 UCB, June 14 - 18 2004

ESA GSE Software

Capabilities:• Scripted or interactive entry of CDI, GPIB, and manipulator

commands• Simulates ETC board to command ESA and acquire telemetry• Real-time display of counter histograms, raw hex telemetry

dumps, analog housekeeping values, manipulator status• Can act as TCP/IP server for remote monitoring or controlling via

MATLAB, IDL, or LabWindows/CVI code• Telemetry and log messages archived to disk for later examination

and processing• Device control

• GPIB programmable LV and HV power supplies, digital multimeter

• Internal PCI motion controller, external servo amp and motor drive

• TCP/IP interface to 6U VME GSE Interface Board for sending CDI commands, acquiring telemetry and analog housekeeping values

THEMIS MISSION CDR ESA-24 UCB, June 14 - 18 2004

ESA Mechanical Design

THEMIS MISSION CDR ESA-25 UCB, June 14 - 18 2004

ESA Exploded View

THEMIS MISSION CDR ESA-26 UCB, June 14 - 18 2004

Circuit Board Mounting

Interface BracketInterface Circuit BoardHigh Voltage Circuit BoardsMother Board

THEMIS MISSION CDR ESA-27 UCB, June 14 - 18 2004

ESA Exploded (Close-up)

Cover AssemblyAperture RingHemisphere AssemblyDetector BaseAnode AssemblyRadiation Shield

THEMIS MISSION CDR ESA-28 UCB, June 14 - 18 2004

ESA Anode Assembly

THEMIS MISSION CDR ESA-29 UCB, June 14 - 18 2004

Typical ESA Anode Assembly (Exploded)

AnodePlenum RingPlugRegulatorSpacer, ODSpacer, IDDowel Pin, PEEKMicro Channel Plate (MCP)Spring PlateClamp Spring, InsideClamp Spring, OutsideSpacer, ODSpacer, IDGrid, MCPClamp Ring, ODClamp Ring, ID

THEMIS MISSION CDR ESA-30 UCB, June 14 - 18 2004

Typical Hemisphere Cross-Section

Design Features:• Interior Surface of Outer Hemisphere is Serrated & Interior Surfaces of Both Hemispheres are Ebanol (Copper Black) Coated for UV Rejection• Exit Grid Isolates the Analyzer Optics from MCP Bias Voltages• Both Hemispheres Mounted to Single Structural Plate to Ensure Good Alignment

THEMIS MISSION CDR ESA-31 UCB, June 14 - 18 2004

Typical ESA HEMISPHERE Assembly

Outer HemisphereO-RingInner HemisphereDome TabDome MountGrid, HemisphereSpider Plate

THEMIS MISSION CDR ESA-32 UCB, June 14 - 18 2004

Hemisphere Cover Assembly

Hemisphere CoverCover GasketDiaphragm SpringSpring ClampGasket Clamp

THEMIS MISSION CDR ESA-33 UCB, June 14 - 18 2004

Covers Closed Cross-Section

THEMIS MISSION CDR ESA-34 UCB, June 14 - 18 2004

Covers Open Cross-Section

THEMIS MISSION CDR ESA-35 UCB, June 14 - 18 2004

Cover Release in Cocked (Closed) Position

Release PlateCompression SpringSlider, IESASlider, EESARelease SpringRollerPinRelease RodRoller ShimNut Plate, SpringNut Plate, SliderChock, SpringBushing, LinkageTube, LinkageLink, EESALink, IESABearing CapSpring MandrelBall BearingLinkage SpacerNut Plate, ActuatorBushing, Actuator LinkBearing, LinkageWasher, Actuator LinkSMA ActuatorTee BoneLink, ActuatorSwitchActuator, SwitchNut PlateSpring BlockWasher Plate

THEMIS MISSION CDR ESA-36 UCB, June 14 - 18 2004

Release Plate Mechanism Cocking

• Mechanism is cocked externally

• It is reset-able

• A “Red Tag” cocking nut may be screwed on the end of the cocking pin to prevent premature actuation of the mechanism.

• When cocked, there is an external visual indication: the tip of the cocking pin protrudes slightly from the cocking barrel.

THEMIS MISSION CDR ESA-37 UCB, June 14 - 18 2004

SMA Actuator & Mechanism Test Results

Extensive Testing

Vibration Testing• 10-27-03 Successful 4 minute GEVS test of standard NanoMuscle• 12-8-03 Successful 4 minute GEVS test of SSL redesigned SMA

Actuator (based on NanoMuscle components)• 2-23-04 Successful 4 minute GEVS test of SMA Actuator and

Release Plate Assembly (Did Not Trip Open, Did Open On Command After Vibe Test)

• Combined ESA + IDPU 6-9-04 • Final Test in Thermo-Vacuum to be done on all Flight Hardware

Cycle Testing• 2-15-04 Successful completion of three million cycle test of

previously Vibration Tested SMA Actuator.• Test Each Flight Actuator at instrument operating temps for 1000 Cycles• We will be testing Mechanism in July +/- 10 deg operational limits

THEMIS MISSION CDR ESA-38 UCB, June 14 - 18 2004

SMA Actuator Margin Analysis

• SMA Actuator rated at 125 g pull force

• Force required to pull roller off center (including spring) adjusted to be 35-40 g

• Force ratio >3

• In addition, we have an additional, redundant SMA Actuator (Pictured Right)

THEMIS MISSION CDR ESA-39 UCB, June 14 - 18 2004

Nitrogen Purge & HV Enable Plug

NITROGEN PURGE

• A Nitrogen Line is connected to the ESA Purge Fitting preflight to purge the Interior of the Analyzer.

• The Nitrogen is supplied at 5 psig and is regulated and filtered in-line at each Anode to supply 1 liter/hour.

• Purge is accessible on assembled spacecraft.

HV ENABLE PLUG

• Plug is accessible on assembled spacecraft.

HV ENABLEPLUG

THEMIS MISSION CDR ESA-40 UCB, June 14 - 18 2004

ESA S/C INTERFACE

Interface to Spacecraft

• ESA Mounts To IDPU

• ESA + IDPU Will Be Installed As a Single Unit

• ESA Extends Through Corner Panel With 0.100” Clearance all around

• “Red Tag” Purge Gas Connection and Dust Shield

• “Green Tag” Purge Gas Cover & HV Enable Plug

COCKING PIN

PURGE CONNECTOR

HV ENABLE PLUG