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