THEMIS
TIME HISTORY OF EVENTS AND MACROSCALE INTERACTIONS DURING SUBSTORMS
RESOLVING THE MYSTERY OF WHERE, WHEN AND HOW AURORAL ERUPTIONS START
THEMIS Mission Critical Design Review – ESA
June 14 – 18, 2004
University of California, Berkeley
THEMIS MISSION CDR
ESA-1
UCB, June 14 - 18 2004
ESA Plasma Instrument
Mission CDR
Dr. C. W. Carlson and THEMIS ESA Team
UC Berkeley SSL
THEMIS MISSION CDR
ESA-2
UCB, June 14 - 18 2004
Overview
ESA Plasma Instrument
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Requirements & Specifications
Heritage
Design Overview
Block Diagram
Component Descriptions
Mechanical
Test and Calibration
THEMIS MISSION CDR
ESA-3
UCB, June 14 - 18 2004
Requirements and
Specifications
Measurement
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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
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A full 4-pi distribution measurement is produced during each spin
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Sweep rate of 32/spin gives dense sample of 3-D particle distributions
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Raw measurements are compressed to selectable “reduced distributions” and moments
Implementation
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Ion and electron “top-hat” electrostatic analyzers have 180 degree field of view
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Field of view is divided into 8 electron and 16 ion elevation bins
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Plasma analyzers have hardware programmed functions: sweep rate, sweep waveform, energy
range, data collection rates. These functions are set by command.
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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-4
UCB, June 14 - 18 2004
Heritage
ESA Instrument Design is based on FAST plasma instrument
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Nearly identical measurement requirements
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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)
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Flight hardware designs and calibration facilities can be used with minor changes
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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.
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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-5
UCB, June 14 - 18 2004
Mission Requirements
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.
THEMIS MISSION CDR
ESA-6
UCB, June 14 - 18 2004
Mission Requirements
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.
THEMIS MISSION CDR
ESA-7
UCB, June 14 - 18 2004
Science Requirements
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.
THEMIS MISSION CDR
ESA-8
UCB, June 14 - 18 2004
Performance Requirements
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.
THEMIS MISSION CDR
ESA-9
UCB, June 14 - 18 2004
ESA Development Team
ESA Systems
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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
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Probe Interfaces: Ellen Taylor
Reliability and Quality Assurance (R&QA): Ron Jackson
Parts Engineering: Jorg Fischer
THEMIS MISSION CDR
ESA-10
UCB, June 14 - 18 2004
Design Overview
THEMIS Uses FAST ESA Design
(1/2 of a FAST module)
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Modular for efficient testing,
assembly and repair
Entrance sealed and nitrogen
purged
Outstanding operational
performance
MCP
Specifications:
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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
THEMIS MISSION CDR
ESA-11
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-12
UCB, June 14 - 18 2004
Block Diagram
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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-13
UCB, June 14 - 18 2004
Analyzer/Anode/Preamp
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
FAST ESA module
AMPTEK A121 preamps
Actel logic arrays
Anode and Logic board interfaces
THEMIS MISSION CDR
ESA-14
UCB, June 14 - 18 2004
MCP/Anode Board Assembly
Anode boards includes:
• MCP Mounting Hardware
“Spring finger” clamp rings
HV electrode connections
Nitrogen purge plumbing
•HV Interface
HV 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
THEMIS MISSION CDR
ESA-15
Top
Bottom
16 Anode
8 Anode
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-16
UCB, June 14 - 18 2004
HV Sweep & Digital Interface
Modified FAST
Sweep/Interface Board
Themis board is about
30 % shorter length
HV Sweep/ Interface board includes:
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Main data interface to ETC board and IDPU power board
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HV fixed and sweep supply control
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HV Sweep waveform generator (Amptek HV-601 high voltage optocouplers)
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Housekeeping multiplexer
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Plug-in interface to anodes and HV supplies
THEMIS MISSION CDR
ESA-17
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:
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Four HV supplies with interface mother board (FAST example has 6 supplies)
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Supplies are packaged as a pair of dual supplies.
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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-18
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.
2 Dual THEMIS HV Supplies
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
THEMIS MISSION CDR
ESA-19
UCB, June 14 - 18 2004
ESA Instrument Power Supply
Low Voltage Converter
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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-20
UCB, June 14 - 18 2004
Test and Calibration
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UCB SSL has automated calibration
facilities (FAST, WIND heritage) that will be
used for THEMIS ESA calibrations
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Facility uses cryogenic pumped vacuum
chambers with computer controlled ion and
electron guns and 3-axis manipulators
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New Ion Gun Facility will be used for both
ESA and SST calibrations (See SST
Calibration Presentation)
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All six ESA units (5 flight/ 1 spare) use
identical calibration procedures adapted
from FAST
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Full environmental testing
(Thermal / Vacuum, EMC, Vibration)
THEMIS MISSION CDR
ESA-21
3 Axis Manipulator
Calibration Chamber
UCB, June 14 - 18 2004
ESA GSE Block Diagram
Vacuum chamber
To lab network,
optional external
monitoring and
commanding
CMD Gate
CMD Clock
Electron
and ion guns
CMD Data
ESA
TM Clock
TM Data
Manipulator
6U GSE
Interface
Board
+
Nios
embedded
processor
Ethernet
Ethernet
router
Analog HSK
PWR
Ethernet
3-axis servo
amplifier
HVPS
GSE software: based
on Mike Hashii’s
STEREO GSE tools,
FAST calibration S/W
PCI motion
controller
Bench
LVPS
Digital
Multimeter
GSE workstation
GPIB via USB
THEMIS MISSION CDR
ESA-22
UCB, June 14 - 18 2004
ESA GSE Software
Capabilities:
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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
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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-23
UCB, June 14 - 18 2004
ESA Mechanical Design
THEMIS MISSION CDR
ESA-24
UCB, June 14 - 18 2004
ESA Exploded View
THEMIS MISSION CDR
ESA-25
UCB, June 14 - 18 2004
Circuit Board Mounting
Interface Bracket
Interface Circuit Board
High Voltage Circuit Boards
Mother Board
THEMIS MISSION CDR
ESA-26
UCB, June 14 - 18 2004
ESA Exploded (Close-up)
Cover Assembly
Aperture Ring
Hemisphere Assembly
Detector Base
Anode Assembly
Radiation Shield
THEMIS MISSION CDR
ESA-27
UCB, June 14 - 18 2004
ESA Anode Assembly
THEMIS MISSION CDR
ESA-28
UCB, June 14 - 18 2004
Typical ESA Anode Assembly (Exploded)
Anode
Plenum Ring
Plug
Regulator
Spacer, OD
Spacer, ID
Dowel Pin, PEEK
Micro Channel Plate
(MCP)
Spring Plate
Clamp Spring, Inside
Clamp Spring,
Outside
Spacer, OD
Spacer, ID
Grid, MCP
Clamp Ring, OD
Clamp Ring, ID
THEMIS MISSION CDR
ESA-29
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-30
UCB, June 14 - 18 2004
Typical ESA HEMISPHERE Assembly
Outer Hemisphere
O-Ring
Inner Hemisphere
Dome Tab
Dome Mount
Grid, Hemisphere
Spider Plate
THEMIS MISSION CDR
ESA-31
UCB, June 14 - 18 2004
Hemisphere Cover Assembly
Hemisphere Cover
Cover Gasket
Diaphragm Spring
Spring Clamp
Gasket Clamp
THEMIS MISSION CDR
ESA-32
UCB, June 14 - 18 2004
Covers Closed Cross-Section
THEMIS MISSION CDR
ESA-33
UCB, June 14 - 18 2004
Covers Open Cross-Section
THEMIS MISSION CDR
ESA-34
UCB, June 14 - 18 2004
Cover Release in Cocked (Closed) Position
Release Plate
Compression Spring
Slider, IESA
Slider, EESA
Release Spring
Roller
Pin
Release Rod
Roller Shim
Nut Plate, Spring
Nut Plate, Slider
Chock, Spring
Bushing, Linkage
Tube, Linkage
Link, EESA
Link, IESA
Bearing Cap
Spring Mandrel
Ball Bearing
Linkage Spacer
Nut Plate, Actuator
Bushing, Actuator Link
Bearing, Linkage
Washer, Actuator Link
SMA Actuator
Tee Bone
Link, Actuator
Switch
Actuator, Switch
Nut Plate
Spring Block
Washer Plate
THEMIS MISSION CDR
ESA-35
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-36
UCB, June 14 - 18 2004
SMA Actuator & Mechanism
Test Results
Extensive Testing
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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-37
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-38
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
HV ENABLE PLUG
• Plug is accessible on assembled spacecraft.
THEMIS MISSION CDR
ESA-39
UCB, June 14 - 18 2004
ESA S/C INTERFACE
Interface to Spacecraft
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ESA Mounts To IDPU
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ESA + IDPU Will Be
Installed As a Single Unit
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ESA Extends Through
Corner Panel With 0.100”
Clearance all around
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“Red Tag” Purge Gas
Connection and Dust
Shield
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“Green Tag” Purge Gas
Cover & HV Enable Plug
COCKING PIN
PURGE CONNECTOR
HV ENABLE PLUG
THEMIS MISSION CDR
ESA-40
UCB, June 14 - 18 2004