Transcript SDO Systems

SDO Electrical Subsystem
Mission PDR
Paul Kim (Lead)
Gary Won (Electrical Systems Engineer)
Mike Blasi (Harness Engineer)
Vernon McCarter (Fabrication Lead)
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 1
Agenda
•
Introduction
•
Requirement Summary
•
Electrical System Interface Diagram
•
Power Distribution
•
Signal Interfaces
•
Charging and Discharging
•
EMI/EMC
•
Grounding
•
System Grounding Diagram
•
Harness Design
•
Harness Development Flow
•
Verification
•
RFA Status
•
Risk Identification and Mitigation
•
Document Status
•
Schedule
•
Summary
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 2
Introduction
•
Electrical System
The electrical system includes electronics components, interconnect harnessing, the structural
chassis grounding system, grounding of external coatings and thermal blankets, and elements that
provide shielding.
•
•
Electrical Systems Drivers
–
GEO Charging Environment
–
Common Mode Noise Control
–
High Data Rate Support
–
GEO Radiation Environment
–
Electrical Interface Robustness
–
RF Radiation Environment
Strategy for Implementing the Design Drivers
–
Early Definition of the Key Electrical System Design Concept (i.e., Faraday Cage)
–
Comprehensive Requirement Development (Electrical System Specification)
–
Communicating the Electrical System Requirements That Drive the Other Subsystems and
Instrument Design
–
Integrated Electrical Requirement Allocation, Implementation, and Verification
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 3
Electrical Systems Requirement Summary
•
Power Interface Requirements
•
Grounding Requirements
•
EMI/EMC Requirements
•
Radiation Environment
•
Magnetic Dipole Requirement
•
Data and Signal Interface Requirement
•
Multipaction and Corona
•
Differential Charging
•
Surface Charging Mitigation and Protection
•
Internal Charging Mitigation
•
Shield Termination at Electrical Interface
•
Arm/Safe Plug Requirements
•
Harness Requirements
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 4
SDO Electrical Systems Interface Diagram
5 LB
ENG
REVISION
5 LB
ENG
ZONE
5 LB
ENG
REACTION
WHEEL
5 LB
ENG
IRU 1
SPACECRAFT
MODULE
IRU 2
DATE
DESCRIPTION
APPROVAL
IRU 3
ACE A
ACE B
ACE A & B
INST UMBICAL
ST 1
ACE A & B
HEB
ELECTRONICS
PSE OM3
-HGAS
-HGAS
+HGAS
+HGAS
UMBICAL
UMBICAL
ACE A & B
INSTRUMENT THERMISTORS
INSTRUMENT HEATERS, (QTY 4).
INSTRUMENT HEATERS, (QTY 4).
1553
PROPULISION
MODULE
ST 2
GCE B
GCE A
SPACECRAFT MODULE THERMISTORS
ACE A & B
INSTRUMENT
MODULE
UMBICAL
HOUSE KEEPING
UMBICAL
PSE OM6
ACE A & B
1553
+Z GIMBAL
-Z GIMBAL
PSE OM2
1553
+Z GIMBAL
-Z GIMBAL
PSE OM3
PSE OM4
1553
100 LB
ENG
PSE
BATTERY MODULE
REACTION
WHEEL
1553
C&DH A C&DH B
TO BATTERY
TO ACE A
OUTPUT MODULE #1
REACTION
WHEEL
TO C&DH B
TO ACE B
PSE OM#1
PSE OM#4
TO GCE B
PSE OM#5
OUTPUT MODULE #2
PSE OM#2
BATTERY
TO C&DH A
HMI
PSE OM3
TO INST
OUTPUT MODULE #3
TO GCE A
OPTICS
ACE A
ACE B
PYRO VALVE FUSISTOR PLUG A
PYRO VALVE FUSISTOR PLUG B
ST1 & ST2
ST1 & ST2
5 LB ENGINE PWR A
5 LB ENGINE PWR B
PSE OM#4
PSE OM#2
TEST CONN. PROP A
ST1 & ST2
PYRO VALVE FUSISTOR PLUG A
PYRO VALVE FUSISTOR PLUG B
ST1 & ST2
1553
TEST CONN. PROP B
OPTICS
5 LB ENGINE SIG A
PSE OM#3
INSTRUMENT PWR A & B
5 LB ENGINE SIG B
UMBICAL
PROP TEST CONN. A
RW 1-4
AIA
INST FEED THRU
PROP TEST CONN. B
1553
PSE OM3
PSE OM3
ACE B
S/A +Y & -Y
S/A +Y & -Y
KA
AIA
ELECTRONICS
PROP TEST CONN. B
PROP TEST CONN. A
UMBICAL
SPN MODULE
5 LB ENGINE PWR A
5 LB ENGINE PWR B
ACE A
TO S/A +Y & -Y
IRUs
IRUs
C&DH A & B
RW 1-4
SOLAR ARRAY MODULE
A TO S/A +Y & -Y
TO S/A +Y & -Y
B TO S/A +Y & -Y
TO GCE B
TO PYRO'S
S/A +Y & -Y
S/A +Y & -Y
TO C&DH A
TO PYRO'S
TEST CONN. PROP B
OUTPUT MODULE #5
OUTPUT MODULE #6
DEPLOYMENT MODULE
1553
TO ACE A
TEST CONN. PROP A
PSE OM#1
TO C&DH B
TO GCE A
IRUs
IRUs
C&DH A & B
RW 1-4
RW 1-4
5 LB ENGINE SIG A
5 LB ENGINE SIG B
ACE A
ACE B
OUTPUT MODULE #4
PSE OM#5
TO ACE B
INSTRUMENT SIG A
INSTRUMENT SIG B
PSE OM3
INST UMBICAL
EVE
REACTION
WHEEL
OPTICS &
ELECTRONICS
S-BAND
XPNDR 1
KA
BAND
INST UMBICAL
KA
BAND
PSE OM3
ACE A
S-BAND
XPNDR 2
ACE B
THRUST VALVE TURN-AROUND PLUG B
THRUST VALVE TURN-AROUND PLUG A
ISOLATION TURN-AROUND PLUG B
XXXXXXXX
ISOLATION TURN-AROUND PLUG A
PROPULISION PWR B
PROPULISION PWR A
PROPULISION SIG B
PROPULISION SIG A
5 LB ENGINE SIG B
5 LB ENGINE SIG A
5 LB ENGINE PWR B
OUTSIDE
SPACECRAFT
MODULE
GCE A& B
Goddard Space Flight Center
TEST CONNECTOR DISCONNECT
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION, GREENBELT, MARYLAND
NAME
INIT
DATE
DESIGNED & DRAWN BY
V. McCarter
FLIGHT ELECTRAIL SYSTEMS APPROVAL
P. Kim
REVIEWED BY
+Z
G. Won
-Z
POWER PDL APPROVAL
THIS DRAWING WAS PRODUCED USING
SOFTWARE:
FILE NAME:
SDO Preliminary Design Review (PDR) – March 9-12, 2004
GD
OMNI -X
-Z GIMBAL
-HGAS SIG
- HGAS PWR
+Z GIMBAL
OMNI +X
GCE A& B
PSE DEPLOYMENT MOD
GCE A& B
PSE DEPLOYMENT MOD
+ HGAS PWR
GCE A& B
ACE A & B
ACE A & B
PSE
DEPLOY FUSISTOR PLUG A
DEPLOY FUSISTOR PLUG B
ISOLATION TURN-AROUND PLUG A
ISOLATION TURN-AROUND PLUG B
PSE POWER
PROPULISION PWR A
PROPULISION PWR B
THRUST VALVE TURN-AROUND PLUG A
THRUST VALVE TURN-AROUND PLUG B
1553 BUS TURN-AROUND A
1553 BUS TURN-AROUND B
+ HGAS SIG
ACE A & B
PROPULISION SIG A
PROPULISION SIG B
PSE SIGNAL
UMBILICAL #1
C&DH & GCE
UMBILICAL #2
PYRO ARM PLUG A
PSE DEPLOYMENT MOD
PYRO ARM PLUG B
PYRO VALVE FUSISTOR PLUG A
PYRO VALVE FUSISTOR PLUG B
ACS
TO PYRO'S
(QTY 26)
5 LB ENGINE PWR A
5 LB ENGINE PWR B
5 LB ENGINE SIG A
5 LB ENGINE SIG B
BAT TEST CONNECTOR
ACE A & B
THERMISTORS
SOLAR SOLAR
ARRAY ARRAY
+Y
-Y
ACE A & B
ACE A & B
THERMISTORS
PSE S/A MOD A
PSE S/A MOD B
PSE S/A MOD A
5 LB
ENG
ACE A & B
5 LB
ENG
PSE S/A MOD B
5 LB
ENG
ACE A & B
5 LB ENGINE PWR A
5 LB
ENG
AUTOSKETCH VERSION: 7.1
XXXXXXXX
C&DH PDL APPROVAL
ACE PDL APPROVAL
NASA/Q.A. APPROVAL
03/01/03
DRAWING INTERPRETED PER GSFC-X673-64-1
Solar Dynamics Observatory
SPACECRAFT BUS
TOP LEVEL
HARNESS DRAWING
GD
CODE
XXXXXXXX
SCALE
WT
SH 1 OF 1
Electrical Page 5
Power Distribution
•
•
•
•
•
•
•
•
•
•
•
Cross-strapped PSE Switched Output to high power
Subsystems (PCC & LPSC) and Instruments.
Cross-strapped LPSC Switched Output to low power
components and heaters.
Cross-strapped Fused Unswitched Output to power
communication-critical components.
Power inputs for the survival, propulsion, and instrument
decontamination heaters are block redundant.
There is a dedicated power input for the pyro and other
deployable actuators.
All returns, except instrument decontamination heaters, are
unswitched.
Operational power distribution configurations will be the
primary (all A side), the redundant (all B side), and the
selectively cross-strapped (A and B mixed).
Ground test will verify all operational configurations and all
copper paths in the power distribution system.
No damages to the Observatory by mis-configuring power
distribution system.
SSPC Load current is derated to 90% of rated current
Voltage Drop Verified:
–
–
<1 volt drop estimated between EPS OM and LPSC loads
<19W power dissipation estimated (w/o S/A Harness)
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Cross-Strapped Power Interface with OM and LPSC
PSE OM #1 (A)
10 A
C&DH LPSC (A)
Electronics A
To DC/DC
Convertor
2A
2A
PSE OM #4 (B)
10 A
C&DH LPSC (B)
Electronics B
To DC/DC
Convertor
2A
2A
Cross-Strapped Power Interface with OM
PSE OM #1 (A)
Electronics A
10 A
To DC/DC
Convertor
PSE OM #4 (B)
10 A
PSE OM #2 (A)
Electronics B
10 A
To DC/DC
Convertor
PSE OM #5 (B)
10 A
Electrical Page 6
Unswitched Bus
SDO Preliminary Design Review (PDR) – March 9-12, 2004
FET #6
15 A
FET #5
15 A
FET #4
5A
FET #3
5A
FET #2
5A
FET #1
5A
PSE DM (TBD)
Unswit #2
Unswit #1
SSPC #8
5A
SSPC #7
5A
SSPC #6
10 A
SSPC #5
10 A
SSPC #4
10 A
SSPC #3
10 A
SSPC #2
10 A
SSPC #1
15 A
PSE OM #3
Unswit #2
Unswit #1
SSPC #8
5A
SSPC #7
5A
SSPC #6
10 A
SSPC #5
10 A
SSPC #4
10 A
SSPC #3
10 A
SSPC #2
10 A
SSPC #1
15 A
PSE OM #2
Unswit #2
Unswit #1
SSPC #8
5A
SSPC #7
5A
SSPC #6
10 A
SSPC #5
10 A
SSPC #4
10 A
SSPC #3
10 A
SSPC #2
10 A
SSPC #1
15 A
PSE Output
Module (OM) #1
1A
1A
1A
1A
1A
Ka Transmitter-A
[ Spare ]
S-band Receiver-A
2A
2A
2A
2A
1A
1A
GCE-B LPSC & PCC (to Page 2)
Pyro Valve NO-A Power (to EVD A)
Pyro Valve NC-A Power (to EVD A)
HGAS -Z Deploy-A Power
HGAS +Z Deploy-A Power
S/A -Y Deploy-A Power
S/A +Y Deploy-A Power
[ Spare ]
[ Spare ]
Prop Lower Support Heater #1A
EVE
HMI-B
HMI-A
Instrument Decontam Heater Bus-A
AIA-B
AIA-A
EVD-B Drive Power
S-band Comm Card-B (to Page 2)
S-band Receiver-B
ACE-B PCC ( to page 2)
Ka Transmitter-B
[ Spare ]
Instrument Survival Heater -A
GCE-A LPSC & PCC
1A
1A
1A
1A
1A
1A
1A
2A
1A
2A
2A
2A
GCE-A PCC
GCE-A
C&DH-A PCC
C&DH-A
ACE-A Power
Convertor Card (PCC)
ACE-A
SW #15: Optical Bench Heater #7A
SW #16: Optical Bench Heater #8A
SW #14: Optical Bench Heater #6A
SW #13: Optical Bench Heater #5A
SW #12: Optical Bench Heater #4A
SW #10: Optical Bench Heater #2A
SW #11: Optical Bench Heater #3A
SW #8: [Spare]
SW #9: Optical Bench Heater #1A
SW #6: [Spare]
SW #7: [Spare]
SW #5: [Spare]
SW #3: - HGA Gimbals (Azimuth)
SW #4: - HGA Gimbals (Elevation)
SW #1: + HGA Gimbals (Azimuth)
SW #2: + HGA Gimbals (Elevation)
GCE-A LPSC & PCC from
PSE-B (from Page2)
SW #16: -Z HGAS Damper HTR-A
SW #14: -Y S/A Damper HTR-A
SW #15: +Z HGAS Damper HTR-A
SW #13: +Y S/A Damper HTR-A
SW #12: [Spare]
SW #11:Prop External HTR Power #2A
SW #9: Prop Line HTR-A
SW #10:Prop External HTR Power #1A
SW #7: Prop Lower Support HTR #2A
SW #8: Prop Upper Support HTR-A
SW #6: S-Band Transmitter-B
SW #5: S-Band Transmitter-A
SW #3: SBC & Bulk Memory-A
SW #4: SBC & Bulk Memory-B
SW #2: Ka Comm Card-B
SW #1: Ka Comm Card-A
C&DH-A PCC from PSE-B
(from Page2)
SW #15: [Spare]
SW #16: [Spare]
SW #14: [Spare]
SW #12: RW Command Drive Power
SW #13: [Spare]
SW #10: Pressure X-ducer Power #2
SW #11: IRU Command Drive Power
SW #8: [Spare]
SW #9: Pressure X-ducer Power #1
SW #6: Iso Valve Open Drive Power
SW #7: Iso Valve Close Drive Power
SW #5: Star Tracker #2
SW #3: IRU #3
SW #4: Star Tracker #1
SW #1: IRU #1
SW #2: IRU #2
ACE-A PCC from PSE-B
(from Page2)
Power Distribution Diagram , Page 1
Note : Default state of all SSPC’s are TBD.
1A
1A
1A
1A
1A
1A
1A
2A
1A
2A
2A
2A
2A
2A
Reaction Wheel #3
Reaction Wheel #4
2A
2A
EVD-A Drive Power
C&DH-A PCC
2A
1A
2A
2A
2A
2A
2A
2A
2A
S/C Bus Survival Heater-A
ACE-A PCC & LPSC
Reaction Wheel #2
Reaction Wheel #1
C&DH-A Low Power Switching Card
(LPSC)
SDO Power Distribution Diagram (‘A’ Side)
Power Distribution (A Side)
Note: B-side assignment is shown in the back-up charts
Electrical Page 7
Signal Interfaces (1/2)
•
•
•
•
1553B Bus
–
1553 Bus user interfaces the bus with stub coupler (1:1.41 stub to bus ratio)
–
The 1553B Bus cable will be built and tested separately from the S/C harness.
High Speed Bus
–
1355 bus interface between instrument data interface to C&DH Ka-com card with the SpaceWire
cables manufactured based on ECSS-E-50-12 standard.
–
LVDS interface between Ka-com downlink to Ka-modulator with 26 AWG 100 ohms shielded and
jacketed differential cables with triax connectors.
Thermal Interface (Heaters and Sensors)
–
S-311-P18-05A thermistor and Goodrich model 118MF PRT are standard temperature sensors.
–
22 AWG for survival heater and 24 AWG, or high-strength 26 AWG, for thermal sensors.
Deployment Interface
–
Autonomous S/A deployment with a ground command back-up
–
Ground Initiated command HGA deployment
–
Positive telemetry indication of deployment and latch status
–
Three independent inhibits (i.e., S/A actuator enable, individual arm, and fire) to prevent premature
or inadvertent deployment
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 8
Signal Interfaces (2/2)
•
•
Pyro Actuated Valve Actuation Interface
–
Ground-initiated command to actuate nine pyro valves to isolate propulsion fuel, oxidizer, and
pressurization system.
–
Three independent inhibits (i.e., NO or NC valve enable, individual arm, and fire) for premature or
inadvertent actuation (two fault tolerant).
Test Connector Interface
–
Spacecraft skin test connectors will be available to support system I&T and environmental tests.
• Propulsion: Isolation valve turn-around plug (A&B), thruster valve turn-around plug (A&B), and
prop test connector.
• Power: EPS/battery power and EPS/battery signal connector.
• ACS: Dedicated test connector.
• C&DH: 1553 bus terminator plug (A & B), shared test connector with GCE.
• RF: -Z Omni test connector.
–
•
All the signals for the test connector must be protected or isolated to prohibit fault propagation from
the test facility or EGSE.
Launch Vehicle Interface (Umbilical Connection)
–
Two 61 pin connectors were selected for L/V umbilical interface connectors
–
Each PSE and ACE will receive three dedicated signals for the launch vehicle separation.
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 9
Charging and Discharging Requirements
•
External Component Surface Charging Mitigation
–
–
–
–
•
Internal Charging Mitigation
–
–
–
•
Sufficient Sun side conductive area bleeds bulk charges.
Spacecraft external surfaces conductivity must be maintained to <109 ohm/square.
No more than 10 non-conductive surfaces (>109 ohm/square) of 6 cm2 in 1 m2 surface area. It
should be noted that each 6 cm2 dielectric can generate up to 10 A common mode current
and 200-1,000 V E-field for 100 usec.
Unavoidable dielectrics accepted by waiver assume a detailed analysis or test indicates no
ESD discharge impacts to system.
Electronics boxes will have greater than 110 mil Aluminum equivalent protection either from
the spacecraft structure and its own housing.
60 mil Aluminum equivalent protection for external harness dielectric will be provided to
preclude the internal charging effects (60 mil Al or 12 mil Lead).
Another potential solution for the harness internal charging is to filter nearby circuitry to
withstand a 5,000 Volt 20 pf 10 ohm discharge, or detailed analysis of discharge could result
in smaller or larger discharge source than above.
Protection from ESD-Induced Noise
–
–
Build the Faraday cage to keep the external noise out of the “Quiet” region of the spacecraft.
40 dB RF attenuation must be provided between the “Quiet” portion (inside of the bus module
or instrument OP) of the spacecraft, and ESD-induced noise from discharges of unavoidable
dielectrics and waivered materials.
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 10
Charging and Discharging Req Traceability
SDO ESD Requirements
ESD Mitigation: ESD Robust Design, Faraday Cage (40 dB RFI
Shielding Effectiveness)
Traceability of SDO Requirements
GOES (GOES N-Q Environment Spec)
NASA Requirements (NASA Tech #2361 and Prevention and "ESD" Robust Design, Faraday Cage(40
NASA-HDBK-4002)
dB SE)
Surface Conductivity: Less than 10 9 ohm/A with exceptions (less than NASA Tech #2361
ten 1 inch Sq non-conductive areas per 1mSq)
Less than 10 9 ohm/A (except S/A, magnetometer boom,
Antenna and less than ten 1 inch sq non-conductive areas
per 1mSq)
Bonding:2.5 milliohm bonding and 10 milliohm between all components NASA Tech #2361, GEVS, and Heritage
requirements
(exceptions for HGA ECRA sliprings)
Low Impedance
Component Grounding: Co-therm with copper sheet frame for
internally mounted components (on Al facesheet), or 4~6 mil thick
Copper Grounding Strap (s) with 5:1 ratio for components on nonconductive surface
Harness Shielding: 1 mil, 50 % overwrap, Al tape with EMI connector
backshells for 40 dB RFI attenuation from surface charges
MAPS Heritage
Baseplate metal to metal contact and two additional 10 mil
thick Gold Plated Al strap 3:1 ratio. Low impedance
connection (as approved by survivability) for components
on non-conductive surface
NASA Tech #2361 and NASA-HDBK-4002
60 mil Al equivalent or 20 mil Cu over braid for those
components susceptible to harness insulation discharge
and many more shielding effectiveness requirements
Internal Charging: 110 mil Al equivalent shielding for internal dielectrics NASA-HDBK-4002
and 60 mil Al equivalent (12 mil Pb) shielding for the Teflon harness
insulation
ESD Protection: Low pass ESD Filter at the entrance of Bus Faraday
Cage
NASA Tech #2361
Non-compliance Disposition: ESD Assessment analysis to show that NASA Tech #2361 and NASA-HDBK-4002
any non-compliant items would not damage the "victim' hardware and
disrupt with the essential Spacecraft functions
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Incident Electron Flux Analysis, PWB material selection,
and piece part spot shielding to mitigate the internal
charging effects
404, 680, and 1380 pf Low Pass ESD Filter at the
Spacecraft FC entrance
Analysis and test to show that any non-compliant items
would not damage the "victim' hardware
Electrical Page 11
ESD Mitigation for Harness
•
Faraday Cage Penetration will only be accommodated
through the circular feed through (LJT) connector or harness
conduit.
•
The circular connector will be used for the Power and other
low frequency signals. These signals will be filtered at the
inline filter module.
•
Intra-instrument or other non-filtered signal will be routed
through the harness conduit. To maintain the effective
isolation of the FC, the outer shield will be terminated with
360º continuous bonding to the conduit.
•
100% coverage of harness, connector, and backshell with Al
tape (RFI shielding). ESD shielding will be applied on the top
of the Al tape.
•
Individual shield will be terminated at the connector backshell
with a short pig tale (SpaceWire, LVDS and some RF cables
are the only exceptions to this rule).
•
Outer bundle shield and inner shield will not be tied to any
connector pins (SpaceWire and LVDS cables are the only
exceptions to this rule).
•
Copper tape will be used to cover any gaps between the
connector backshell and the connector mounting panel.
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 12
EMI/EMC Test Requirements
•
EMI/EMC Test Levels
Box-level EMI/EMC test (CE, CS, RE, and
RS).
Test Description
Test Level
Issues/Comments
Conducted Emissions
–
–
–
•
•
•
•
Instrument electronics
EPS, C&DH, GCE, ACE, R/W and
AST
S-band transponder and Ka
transmitter
CE01/03, NB
120 to 20 dbuA
CE06
RF Components Only
Conducted Susceptibility
CS01
2.8VRMS/40 Watts
CS02
1.0 VRMS/1 Watt
CS06
28V+/- 28V, 10usec Pulse
CS03, CS04, CS05
RF Receivers Only
Radiated Emissions
Observatory-level test (RE, RS, and RF
self-compatibility test).
RE02, NE
100 Volts/m test requirements at Ka
transmitter frequency were derived from
the recent E-field prediction at the IM
locations when the antenna was
inadvertently pointing directly to the
instrument. Expected E-field during
nominal operation is less than 3 V/m.
RS03,2 -12GHz
5 Volts/m
RS03, 12 - 28 GHz
10 Volts/m
Externally mounted component must
survive the E-field from Ka antenna beam.
20 to 65 dBuV/m
+10 dB for Observatory Limit
Radiated Susceptibility
RS03,14 KHz-2GHz
2 Volts/m
RS03, 2.22 GHz
7 Volts/m
RS03, 25.5 - 27.5 GHz
100 Volts/m
RS03, Launch Site/Vehicle Freq
Ka Antenna Direct Radiation
TBR
Launch Site/Vehicle Originated Test Levels
Test Level
Requirement Source
2.2415 GHz
Frequency Range
40 V/m
(Delta IV) S-Band **
5.762-5.768 GHz
40 V/m
(Delta IV) C-Band **
2.2 – 2.5 GHz
45 V/m
(Atlas V) S-Band **
5.6 – 5.8 GHz
45 V/m
(Atlas V) C-Band **
<100 mVp-p Common Mode Noise for
SDO Components and Instruments.
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 13
Grounding
•
Spacecraft Grounding
–
–
•
Bus module structure panels, propulsion deck, and other primary structure members are
electrically bonded (< 2.5 milliohms) to form the spacecraft common ground.
The Spacecraft common ground is extended to the composite instrument module structure
by installing the 4 ~6 mil thick copper sheet with a 5:1(length to width) ratio from the bus
module structure to the instrument mounting plate.
Single-Point Power Grounding
–
–
–
•
Unregulated bus (primary) DC current returns to a single point at PSE, and the PSE single
return is then tied to the –Y bus module panel (Al face-sheet of honeycomb panel) via
current shunt.
Solar array and battery power returns are tied to the PSE single point via current shunts.
Primary power returns from subsystem users are returned their respective power sources.
Distributed Signal Grounding
–
•
Secondary power returns are tied to chassis ground in each component load at multiple
points (with low inductance paths).
Electronics Component Bonding
–
–
–
Electrical bonding is achieved through metal-to-metal contact between component
baseplate/mounting feet to Aluminum panel face-sheet.
Grounding strap/bracket will be used on the electronics mounted on the composite or that
do not meet 2.5 milliohm bonding requirements.
HGA boom (Aluminum) and solar array panels (Al honeycomb and composite face-sheet)
are connected to the bus module structure with grounding straps or wires.
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 14
Systems Grounding Diagram
REVISION
5 LB
ENG
5 LB
ENG
1
ZONE
1
5 LB
ENG
5 LB
ENG
PROPULISION
MODULE
(ALUMINUM)
1
SPACECRAFT
BUS MODULE
(ALUMINUM HONEYCOMB)
1
6
4
REACTION
WHEEL #4
6
4
REACTION
WHEEL #2
6
4
REACTION
WHEEL #2
REACTION
WHEEL #1
DATE
DESCRIPTION
APPROVAL
INSTRUMENT
MODULE
(COMPOSITE)
6
4
1
4
D
AIA OPTICS
CAMERA #2 ELECTRONICS
CAMERA #1 ELECTRONICS
A
FUEL TANK
(TITANIUM)
CAMERA #3 ELECTRONICS
-Z
CAMERA #4 ELECTRONICS
1
6
C&DH B
C&DH A
A
6
6
4
PSE
+5V, +3.3V & 2.5V
6
4
BATTERY
D
A
D
A
D
A
D
1
4
AIA
ELECTRONICS
PRIMARY
Ka-COMM
D
+15V
X8
A
STAR TRACKER 1
D
1
4
REDUNDANT
A
SBC
+5V, +3.3V & 2.5V
D
OXIDIZER
TANK
(TITANIUM)
1
PREASSURE
TANK
(COMPOSITE
OVER
TITANIUM)
1
PREASSURE
TANK
(COMPOSITE
OVER
TITANIUM)
A
D
D
STAR TRACKER 2
GROUND PLANE
IN MOTHER BOARD
1
+5V, +3.3V & 2.5V
D
S-COMM
D
HMI
ELECTRONICS
+15V
A
1
4
4
1
CAMERA #2 ELECTRONICS
CAMERA #1 ELECTRONICS
A
6
4
ACE A
1
4
HMI OPTICS
PRIMARY
1
100 LB
ENG
+Z
1
4
D
REDUNDANT
A
6
4
ACE B
A
+5V, +3.3V & 2.5V
D
A
D
D
+/-15V
+5V
D
8x TRANSDUCERS
PRESSURE
TRANSDUCER
+/-15V
+15V
+5V
+/-15V
EVE ELECTRONICS
1
+5V
PRIMARY
SHIELD
EVE OPTICS
SECONDARY
SHIELD
ELEC. MOTHERBOARD
+15V
ESP ELECTROMETERS
+28V
A
+5V, +/-15V, +15V
A
A
KA BAND
RTN
6
4
KA BAND
D
D
ESP BIAS SUPPLY
6
4
IRU 3#
D
6
IRU #2
6
IRU #1
MEGS CCD PS & POST REGULATOR BOARD
6
INSTRUMENT
SUPPLIED
A
1
4
+/-5V, +/-15V, 24V
+28V
CCD ELECTRONICS
D
6
4
GCE B
GCE A
A
RTN
6
4
+5V, +3.3V & 2.5V
S BAND TRANMITTER
A
A
D
D
1
4
S BAND TRANSMITTER
+15V
19x BUS
STUBS
D
1553
BUS
STUB
D
1
A
A
20 AWG
WIRE
S BAND RECEIVER
XXXXXXXX
1
4
+5V & +2.5
INSTRUMENT GND BUS BAR FOR
BLANKETS AND OTHER SHIELDS
1
1
5 LB
ENG
5 LB
ENG
1
4
1
4
1
4
1
5 LB
ENG
4
1
COPPER STRAP
GD
1
5 LB
ENG
D
COPPER STRAP
OUTSIDE
SPACECRAFT
MODULE
NOTES:
1. Unless otherwise noted it is assumed that all
boxes and components are Dry (Hard) Mounted.
2. The Hex Hub has 2.5 mil Al foil bonded to the
outside surface.
3. A dotted line (
) represents an isolated
box, component or surface. (See additional notes.)
22 OR 20 AWG WIRE
22 OR 20 AWG WIRE
LEGEND
22 OR 20 AWG WIRE
22 OR 20 AWG WIRE
1
CSS
+Z
-Z
SOLAR
ARRAY
+Y
SOLAR
ARRAY
-Y
SDO Preliminary Design Review (PDR) – March 9-12, 2004
1
CSS
1 Dry Mount (Hard Mounted)
8 Copper Ribbon (0.001 x 1 Inch)
15 Coaxial Shield
2 Conductive Copper Tape
3 Eccobond 56C Conductive Epoxy
9 Ground Wires (Within Harness)
16 Al Foot With Ti Flexures
10 Conductive Paint NS43G
Goddard Space Flight Center
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION, GREENBELT, MARYLAND
NAME
Conductive Material/Surface
V. McCarter
Non-Conductive Material/Surface
FLIGHT ELECTRAIL SYSTEMS APPROVAL
17 Titanium (Ti) Flexures
Hx
Harness # x.
4 Ground Strap, Copper
11 G10 Spacers
18 Nu Sil
Sx
Structure # x.
MLI & RFD Blanket
5 Thermal Plate
12 Clickbond Studs
Tx
Thermal # x.
__________
MLI Blanket
P. Kim
REVIEWED BY
6 Chotherm With Cu Picture Frame
13 White A276 Dissipative Paint
19 Ultem 1000
20 Epon 828/TiO2
7 19 Ultem Spacer
14 Attached To Through-Bolt
21 Heat Strap 0.010" Thick Cu w/ Indium End Fittings
SOFTWARE:
22 Aluminum Honneycomb
FILE NAME:
INIT
DATE
DESIGNED & DRAWN BY
THIS DRAWING WAS PRODUCED USING
AUTOSKETCH VERSION: 7.1
XXXXXXXX
G. Won
POWER PDL APPROVAL
C&DH PDL APPROVAL
ACE PDL APPROVAL
NASA/Q.A. APPROVAL
03/01/04
DRAWING INTERPRETED PER GSFC-X673-64-1
Solar Dynamics Observatory
SDO SPACECRAFT
SYSTEM GROUNDING
DIAGRAM
GD
CODE
XXXXXXXX
SCALE
WT
SH 1 OF 1
Electrical Page 15
Harness Design
•
•
S/C Harness Budget
–
S/C Harness Mass Budget: 137 Kg estimate vs. 154 Kg allocation
–
S/C Harness Power Dissipation: <19W estimate (w/o S/A) vs. 22.5 W allocation
Harness Deliverable
–
Flight Harness
–
FlatSat Harness: (Single Sided)
–
C&DH S/W Lab cables
–
ACE S/W Lab cables
–
EGSE cables
–
Thermal Vacuum Test cables
–
Break-Out-Boxes
–
Arm and Safe Plugs
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 16
Harness Design
•
Group each harness in accordance with the power and signal interface need of each
subsystem, component, or instrument.
•
Separate power harness and connectors from signal harness and connectors.
•
Twist all power and return wires in A- and B-side harness to a single bundle.
•
When routing harness external to the Observatory, use either conduit or filtered circular
connector.
•
The QWKNUT harness shall be a twisted and shielded cable without any interruption in
the outer shield.
•
All electrical harness will be shielded against ESD environment and will have EMI
backshell over connector.
•
At every 24 inches, the outer bundle shield of harness will be grounded to the
spacecraft.
•
Wires and connector are to be derated per EEE-INST-002
•
Harness Mockup will be used for routing and length check during assembly and test
phase.
•
The configuration of the mock-up must be controlled under CM to reflect any future
changes.
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 17
Harness Development Flow
Develop Subsystem
ICDs
Specify Harness
Req (Elec. Sys.
Spec.)
Harness Drawings
(Subsystem ICD)
2nd Peer Review
(CDR)
Preliminary Harness
Layout and Routing
First Peer Review
(PDR)
Finalized Harness
Layout and Routing
Harness Fabrication
on Bus Mock-up
Harness Mock Up
Delivered
Part Procurement
(Start with Long
Lead Items)
Pin Retention Test
Milli-Ohms Test &
Hi-Pot Test
Bake Out
Milli-Ohms Test &
Hi-Pot Test
Pre-Delivery
Review & Close out
of all Open Issues
Harness Delivery
Install Harness
Integration and Test
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 18
Electrical Systems Verification
•
Electrical Interface Verification (Interface Analysis)
–
–
–
Electrical interface verification will be performed on the inter-component interfaces to assure
the circuit compatibility and electrical systems specification compliance and will be measured
during box level integration.
I/O device compatibility, noise immunity (source – victim analysis), timing, device loading,
EMI/EMC filtering, grounding, fault isolation, and other interface requirements will be verified
against the electrical system specification.
Results of verification will be documented in the electrical systems analysis report.
•
Charging and Discharging Verification
– Spacecraft surface charge analysis will be required to determine surface
potentials and voltage gradients, spark discharge parameters (amplitude,
duration, and frequency content), and EMI coupling.
– Each dielectric material size > 6 cm2 will be assessed for its breakdown voltage,
its ability to store energy, and the effects it can have on neighboring electronics
(disruption or damage) and surfaces (erosion or contamination).
– Electrical systems will measure resistance of all the spacecraft surface material
and maintain the project database.
•
Interface FMEA
–
–
Electrical interconnection information will be supplied to reliability engineers for interface
FMEA.
Connector pin assignments and harness design will be analyzed so that a single connection
failure will not result in loss of mission or catastrophic damages to the spacecraft.
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 19
Action Item and RFA Status
12 System Action Items: 1 open and 11 Closed
16 RFAs:
2 Major RFAs: Closed. A demonstration is planned for Summer.
#624: Demonstrate Spacewire & LVDS cable bit error rate req in the presences of
100mVp-p Common Mode Noise.
#633: Same as #624
7 Medium RFAs: 6 closed and 1 pending closure
7 Minor RFAs: 5 closed and 2 pending closure
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 20
Risk Identification and Mitigation (Risk #74)
•
Risk Identification: Common Mode Noise (Medium Risk)
If all the electrical noise sources, especially Common Mode Noise, are not dealt with early in
the project, it may drive the schedule during the I&T phase or, even, degrade the science
mission. The current requirement for Common Mode Noise is below the 100mVp-p.
•
Risk Mitigation:
–
Early identification of Common Mode Noise requirements and rigorous enforcement of
Common Mode Noise requirements through test.
–
Early assessment of potential Common Mode Noise source and victim by “Source-CouplingVictim” analysis.
–
Selective Spacecraft and Instrument ETU level test for potential Common Mode Noise
sensitive components (i.e. LVDS)
–
Robust Spacecraft grounding design
o Component grounding and bonding requirement of 2.5 milliohm.
o Build the spacecraft structure as a Faraday Cage to keep the external noise out
o Shield or filter external harnesses to protect from ESD induced Common Mode Noise
o Use of common mode chock on a DC/DC converter to minimize Common Mode Noise
–
Verification of the Common Mode Noise at the Spacecraft level I&T at the Common Mode
Noise critical interfaces
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 21
Document Status
Documents
Due Date
Status
Elec. Sys. Spec. :
CCB (02/12/04)
approved
Power Distribution List:
CCB (01/21/04)
approved
S/C Fuse Analysis (preliminary):
Peer PDR
released
Voltage Drop Analysis (preliminary):
Peer PDR
released
Electrical Interface List (preliminary):
Peer PDR
released
Parts and Material List (rev 2):
Mission PDR
in review
Spacecraft Harness ICD (preliminary):
Mission PDR
In review
S/C Electrical Block Diagram (draft):
Peer PDR
released
S/C Grounding Diagram (draft):
Peer PDR
released
EGSE Grounding Diagram (draft):
Mission PDR
In review
S/C & EGSE Grounding Diagram (draft):
Mission PDR
In review
Electrical Systems ICD (draft):
Aft Mission PDR
In review
FlatSat Electrical Block Diagram (draft):
Aft Mission PDR
In review
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 22
Harness Design & Development Schedule
Subsystem & Element
CY 2003
Q4
CY 2005
CY 2006
CY 2007
CY 2008
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
4/8
8/03
2/05
3/04 5/04
CY 2004
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
LAUNCH
MISSION MILESTONES
SRR/
SCR
Electrical Systems
PDRCR
ICR
12/4/03
CDR
PER
1/20/05
CDR
PDR
PSR
1 = Spacecraft Integration
= Schedule Reserve
2 = Instrument Integration
3 = Environmental Testing
4 = Launch Site Operations
Flatsat Harness & EGSE Harness
Design
Parts Buy
Fab
Integ &Test
Flatsat Support
Spacecraft Flight Harness
Design
Parts Buy
Fab & Test
Bake out
S/C I&T Support
Inst. I&T Support
T/V & RF Test Harness
Design
Parts Buy
Fab & Test
Environmental Test
Spacecraft I&T
1
SDO Preliminary Design Review (PDR) – March 9-12, 2004
2
3
4
Launch
Electrical Page 23
Conclusion
•
Documented Electrical Systems Requirements in 464-ELEC-SPEC-0004
•
Identified and documented Subsystems and Instruments Electrical Interface
•
Developed a Power Distribution
•
Identified Majority of Signal Interfaces
•
Provided S/C Charging and Discharging requirements
•
Provided EMI/EMC requirements
•
Provided Grounding requirements and methods
•
Developed Harness Design and Manufacturing Approach
•
Defined Verification Approach
•
Risk Identified and Mitigation being Implemented
•
Closing Action Items and RFAs
•
Completed Documentations for PDR
•
READY TO PROCEED TO DETAIL DESIGN
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 24
Back-Up
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 25
To Unswitched
Bus
SDO Preliminary Design Review (PDR) – March 9-12, 2004
FET #6
15 A
FET #5
15 A
FET #4
5A
FET #3
5A
FET #2
5A
FET #1
5A
PSE DM (TBD)
Unswit #2
Unswit #1
SSPC #8
5A
SSPC #7
5A
SSPC #6
10 A
SSPC #5
10 A
SSPC #4
10 A
SSPC #3
10 A
SSPC #2
10 A
SSPC #1
15 A
PSE OM #6
Unswit #2
Unswit #1
SSPC #8
5A
SSPC #7
5A
SSPC #6
10 A
SSPC #5
10 A
SSPC #4
10 A
SSPC #3
10 A
SSPC #2
10 A
SSPC #1
15 A
PSE OM #5
Unswit #2
Unswit #1
SSPC #8
5A
SSPC #7
5A
SSPC #6
10 A
SSPC #5
10 A
SSPC #4
10 A
SSPC #3
10 A
SSPC #2
10 A
SSPC #1
15 A
PSE OM #4
1A
1A
1A
Ka Transmitter-A
[ Spare ]
S-band Receiver-A
2A
2A
2A
2A
1A
1A
GCE-A LPSC & PCC (to Page 1)
Pyro Valve NO-B Power (to EVD B)
Pyro Valve NC-B Power (to EVD B)
HGAS -Z Deploy-B Power
HGAS +Z Deploy-B Power
S/A -Y Deploy-B Power
S/A +Y Deploy-B Power
[ Spare ]
[ Spare ]
Prop Lower Support Heater #1B
EVE
HMI-B
HMI-A
Instrument Decontam Heater Bus-B
AIA-B
AIA-A
EVD-B Drive Power
C&DH-B PCC
S-band Receiver-B
ACE-A PCC ( to Page 1)
Ka Transmitter-B
[ Spare ]
Instrument Survival Heater-B
GCE-B LPSC & PCC
Reaction Wheel #4
1A
1A
1A
1A
1A
1A
1A
2A
1A
2A
2A
2A
2A
2A
Reaction Wheel #3
1A
1A
1A
1A
1A
1A
1A
2A
1A
2A
2A
2A
2A
2A
EVD-A Drive Power
S-band Comm Card-A (to Page 1)
1A
1A
S/C Bus Survival Heater-B
2A
2A
2A
2A
2A
2A
2A
2A
1A
ACE-B LPSC & PCC
Reaction Wheel #2
Reaction Wheel #1
C&DH-B LPSC
SW #15: Optical Bench Heater #7B
SW #16: Optical Bench Heater #8B
SW #14: Optical Bench Heater #6B
SW #13: Optical Bench Heater #5B
SW #12: Optical Bench Heater #4B
SW #10: Optical Bench Heater #2B
SW #11: Optical Bench Heater #3B
SW #8: [Spare]
SW #9: Optical Bench Heater #1B
SW #6: [Spare]
SW #7: [Spare]
SW #5: [Spare]
SW #3: - HGA Gimbals (Azimuth)
SW #4: - HGA Gimbals (Elevation)
SW #1: + HGA Gimbals (Azimuth)
SW #2: + HGA Gimbals (Elevation)
GCE-B LPSC & PCC from
PSE-A (from Page1)
SW #15: +Z HGAS Damper HTR-B
SW #16: -Z HGAS Damper HTR-B
SW #14: -Y S/A Damper HTR-B
SW #12: [Spare]
SW #13: +Y S/A Damper HTR-B
SW #10:Prop External HTR Power #1B
SW #11:Prop External HTR Power #2B
SW #9: Prop Line HTR-B
SW #8: Prop Upper Support HTR-B
SW #6: S-Band Transmitter-B
SW #7: Prop Lower Support HTR #2B
SW #5: S-Band Transmitter-A
SW #3: SBC & Bulk Memory-A
SW #4: SBC & Bulk Memory-B
SW #2: Ka Comm Card-B
SW #1: Ka Comm Card-A
C&DH-B PCC from PSE-A
(from Page1)
SW #15: [Spare]
SW #16: [Spare]
SW #14: [Spare]
SW #12: RW Command Drive Power
SW #13: [Spare]
SW #10: Pressure X-ducer Power #2
SW #11: IRU Command Drive Power
SW #8: [Spare]
SW #9: Pressure X-ducer Power #1
SW #6: Iso Valve Open Drive Power
SW #7: Iso Valve Close Drive Power
SW #5: Star Tracker #2
SW #3: IRU #3
SW #4: Star Tracker #1
SW #1: IRU #1
SW #2: IRU #2
ACE-B PCC from PSE-A
(from Page1)
Power Distribution Diagram , Page 2
Note : Default state of all SSPC’s are TBD.
GCE-B PCC
GCE-B
C&DH-B PCC
C&DH-B
ACE-B PCC
ACE-B
SDO Power Distribution Diagram (‘B’ Side)
Power Distribution (B Side)
Electrical Page 26
Harness Design (Cont’d.)
•
Part and Material Selection
(Cont’d.)
– D Backshell: Shot sleeve lightweight
Aluminum
MDM-BACKSHELL
ACHTUNG !
SCHUTZVERMERK NACH DIN 34 BEACHTEN
AttentionCopyright by Dowatronic Sommer GmbH&Co KG
DW 214-xx-1-6-00yy
DW-364-37-6-6-0254
xx = 9/15, 12/26, 25/44,
37/62, 50/78, or 104
DW-364-25-4-6-0250
DW-364-21-3-6-02XX
y = 11, 12, 13, 14, 15, or 16
– The proposed EMI backshell, by
DOWATRONIC, is a split-piece
backshell made of non-magnetic
Aluminum plated with either Nickel or
Gold over Nickel.
DW-364-15-2-6-0256
DW-364-09-1-6-0248
BACKSHELLS FOR
SUBMINIATURE
D-CONNECTORS
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 27
Harness Design (Cont’d.)
SDO Preliminary Design Review (PDR) – March 9-12, 2004
Electrical Page 28