Thermal

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Section 16 Thermal
Nicholas M. Teti EO-1 Thermal Systems Lead,
Swales Aerospace
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Contents

• Thermal Control System
• Performance Summary
• Thermal Analysis
• Thermal Balance Thermal Vacuum Testing
• Verification Matrix
• Configuration Changes
• RFA Status
• PR Status
• Report Status
• Residual Risk Items
• Readiness Statement

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Thermal Control System

• Passive Radiators
• Used on Spacecraft Equipment Panels 1, 2, 4 and 6
  to radiate excess heat to space and maintain
  overall bulk temperature of spacecraft
• REGULATED CONDUCTIVE PATHS
• G-10 Isolators between Equipment (Battery) Panel
  3 and S/C Structure
• Maintain Battery 185C
• G-10 Isolators between PPT Mounting Plate and
  Panel 6
• Louvers
• Used to Regulate Battery Equipment Panel 3
  Temperature
• TRMM spare with 10C Design (5-15C) -
  calibrated by OSC

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Thermal Control System

• Multi-Layer Insulation (MLI)
• Built by Swales Aerospace
• 3 mil on Zenith Deck Equipment Panels
• 2 mil on Nadir Deck and HEA/CEA boxes
• Black Kapton on Nadir Deck below ALI FPA
  Radiator
• Battery Bay Enclosure - Aluminized Kapton
• Propulsion Tank
• Thermal Coatings
• Aeroglaze A276 White Paint
• Zenith Deck S-Band Antenna and SADA Actuator
  Cover
• Aeroglaze Z306 Black Paint
• Used on Nadir Deck S-Band Antenna

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Thermal Control System

• Carbon Carbon Radiator (CCR)
• Six Thermistors
• PSE and LEISA Electronics
• Pulse Plasma Thruster (PPT)
• G-10 Isolators between PPT Mounting Plate and
  Panel 6
• Lightweight Flexible Solar Array (LFSA)
• G-10 Isolators between LFSA Electronics Box and
  Zenith Deck
• 2-mil Kapton on External LFSA Electronics Box
• Autonomous Star Tracker (AST)
• Design Verification during TB Testing
• Reduced Radiator Size w/ MLI added to Sun Shade
  and AST Body

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Thermal Control System

• Thermostatically Controlled Survival Heaters
• Used to maintain components above cold survival
  limits
• Primary and Secondary Circuits
• Redundant Thermostats
• Heater Sizing
• Science Mode lt 5 watts
• SafeHold Mode lt 20 watts
• CHOTHERM between electronic boxes and S/C
  Equipment Panels
• High emissivity coatings are used to enhance
  internal radiation

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Thermal Control System

• Calorimeters
• Bracket mounted with mass simulators for TB and
  TV Testing
• Flight units not available for TB / TV Test
• Flight units delivered to project 3/8/00
• Z93 White Paint (GSFC)
• LA-II White Paint (AZ Technology)
• Propulsion Tank
• MLI blanket fabricated and installed
• Heater Verification completed during TV testing

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Thermal Control System

• ALI
• Maintain 200K Passive Radiator for Focal Plane
  Assembly
• Black Kapton On Nadir Deck in Front of FPA
  Radiator
• Passive Radiator for Focal Plane Electronics
• ALICE Box conductively coupled to Instrument
  Pallet which is conductively coupled to the EO-1
  Nadir Deck
• Hyperion
• HSA Conductively Isolated from Spacecraft Nadir
  Deck
• CEA/HEA are Thermally Coupled to the Spacecraft
  Nadir Deck
• Atmospheric Corrector
• MLI Blanket Provided by Swales
• Conductively mounted to Spacecraft Nadir Deck

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Instrument Thermal Requirements

• Advanced Land Imager (ALI) Interface
• No thermal isolation between Instrument Shroud
  Instrument Pallet
• No thermal isolation between Instrument Pallet
  and S/C Nadir Deck
• Bolted Interface
• DeltaT 10C to 20C between Nadir Deck and
  Instrument Interface
• Hyperion Interface
• Energy transferred from Hyperion Instrument
  Mounting Plate to the Nadir Deck shall be
  regulated to maintain the Nadir Deck upper limit
  temperature below 40C during all phases of the
  mission.
• NMP Technology Interface
• Energy Transfer at Spacecraft Interface /- 5
  watts

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Thermal Analysis
ALI FPA Radiator
Bay 4 Radiator
Thermal Models updated and correlated based on
spacecraft Thermal Balance Test Results. No
significant changes required.
Louver
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Thermal Design Verification
Predictions vs. Design Maximum
DCE Orbit - Hot Case
Model Correlation
TC Thermocouple
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Thermal Design Verification (continued)
Predictions vs. Design Minimum
SAFEHOLD - Cold Case
Model Correlation
TC Thermocouple
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Thermal Design Verification Summary

• Thermal Balance Test
• Critical spacecraft components within 5C of
  thermal model predictions
• Thermal design goals met with margin
• Radiator areas verified
• NiCd Battery thermal design verified
• Autonomous Star Tracker thermal design verified
• ALI instrument performed as designed
• Hyperion instrument performed as designed
• Atmospheric Corrector instrument performed a
  designed
• NMP Technologies performed as designed

TC Thermocouple
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Thermal Verification Plan
EO-1 Verification Plan (SAI-SPEC-158) and
Environmental Specification

• Thermal-vacuum testing of protoflight and flight
  components and spares shall be performed to
  demonstrate satisfactory operation in
  representative functional modes at mission
  operating temperatures, at temperatures in excess
  of the extremes predicted for the mission, and
  during temperature transitions. Protoflight
  components shall be tested in a non-operational
  mode at cold and hot limits to demonstrate that
  permanent degradation will not result from
  exposure to survival mode temperatures defined
  for the EO-1 mission. In addition, for
  components able to be powered at low temperature
  survival heater settings, the protoflight and
  flight units shall be tested in a powered mode to
  demonstrate operation without degradation,
  although the component need not meet its
  performance specification until the operational
  test limit is reached.
• Components shall be subjected to a minimum of 4
  hot-cold cycles with the hot temperature at 10C
  above the maximum operating predictions and the
  cold temperature 10C below the minimum operating
  predictions. Where the temperature of an area is
  controlled by a verified active thermal control
  system (such as thermostatically controlled
  heaters), the margin may be reduced to 5C.
• The test duration shall be based on the time
  required to perform performance/functional
  testing of the component at each hot and cold
  temperature plateau but, as a minimum, two-hour
  soak periods shall be conducted. Components
  shall be operated during the transition times and
  turn-on demonstrations shall be made at both cold
  and hot extremes.
• Components that are powered during the Delta II
  vehicle launch phase shall be operated during
  test chamber pump down and venting to ambient to
  verify performance.

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Spacecraft Level Testing

• Spacecraft Level
• Four cycles of Thermal Vacuum Testing
• Thermal Balance Test
• Hot Balance (Data Collection Event)
• Cold Balance (Safe Hold)
• Cold Balance (Standby)
• Spacecraft thermal control system performed
  nominally
• Post Test Correlation within 5C
• Spacecraft Hardware
• Thermal Louver calibrated by OSC
• Heaters are NASA Standard Parts (S-311-79)
• Thermostats are NASA Standard Parts (S-311-429)
• Thermistors are NASA Standard Parts (S-311-P18)
• Heater/Thermostat Circuits
• Verified using CO2 cold spray during IT
• Verified during Thermal Vacuum Testing

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Thermal Requirements
5C
40C
Qualification Test Limits (Operating)
Heater Controlled
- Set to 5C for primary heater circuits having
gt75 duty cycle
35C
5C
Acceptance Test Limits
30C
10C
Flight Prediction/Design Range
Operational Heater Control (includes safehold)
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(No Transcript)
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Box Level Testing
Safehold
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Instrument Level Testing

• Advanced Land Imager
• Four operating cycles One survival cycle of TV
  Testing
• Thermal Balance Test Analysis for ALICE Box
• Hyperion
• Four operating cycles One survival cycle of TV
  Testing
• Thermal Balance Test at nominal hot and cold
  operating temperatures
• Atmospheric Corrector
• Four survival cycles of TV Testing
• Four operating cycles

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Verification Matrix
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Accumulated Power On Time for EO-1 S/C
Components
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Post TV/TB Test Configuration Changes

• Equipment Panel 1 Radiator
• Reduced radiator size to decrease heater power
  duty cycle
• Replaced Nadir Deck Heaters
• Autonomous Star Tracker
• Prior to TB/TV spacecraft testing, radiator size
  was modified to correct error in vendor modeling
  and design
• Added Multi-Layer Insulating blankets around
  entire AST shade

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Technical Peer Reviews

• PDR, CDR, Confirmation Review
• Thermal Peer Review (6/98)
• Delta-Thermal Critical Design Review (10/21/98)
• Thermal Subsystem Readiness Review (9/24/99)
• Pre-Environmental Review (10/1/99)
• Pre-Ship Review (12/15/99)
• No Open RFAs as a result of Reviews

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Mission CDR RFAs

• RFA 4.31
• Perform transient spacecraft thermal analysis for
  all EO-1 mission modes.
• Thermal Analysis Complete for Launch, Ascent,
  DCE, Standby and Safemode
• RFA 4.33
• Perform thermal design and analysis of solar
  array deployment mechanisms, including HOP
  restraint/release, dampers and hinges.
• Thermal analysis completed for HOPS and Dampers.
  The HOPS are contained in an MLI enclosure. The
  dampers have thermostatically controlled heaters
  and are enclosed with MLI.
• RFA 4.34
• Integrate reduced thermal mathematical model of
  the ALI in SINDA format into the spaceraft
  mathematical model and perform integrated
  analysis.
• The ALI, Hyperion, Atmospheric Corrector and NMP
  technologies have been integrated with the
  spacecraft models and analyzed.

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S/C CDR RFA 4.36

• Consider providing a breadboard to the IRU vendor
  for demonstration of the 1/4 C temperature
  control stability
• Background
• At the time of the S/C CDR, the temperature
  control of the gyro internal platform was to be
  hosted on the S/C side of the interface
• Within a month later, Litton GC, the IRU vendor,
  accepted an ICD change in this regard since an
  internal heater control module had been developed
  for another program and was already to be
  included in the SIRU design used by EO-1
• Response to RFA
• Due to the change an the IRU ICD, the concern
  raised by the RFA was retired and no breadboard
  was needed by Litton GC
• IRU temperature stability based on the input bus
  voltage only was verified during IRU Acceptance
  Testing and continues to be verified during S/C
  IT as part of IRU performance tests

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PSR RFA Status

• RFA 14.22
• Completed
• RFA 14.23
• Completed
• RFA 14.24
• Completed

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RFA 14.22

• SPECIFIC REQUEST Provide or include in the
  January PSR a temperature sensitive component
  tabular listing which included the following
  information
• Thermal design minimum / maximum power
  dissipation range
• Actual measured/derived power dissipation
• Hot / Cold /Safehold thermal correlation
  temperature differences
• Demonstrated heater margins
• SUPPORTING RATIONALE This information is
  normally contained in a Pre-Ship Review Package.
• PROJECT RESPONSE
• A chart was presented showing the thermal design
  min/max power dissipations provided by the EO-1
  spacecraft systems.
• A spreadsheet showing the transient measured
  power for the EO-1 electronics that was verified
  during thermal balance and thermal vacuum
  testing. The only change was for the SADA during
  Safehold. The SADA dissipation remains 11.86
  during safehold. In addition, 1 watt power loss
  was added to the cable wrap during the sunlit
  portions of the mission
• Correlated Data was provided for Hot DCE Orbit,
  Cold Standby and Safehold Cold Thermal Balance
• Heater Duty Cycles provided.

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RFA 14.22
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RFA 14.23

• SPECIFIC REQUEST Provide or include in the
  January PSR a component tabular listing which
  includes the following information
• Temperature requirements
• Flight Cold and Hot temperature predicts
• Qualification test history for each temperature
  sensitive component.
• Distinguish between subsystem and observatory
  testing and provide information in terms of
  temperatures achieved and number of cycles.
• SUPPORTING RATIONALE This information is
  normally in a Pre-Ship Review Package.
• PROJECT RESPONSE TO PSR RFA 14.23 Charts
  provided with requested data.

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RFA 14.23 (continued)
Predictions vs. Design Maximum
DCE Orbit - Hot Case
Model Correlation
TC Thermocouple
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RFA 14.23 (continued)
Predictions vs. Design Minimum
SAFEHOLD - Cold Case
Model Correlation
TC Thermocouple
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RFA 14.23 (continued)
Safehold
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RFA 14.23 (continued)
Heater Duty Cycle for DCE and Standby Cases -
Cold Bias
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RFA 14.23 (continued)
Heater Duty Cycle for Safehold Case - Cold Bias
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RFA 14.24

• SPECIFIC REQUEST Assure that adequate launch
  site thermal subsystem inspections occur prior to
  launch. Verify that the inspection process is
  sound.
• SUPPORTING RATIONALE Pre-Thermal-Vacuum Test
  inspections were not adequate since a test
  blanket hung up on the solar array actuator.
• PROJECT RESPONSE
• Nick Teti will be at launch site to perform final
  inspection of the thermal control subsystem. In
  addition to items identified in SAI-PROC-757,
  EO-1 Satellite Red Tag Item Removal and
  Installation Procedure, a Work Order
  Authorization (WOA) will be written to identify
  all remaining closeouts for the EO-1 thermal
  control systems, this includes but is not limited
  to, blanket closeouts, louver installation, final
  taping. WOAs are reviewed and verified by the
  appropriate personnel.
• The test blanket interference during thermal
  vacuum was a unique configuration that will NOT
  be part of the launch configuration. A camera was
  placed at the location of the solar array to
  monitor the movement within the blanket enclosure
  recognizing the possibility of interference.
  Several tests were run prior to the start of the
  thermal vacuum test to verify proper clearance.
  The camera provided an opportunity to monitor the
  solar array drive and if an anomaly were observed
  the solar array movement would be halted

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Report Status

• Thermal Balance / Thermal Vacuum Final Report
  (SAI-RPT-319)
• Completed
• Thermal Design and Analysis Final Report
  (SAI-RPT-322)
• 3/31/00
• Thermal Interface Control Document -
  (SAI-ICD-048, Rev B)
• 4/15/00

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Residual Risk Items

• None
• No Redbook candidates

PR Status

• No OPEN PRs

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Readiness Statement

• On-Orbit thermal model updated based on results
  of TB Testing
• Thermal Analysis Complete
• Launch/Ascent
• DCE
• Standby
• Safemode
• No Open PRs
• Blanket closeouts are to be completed prior to
  shipment
• Documents scheduled for completion prior to
  shipment
• THERMAL SUBSYSTEM IS READY FOR SHIPMENT !