HUBBLE SPACE TELESCOPE (HST)
ADVANCED CAMERA FOR SURVEYS (ACS)
THERMAL BALANCE/THERMAL VACUUM
TEST PLAN #3
Released
Document No. P-442-2796
May 19, 2001
ACS Thermal Vacuum / Thermal Balance
Test Plan, #3
Prepared by:
_________________________________
Kristina Montt de Garcia
Swales, ACS I&T
__________
Date
_________________________________
Teri Gregory
Jackson and Tull Thermal Engineer
__________
Date
_________________________________
Radford Perry III
Swales Contamination Engineer
__________
Date
_________________________________
Rich Brewster
Ball Software/Operations Engineer
__________
Date
Reviewed by:
_____________________________
Mark Erickson
Ball I&T Manager
___________
Date
______________________________
John Meadows
Ball Quality Assurance Manager
__________
Date
______________________________
Chuck Harguth
Ball ACS Software Operations Lead
__________
Date
______________________________
Tim Schoenewiess
Ball ACS Electrical Lead
__________
Date
______________________________
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ii
Gregory Johnson
Ball Thermal Engineer
Date
______________________________
Beth Kelsic
Ball Contamination Engineer
__________
Date
____________________________
Jacqueline Townsend
HST Contamination Manager
__________
Date
______________________________
Thomas Toutsi
HST Quality Assurance Manager
__________
Date
____________________________
Robert Dedalis
HST Safety Manager
__________
Date
____________________________
George Hartig
STScI ACS Scientist
__________
Date
____________________________
Chris Skocik
ManTech Thermal Vacuum Test Engineer
__________
Date
Approved by:
_____________________________
Paul Volmer
Ball Aerospace, ACS Project Manager
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Date
_____________________________
Daniel Nguyen
HST Thermal Systems Manager
__________
Date
_____________________________
Doug Campbell
ManTech, GSFC Acting Instrument Manager
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Date
iii
1.0
INTRODUCTION ...........................................................................................................................................1
1.1
DESCRIPTION ..................................................................................................................................................1
1.2
TEST OBJECTIVES ...........................................................................................................................................1
1.2.1
General ..................................................................................................................................................1
1.2.2
Specific Objectives .................................................................................................................................1
1.3
TEST ITEM DESCRIPTION ................................................................................................................................2
1.4
TEST SETUP ....................................................................................................................................................2
2.0
TEST PERSONNEL ........................................................................................................................................2
2.1
3.0
REFERENCES.................................................................................................................................................4
3.1
3.2
4.0
TEST TEAM MEMBERS....................................................................................................................................2
APPLICABLE DOCUMENTS ..............................................................................................................................4
ACRONYM LIST ..............................................................................................................................................5
TEST FACILITIES AND GROUND SUPPORT EQUIPMENT ................................................................8
4.1
GROUND SUPPORT EQUIPMENT ......................................................................................................................8
4.1.1
Mechanical Ground Support Equipment ...............................................................................................8
4.1.2
Thermal Balance Test Fixture ...............................................................................................................8
4.2
CABLES...........................................................................................................................................................8
4.2.1
Test Cables.............................................................................................................................................8
4.2.2
Grounding Cable ...................................................................................................................................8
4.3
ELECTRICAL GROUND SUPPORT EQUIPMENT ..................................................................................................8
4.3.1
Science Instrument Test System (SITS) ..................................................................................................8
4.3.2
Thermal Conditioning Units ..................................................................................................................8
4.3.3
Monitoring Equipment ...........................................................................................................................8
4.4
CHAMBER 225 ................................................................................................................................................9
4.5
RAS/CAL........................................................................................................................................................9
4.6
CORONAGRAPHIC SPOT BACKLIGHT ...............................................................................................................9
5.0
INSTRUMENTATION ...................................................................................................................................9
5.1
THERMAL SENSORS ........................................................................................................................................9
5.1.1
Flight Sensors ........................................................................................................................................9
5.1.2
Test Thermocouples ...............................................................................................................................9
5.1.3
Test Thermistors ....................................................................................................................................9
5.2
HEATERS ........................................................................................................................................................9
5.2.1
Test Heaters .........................................................................................................................................10
5.2.2
Flight Heaters ......................................................................................................................................10
5.3
THERMO-ELECTRIC QUARTZ CRYSTAL MICROBALANCES ............................................................................10
5.4
CHAMBER CONVECTRON ..............................................................................................................................10
5.5
ACS CONVECTRON GAUGE ..........................................................................................................................10
5.6
MICRO-ION GAUGE ......................................................................................................................................11
6.0
TEST TOLERANCES AND SPECIFICATIONS .......................................................................................11
7.0
CLEANLINESS AND CONTAMINATION MONITORS ........................................................................11
7.1
CHAMBER AND CLEAN TENT VERIFICATION (AMBIENT) ..............................................................................11
7.2
ACS PURGE ..................................................................................................................................................11
7.3
GSE/CHAMBER PRE-TEST OUTGASSING CERTIFICATION ..............................................................................12
7.3.1
Pre-Test Outgassing Set-Up ................................................................................................................12
7.3.2
Outgassing Certification ......................................................................................................................12
iv
7.4
ACS TV TEST SET-UP ..................................................................................................................................12
7.4.1
TB/TV Test Set-Up ............................................................................................................................... 12
7.4.2
Outgassing Measurements ...................................................................................................................13
7.5
CHAMBER BREAKS .......................................................................................................................................13
7.6
TEST COMPLETION .......................................................................................................................................13
8.0
THERMAL TEST PLAN ..............................................................................................................................13
8.1
GENERAL ......................................................................................................................................................13
8.2
PRE-TEST CHAMBER/GSE OUTGASSING CERTIFICATION ..............................................................................13
8.3
THERMAL BALANCE .....................................................................................................................................13
8.3.1
Cold Safe Thermal Balance, TB#1 ......................................................................................................14
8.3.2
Cold Operation Thermal Balance, TB#2 .............................................................................................14
8.3.3
Cold Anneal Thermal Balance, TB#3 ..................................................................................................14
8.3.4
Hot Operation Thermal Balance, TB#4 ............................................................................................... 14
8.3.5
MAMA On, HRC Off at Hot Operation, TB#5 .....................................................................................14
8.4
THERMAL VACUUM ......................................................................................................................................14
8.5
INSTRUMENT CALIBRATION ..........................................................................................................................15
8.5.1
Basic Detector Properties ....................................................................................................................15
8.5.2
Charge Transfer Efficiency (CTE) .......................................................................................................15
8.5.3
Detector Features ................................................................................................................................ 15
8.5.4
Dark Structure .....................................................................................................................................15
8.5.5
Image Stability .....................................................................................................................................15
8.5.6
Internal Calibration System Verification .............................................................................................15
8.5.7
Flatfield Uniformity .............................................................................................................................15
8.5.8
Flatfield Stability .................................................................................................................................16
8.5.9
SBC Flats .............................................................................................................................................16
8.6
OUTGASSING CERTIFICATION ........................................................................................................................16
9.0
THERMAL TEST PROCEDURE ...............................................................................................................16
9.1
INSTALLATION OF THE TEST EQUIPMENT INTO THE TV CHAMBER FOR THE PRE-TEST CERTIFICATION ........16
9.1.1
Configure the TBF for Pre-Test Certification: ...................................................................................16
9.2
PRE-TEST GSE/CHAMBER OUTGASSING CERTIFICATION ..............................................................................17
9.2.1
Outgassing Certification Case .............................................................................................................18
9.2.2
Return From Pre-Test Certification to Ambient ..................................................................................18
9.3
INSTALLATION OF ACS AND THE TEST EQUIPMENT INTO TV CHAMBER 225 ................................................18
9.3.1
Set up SITS ...........................................................................................................................................18
9.3.2
Configure ACS for Test ........................................................................................................................18
9.3.3
Install ACS into the TBF ......................................................................................................................19
9.4
THERMAL BALANCE .....................................................................................................................................21
9.4.1
Ambient ................................................................................................................................................21
9.4.2
Vacuum Acquisition .............................................................................................................................21
9.4.3
Cold Safe - Thermal Balance #1 ..........................................................................................................22
9.4.4
Cold Operation - Thermal Balance #2 ................................................................................................ 22
9.4.5
Cold Anneal - Thermal Balance #3 .....................................................................................................24
9.4.6
Hot Operation - Thermal Balance #4 ..................................................................................................25
9.4.7
MAMA “On” Sensitivity at Hot Operation Thermal Balance .............................................................27
9.5
THERMAL VACUUM ......................................................................................................................................28
9.5.1
Transition to Hot Soak #1 ....................................................................................................................28
9.5.2
Hot Soak #1 .........................................................................................................................................28
9.5.3
Transition to Cold Soak #1 ..................................................................................................................28
9.5.4
Cold Soak #1 (with cold start side 1.) ..................................................................................................29
9.5.5
Transition to Hot Soak #2, Functional Test .........................................................................................29
9.5.6
Hot Soak #2, Functional Test ..............................................................................................................29
9.5.7
Transition to Cold Soak #2, Functional Test .......................................................................................31
v
9.5.8
Cold Soak #2, Functional Test (with cold start side 2) ........................................................................32
9.5.9
Transition to Calibration .....................................................................................................................32
9.5.10 Calibration ...........................................................................................................................................32
9.5.11 Transition to the Outgassing Certification ..........................................................................................33
9.5.12 Outgassing Certification ......................................................................................................................33
9.6
TRANSITION TO AMBIENT TEMPERATURE.....................................................................................................33
9.7
CHAMBER BACKFILL, AMBIENT ABBREVIATED FUNCTIONAL TEST ..............................................................34
9.8
TEST END .....................................................................................................................................................34
10.0
10.1
10.2
11.0
11.1
11.2
11.3
12.0
EMERGENCY CONDITIONS ....................................................................................................................34
OPERATIONAL HAZARD ANALYSIS (OHA) ...................................................................................................34
EMERGENCY PROCEDURES ...........................................................................................................................34
MEETINGS ....................................................................................................................................................35
SES CONFIGURATION BUY-OFF....................................................................................................................35
TEST COORDINATION MEETING ....................................................................................................................35
TEST READINESS REVIEW .............................................................................................................................35
GENERAL......................................................................................................................................................35
12.1 TEST FAILURE AND ANOMALY REPORTING...................................................................................................35
12.2 CONSTRAINTS ...............................................................................................................................................35
12.3 TEST PROCEDURE CHANGES.........................................................................................................................35
12.4 TEST SUCCESS CRITERIA ..............................................................................................................................35
12.4.1 Verification of Thermal Design ...........................................................................................................35
12.4.2 Verification of Thermal Analysis .........................................................................................................35
12.4.3 Verification of Electrical Performance ................................................................................................ 36
12.4.4 Verification of Flight Heaters ..............................................................................................................36
12.4.5 Verification of Calibration ...................................................................................................................36
12.4.6 Verification of Outgassing Requirements ............................................................................................36
13.0
SAFETY .........................................................................................................................................................36
13.1 SAFETY RESPONSIBILITY............................................................................................................................... 36
13.2 CAUTIONS/WARNINGS ..................................................................................................................................36
13.3 PRE-TASK BRIEFING .....................................................................................................................................36
13.4 SPECIFIC SAFETY PRECAUTIONS ...................................................................................................................36
13.4.1 Lifts ......................................................................................................................................................36
13.4.2 Purge ...................................................................................................................................................37
13.4.3 Ammonia ..............................................................................................................................................37
13.4.4 Electro-Static Discharge (ESD) ...........................................................................................................37
13.4.5 Fracture Critical Hardware ................................................................................................................37
13.4.6 Contamination .....................................................................................................................................37
vi
1.0 INTRODUCTION
This document describes the third ACS thermal vacuum test to be performed on the Advanced Camera for
Surveys (ACS).
1.1 DESCRIPTION
This test will be both a Thermal Balance, TB, test for model correlation and provide 2 full Thermal
Vacuum, TV, cycles to operate and calibrate the ACS under vacuum conditions with the instrument
exposed to its worse case thermal environments.
1.2 TEST OBJECTIVES
1.2.1
General
Verify the flight worthiness of the ACS Instrument.
Provide assurance that specified mission objectives will be met.
Verify the functional operation of the flight components at higher and lower than expected flight
temperatures thereby proving that there is design margin at the system level.
Verify the outgassing rate of the ACS.
1.2.2
Specific Objectives
Thermal
Perform two complete thermal vacuum cycles of the hardware with plateaus of at least 16 hours
each as required by STR-43.
Demonstrate system behavior with interfaces at 10C beyond the minimum and maximum
temperature excursions expected during the mission, where possible. At the temperature plateaus,
perform 2 cold starts (as required by STR-43) and functional tests of the ACS.
Demonstrate satisfactory operation of the ACS thermal control systems. This shall include
verifying thermal shelf heater control, thermistor operation and data acquisition, and heater
operation without the ASCS.
Validate and correlate the ACS thermal math model (TMM).
Contamination
Verify that the ACS meets the external HST outgassing rates and the internal ACS rates using
TQCMs throughout the test.
Calibration
Obtain SBC delta flats, totaling 10k e-/px, using internal D2 lamp, for filter F115LP.
Obtain a set of short exposure internal D2 flats through each of the remaining SBC filters/prisms to
estimate the count rates.
Obtain a set of 3600s SBC dark exposures to characterize dark rate vs MAMA tube temperature.
Monitor the Wide Field Channel (WFC) and High Resolution Channel (HRC) CCD performances
over the expected temperature range.
Perform image stability tests over a temperature range using the coronagraphic spot as a target on
HRC and the RAS/Cal point source as a target on the WFC.
1
Perform internal calibration system verification.
HAR Verification
Verify the fix for the apparent thermal short, HAR 1342.
Verify the calibration curve fix for the ACS-ASCS interface plate thermistor, HAR 1560.
Verify the fix for the apparent contamination seen on the SBC filter wheel, HAR 1282.
1.3 TEST ITEM DESCRIPTION
The Advanced Camera for Surveys will be configured in its flight configuration with WFC S/N 04 and
HRC S/N 01, and will be tested and calibrated under the extreme HST Aft Shroud environments predicted
for the life of the instrument. The ASCS double saddle will be installed in its flight configuration. The
Astronaut handhold will be installed. No L-Handle will be integrated and the vent covers will be removed.
A Micro-ion and a convectron gage will be mounted on a plate in place of the lower vent, viewing the
internal optics cavity of the ACS.
Figures 1-1 and 1-2 illustrate the ACS internal components and external enclosure features, respectively.
1.4 TEST SETUP
The ACS will be tested in Chamber 225, enclosed in the Thermal Balance Fixture, TBF, in square
configuration. This test fixture will consist of 23 heater controlled zones which will be set to simulate the
predicted HST Aft Shroud environment temperatures under each of the operational scenarios described in
Section 8 of this test plan. RAS/Cal and the coronagraphic spot Backlight will both be used as stimuli for
the ACS. The Backlight has one heater zone, the RAS/Cal has its own GSE for powering the heaters and
T/Cs.
2.0 TEST PERSONNEL
2.1 TEST TEAM MEMBERS
The HST project has the total responsibility for conducting this test. The responsibilities of the various test
positions are given below:
The Test Director (TD) is the project’s representative for the test and has the overall responsibility for
accomplishing the thermal test program outlined in this test plan. This individual is responsible for ensuring
that the planned procedures will maintain the health and safety of ACS and not cause any out-of-limit
conditions. This person shall have the authority to approve all changes to the thermal test procedures. The
TD is to conduct the test coordination meeting noted in Section 11.2 and is responsible for having a final
report of this test written, approved and issued.
The TD has the overall responsibility for the setup, configuration, test and tear down for the test. This
individual is responsible for the day to day activities necessary to maintain the test schedule and shall
approve all work orders associated with the test. Finally, the TD will participate in the resolution of
problems and the determination of any additional tests that may be required.
The Functional Test Conductors (FTCs) are responsible for writing Functional test procedures for the TV
test. All the procedures are to be fully tested before they are run during the TV tests. They are also
responsible for ensuring that the functional test procedures are followed and fully accomplished. They are
to approve all changes to the functional test procedure and to provide inputs to and attend the test
coordination meetings. They shall maintain a test log of all the operations, tests, activities, anomalies and
occurrences as they happen according to the 24-hour clock in the operations center. They shall also
2
maintain the master redlined copy of the ACS Functional Test procedure. The FTCs shall be responsible to
and report directly to the TD.
The Thermal Test Conductor (TTC) is responsible for ensuring the thermal test procedure is followed and
for completely accomplishing the tasks written therein. The TTC will declare when thermal balance and
thermal soak criteria has been met. This individual is also responsible for assuring that changes of the
thermal environment, including the test fixtures, will not jeopardize the health and safety of the ACS. The
TTC shall maintain a test log of all activities, operations, and anomalies as they happen according to the 24hour clock. This person shall approve all changes to the thermal test procedure and is to provide inputs to
and attend the test coordination meetings. The TTC shall also maintain the master redlined copy of the
thermal test procedure. The TTC shall be responsible to and report directly to the TD.
The Thermal Vacuum Test Engineer (TVTE) has the responsibility for the health and safety of the test
facility and has the sole authority to direct NSI Technology Services (NSI) for the operations of the 225
chamber. All directions and changes to chamber operation must go through this engineer who is
responsible to see that the facility is operated as defined by the test procedure or as modified by the daily
coordination meeting. The TVTE is to provide inputs to and attend the coordination meetings. Generally,
the TVTE will work closely with the TTC. The TVTE is responsible for producing the ACS TB/TV Test
Procedure and shall be consulted by the TTC before any changes to the thermal test procedure are
approved.
Quality Assurance (QA) personnel are responsible for the safety of the ACS and for verifying that all
testing, as well as contamination control activity, is accomplished per approved procedures through the
Work Order Authorization (WOA) system. The QA representative shall initial and date all redline changes
to the test procedures as approved by the TD, FTC and TTC. They shall assure that the calibration of the
test equipment is up-to-date, and all anomalies are documented on the Problem Record Sheet. QA shall
also assure that there is an accurate file maintained of all the as-run test procedures performed during this
test. QA personnel shall report any nonconformance to the TD and attend the daily meetings.
The Contamination Control Engineer (CCE) is responsible for obtaining, analyzing and verifying all of
the contamination control data for this test. The CCE is also responsible for assuring that the test
operations, procedures and activities shall not cause undue contamination of ACS or any of its components.
The ACS Test Conductors (TCs) are responsible for the generation and accumulation of all the test
procedures necessary to fulfill the objectives of the thermal and functional test plans. In addition, they are
responsible for directing the real time performance of the test in accordance with the master timeline. They
report directly to the FTC.
The Calibration Test Conductor decides what test to run, and is in charge of executing it. This person
works directly with the SITS operators to ensure that the correct exposures are being taken. The Calibration
Test Conductor needs access to one of the ACS computers to examine the data as it comes in.
The Data Logger/Computer Support person logs the data as it comes in, maintains the official log book,
makes two plots of each image and places them in the appropriate binders. This person also provides
computer support (system, IDL) in order to resolve any computer anomalies.
The Calibration Scientist #1 maintains the “summary log”, which will be more descriptive than the data
log in that it associates data frames with the tests that are being run. This person examines each image to
ensure that it meets with expectations and performs data reduction and analysis tasks. He/She also keeps
track of data analysis and reduction progress.
3
The Calibration Scientist #2’s primary task is data reduction and analysis. His/her tasks are assigned by
the calibration test conductor or lead calibration scientist.
3.0 REFERENCES
3.1 APPLICABLE DOCUMENTS
P-442-1526
ACS Basic Operations Overview
P-442-2034
RAS/Cal lifting and Handling Procedure
P-442-2118
Technical Operating Procedure for Axial Science Instrument Installation and Removal
To/From the Thermal Balance Fixture
P-442-2406
Procedure for the Use of Acs GALLOWS for Rotating the TBF
P-442-2482
ACS Mechanism Relay Test
P-442-2494
HST ACS Contamination Control and Implementation Plan
P-442-2609
ACS EICIT Procedure
P-442-2613
ACS System Functional Test Side 1
P-442-2614
ACS Aliveness
P-442-2616
ACS Abbreviated Functional
P-442-2617
ACS System Functional Test Side 2
P-442-2618
ACS Servicing Mission Functional Test (Ground Test Version)
P-442-2635
ACS IVT
P-442-2797
ACS Thermal Vacuum/ Thermal Balance Test #3 Procedure (Code 549 Test
Operations document)
P-442-TBD
ACS CARD/OLD
STR-29
Hubble Space Telescope Servicing Mission Contamination Control Requirements
STR-43
Performance Assurance Objectives for NICMOS and STIS
NASA GSFC
517510
Engineering Services Division Safety Manual, August 1991, Type II Fracture Critical
Handling
NSI 01-05-120
Anhydrous Ammonia Safety Operating Procedure
JSC-SN-C-0005
Contamination Control Requirements for the Space Shuttle Program
NHB5300.4(3L)
NASA Handbook Requirements for Electrostatic Discharge Control
MIL-STD 1246
Product Cleanliness Levels and Contamination Control Program
MIL-STD-1686
Electrostatic Discharge Control Program for Protection of Electrical and Electronic
Parts, Assemblies and Equipment
FED-STD-209
Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones
4
NSS/GO1740.9B Standard for Design Requirements for Lifting and Hoisting Equipment
3.2 ACRONYM LIST
ACS
Advanced Camera for Surveys
ASCS
Aft Shroud Cooling System
Amps
Amperes
ASI
Axial Science Instrument
ATTITUDE
ACS Thermal Telemetry Ingest Tool Used During Environmentals
C
Celsius
CARD
Constraints And Restrictions Document
CC
Contamination Control
CCD
Charge Coupled Device
CCE
Contamination Control Engineer
CCS
Control Center System
COSTAR
Corrective Optics Space Telescope Axial Replacement
CTE
Charge Transfer Efficiency
D2
Deuterium
e-
Electron
EGSE
Electrical Ground Support Equipment
EICIT
Electrical Interface Continuity/Isolation Test
ESD
Electrostatic Discharge
ft3
cubic feet
FTC
Functional Test Conductor
GALLOWS
Gravity Ameliorating Longitudinal-Lifting Omni-directional Work
Structure
GN2
Gaseous Nitrogen
GHRS
Goddard High Resolution Spectrograph
GSE
Ground Support Equipment
GSFC
Goddard Space Flight Center
HAR
Hubble Anomaly Report
5
HeNe
Helium Neon (LASER)
HP
Heat Pipe
hr
Hour
HRC
High Resolution Camera
HST
Hubble Space Telescope
HVPS
High Voltage Power Supply
Hz
Hertz
ICD
Interface Control Document
ID
Identification
IDL
Interactive Data Language
I/F
Interface
IPA
Isopropyl Alcohol
I&T
Integration and Test
IVT
Interface Verification Test
JSC
Johnson Space Center
LVPS
Low Voltage Power Supply
MAMA
Multi Anode Micro-channel Array
MEB
Main Electronics Boxes
MGSE
Mechanical Ground Support Equipment
MHz
Megahertz
MLI
Multi-Layer Insulation
N/A
Not Applicable
NHB
NASA Handbook
NICMOS
Near Infrared Camera and Multi-Object Spectrometer
NSI
NSI Technology Services Inc.
NVR
Non-Volatile Residue
OHA
Operational Hazard Analysis
OLD
Off-Load Device
Pa
Pascal
px
pixel
QA
Quality Assurance
6
RAS/Cal
Refractive Aberrated Simulator/Calibrator
RF
Radio Frequency
RGA
Residual Gas Analyzer
R/T
Real-Time
SBC
Solar Blind Camera
SI
Scientific Instrument
SITS
Scientific Instrument Test Set
SMS
Science Mission Specification
S/N
Signal to Noise
SSDIF
Space System Development and Integration Facility
SSM
Simulated Spacecraft Module
STIS
Space Telescope Imaging Spectrograph
STScI
Space Telescope Science Institute
TB
Thermal Balance
TBD
To Be Determined
TBF
Thermal Balance Fixture
TC
Test Conductor
T/C
Thermocouple
TCU
Thermal Control Unit
TD
Test Director
TEC
Thermoelectric Cooler
TMM
Thermal Math Model
TQCM
Thermoelectric Quartz Crystal Microbalance
TRR
Test Readiness Review
TTC
Thermal Test Conductor
TV
Thermal Vacuum
TVTE
Thermal Vacuum Test Engineer
UV
Ultraviolet
VCHS
Visibly Clean Highly Sensitive
VCHS+UV
Visibly Clean Highly Sensitive using Ultra Violet Light as an aid, See
SN-C-0005
7
W
Watts
WFC
Wide Field Camera
WOA
Work Order Authorization
4.0 TEST FACILITIES AND GROUND SUPPORT EQUIPMENT
4.1 GROUND SUPPORT EQUIPMENT
4.1.1
Mechanical Ground Support Equipment
The ACS will be installed in the facility 225 chamber. The chamber shrouds and TBF will be used
to simulate the HST aft shroud environments. All mechanical ground support equipment (MGSE)
used to lift, hold, or support, the ACS must be subjected to a stress and stability analysis. A
detailed description of this equipment is included in P-442-2118, Technical Operating Procedure
for Axial Science Instrument Installation and Removal To/From the Thermal Balance Fixture, and
in P-442-2406, Procedure for the Use of GALLOWS to Rotate the TBF.
4.1.2
Thermal Balance Test Fixture
The TBF will hold the ACS during the TB/TV tests and will provide the required thermal
environments for the instrument. The fixture will have 6 temperature controlled zones (23 circuits)
which will simulate the Aft Shroud environments predicted over the life of the ACS. Figures 4-1
through 4-3 show the fixture heater circuits and thermocouple locations. The TBF will be in
Square configuration, on 3 kinematic mounts on the TBF TV Support Plate.
4.2 CABLES
4.2.1
Test Cables
A listing of the test cables required for this test are presented in Table 4-1 and Figures 4-4 and 4-5.
4.2.2
Grounding Cable
This cable, located at the chamber payload cart, will be used to ground the ACS instrument while it
is in the chamber. There is also an external ground cable (several hundred feet in length) which
will be used when moving the payload to/from the chamber.
4.3 ELECTRICAL GROUND SUPPORT EQUIPMENT
This section itemizes the payload EGSE required for the test.
4.3.1
Science Instrument Test System (SITS)
SITS is a set of standalone computers which electrically simulate the HST Observatory and
Ground System for operation of the ACS.
4.3.2
Thermal Conditioning Units
TCU’s are designed to produce and maintain a wide range of temperatures during TB/TV tests. A
TCU will be used to control the temperature of the 2 TQCMs viewing the ACS aft vents during the
ACS TB/TV test.
4.3.3
Monitoring Equipment
The ACS TB/TV test data will be collected via three data acquisition systems as follows.
4.3.3.1
Flight Data
The ACS flight thermistor data will be collected and displayed by the SITS.
4.3.3.2
Test Data
The ACS test thermistor data will be collected and viewed via a Labview workstation.
8
4.3.3.3
GSE Data
The chamber shroud, TBF, test thermocouples, and the RAS/Cal and Backlight
thermocouple temperatures will be recorded and stored by the facilities data acquisition
system. Hard copies of the tabular and graphical test data are made at least on an hourly
basis.
4.3.3.4
ATTITUDE
The ACS Telemetry Ingest Tool Used During Environmentals, ATTITUDE, is a
telemetry archive system which combines thermal telemetry from the above three
separate sources and combines them into one archive. Labview software can also be
used to display and plot telemetry points. The three sources of ACS thermal data are
CCS, which supplies all thermal data that comes through the flight data stream, the
thermal chamber data from the environmental system and the additional test thermistors
through an Aux. 2 cable. All three sources are samples at 60 second intervals and the
data is time stamped and placed in an archive for future reference.
4.4 CHAMBER 225
Chamber 225 will provide a clean environment for the ACS. There will be a class 10,000, top down flow
clean tent outside the chamber and the chamber will be certified clean. See Section 7 for more details.
4.5 RAS/CAL
The RAS/Cal will be used for testing the ACS WFC. It will be aligned to the WFC and illuminated with the
HeNe laser through a fiber optics cable and vacuum feed-through.
4.6 CORONAGRAPHIC SPOT BACKLIGHT
The Backlight will provide a diffuse light source behind the coronagraphic spot so that any motion of the
optical bench can be monitored, if present. It will also be used for SBC flats. This has 1 heater zone (1
circuit) and 1 monitoring T/C.
5.0 INSTRUMENTATION
5.1 THERMAL SENSORS
5.1.1
Flight Sensors
The ACS flight thermistors, which will monitor the on-orbit instrument temperatures, are listed in
Table 5-1. This table lists each flight thermistor along with its yellow and red action limits, its
acceptance limits and its cold safe and hot operate temperature predictions. The locations of these
thermistors are illustrated in Figures 5-1 through 5-5.
5.1.2
Test Thermocouples
Thermocouples shall be installed on the test fixture and GSE as listed in Table 5-2. Their
individual locations are illustrated by Figures 4-1 through 4-3, as referenced in Table 5-2. There
are approximately 50 data thermocouples required for this test; TBF has 41, Backlight has 1, and
RAS/Cal has 8. All TBF and Backlight data thermocouples, control thermocouples and heaters
will be installed and connected to the TBF junction box. The proper performance of each T/C
shall be verified prior to fixture MLI blanket installation.
5.1.3
Test Thermistors
Test thermistors will be installed on ACS as illustrated in Figures 5-1 through 5-5 in order to
further instrument the TB/TV test and assist in the correlation of the ACS TMM. These
thermistors are listed in Table 5-3 with their corresponding action and acceptance temperature
limits and their cold safe and hot operate temperature predictions.
5.2 HEATERS
9
5.2.1
Test Heaters
Temperature controlled test heaters will be used to maintain the desired temperature of each
thermal zone on the TBF for each of the settings listed in Table 5-4. Each circuit will use one
feedback control thermocouple and multiple reference thermocouples. The feedback
thermocouple is placed in close proximity to one of the Kapton film heaters to ensure a quick
response time and eliminate over temperature. The facility operators and project personnel will
observe the reference thermocouples. By monitoring the reference thermocouples and adjusting
the controller set points, heater zones will meet their respective target temperatures by eliminating
any steady-state errors.
The heater controllers are the PID feedback type. Temperature control is maintained using
continuous power output through the heater circuits.
5.2.2
Flight Heaters
Thermal Shelf
The temperature of the instrument optical bench compartment is stabilized by a thermal shelf. This
shelf maintains the fixed bench temperatures similar to the predecessor GHRS, COSTAR and STIS
instrument thermal designs. The shelf is shaped so that it sits above two sides of the bench and is
mounted to the enclosure. Isolation from this shelf to the inboard panels and aft bulkhead is
provided. The thermal shelf has six areas of heater control with four heaters per control zone.
Three zones of control are located on each side of the bench as shown in Figure 5-3. Table 5-5
lists the maximum power available for each of the ACS operational thermal shelf heaters, as well
as their temperature and power mnemonics. The heater controls for the thermal shelves are
identical to the STIS proportional controls. Proportional control means that power is dissipated
continuously but at a variable rate. This is in contrast to thermostatically controlled heaters that
provide a given time averaged dissipation by cycling on and off with a fixed output whenever on.
The controllers will maintain the thermal shelf at 20C  0.2C.
Anneal Heaters
A 100 W heater is located on the ACS thermal interface plate. This anneal heater will be required
to raise the temperature of the interface plate which in turn raises the WFC and HRC TEC hot side
temperatures. The temperature of the HRC window is raised by a 30 W heater which is located
near the window. For annealing, the TEC hot side temperatures must be -5C and the HRC
window heater will be set to 30C.
5.3 THERMO-ELECTRIC QUARTZ CRYSTAL MICROBALANCES
Three TQCMs are required for monitoring outgassing from the ACS. The 2 aft vent TQCMs are required
to operate at -20C and -65C. The third, located at the aperture is required to operate at -20C . The
location of the TQCMs will be directed by the CCE during test set-up.
5.4 CHAMBER CONVECTRON
A convectron measures pressures in the range from 1000 Torr to 1x10 -4 Torr. It has a 0 to 7 volt analog
output and operates between 4 and 50C. The convectron can be safely baked out at 150C provided it is
powered down. The convectron will be used to ensure that the chamber pressure is in a proper range to turn
on the ion gauge.
5.5 ACS CONVECTRON GAUGE
The Convectron gauge measures pressures in the range from 100 Torr to 1 x 10 -4 Torr. The Convectron
gauge has an operating temperature range between 4oC and 50oC. The gauge itself operates as a
temperature-compensated, null-balance measurement device. Due to the changes in convective heat
10
transfer, the hot-wire filament changes temperature and resistance. The controller continuously adjusts the
voltage across the filament to null the bridge circuit. Output reading is 0 to 7VDC.
5.6 MICRO-ION GAUGE
The ion gauge measures pressures below 1x10-2 Torr. A micro-ion gauge will used during the ACS TB/TV
test to signal that the pressure in the ACS is low enough to operate the SBC HVPS and the instrument’s
calibration lamps. The SBC HVPS must not be operated until the ACS internal pressure is less than 2x10 -5
Torr in order to avoid the risk of corona discharge which may damage the SBC detector.
6.0 TEST TOLERANCES AND SPECIFICATIONS
Unless otherwise specified in the thermal test procedure, the following tolerances shall be used during the
TB/TV test:
Pressure/Vacuum
1.3x104 Pa (100 Torr)  5%
1.3x104 Pa to 1.3x102 Pa (100 Torr to 1 Torr)  10%
1.3x102 Pa to 1.3x101 Pa (1 Torr to 1 x10-3 Torr)  25%
Less than 1.3x101 Pa (<1x10-3 Torr)  80%
GSE Temperature
Shroud and GSE to 2 °C
Thermal Stability
Thermal Balance
ACS thermal balance temperature stabilization shall be considered established when the readings of all flight
and test temperature sensors vary by no more than 1.0°C for five hours with a decreasing slope with a fixed
electronics power profile and a stable environment. In addition, heater power shall not vary by more than 5%
over the last five hours. The TTC will use this stabilization criterion as a guide for declaring thermal
equilibrium, and shall determine when this temperature stabilization has occurred.
Thermal Vacuum
TV temperature stabilization shall be considered established when either of the MEB thermistors (JMEB1TMP
or JMEB2TMP) are within temperature tolerance (±3.0°C of the hot or cold prediction of table 5-1), and three
consecutive MEB readings taken 15 minutes apart are within 1.0°C with a decreasing slope. This stabilization
criterion will be used as a guide for achieving the TV temperature extremes. The TTC will have final authority
to determine when acceptance temperature stabilization has occurred.
7.0 CLEANLINESS AND CONTAMINATION MONITORS
Several contamination controls are required for the ACS test. A clean tent outside chamber 225 will maintain a
Class 10,000 environment. Particle fallout plates, NVR plates, visual inspections and TQCMs will be employed
to verify the cleanliness of the chamber and its environment. During the thermal vacuum testing, four TQCMs,
two optical witness mirrors, and a cold finger will be used to monitor outgassing contamination. The following
sections detail the CC requirements, verification methods, and purge requirements of the test.
7.1 CHAMBER AND CLEAN TENT VERIFICATION (AMBIENT)
The chamber 225 clean tent will be certified as a Class 10,000 environment prior to the start of the
GSE/Chamber Pre-test Outgassing Certification. Once the certification is complete, an NVR plate will be
deployed in the tent. This plate will be analyzed after a suspicious event or at the end of all testing. The
chamber will then be vacuumed and wiped with IPA to achieve VCHS +UV (as per JSC-SN-C0005).
When the chamber cleaning is complete, particle fallout plates will be deployed in the chamber. The floors
in the clean tent will be cleaned once every 2 days, or at the discretion of the CCE.
7.2 ACS PURGE
11
After ACS has been exposed to thermal vacuum for the last time, it requires a purge at all times until launch
with an allowable interruption not to exceed one hour in any 24 hour period. The instrument will be purged
through the SI purge cart using Grade B bottles of GN2, or house GN2, at a rate of 7-10 ft3/hr. All house
supplied GN2 will be sampled prior to use for ACS and will only be used if it complies with the Grade B
specifications. Additionally, a purge will be maintained prior to the final thermal vacuum, with a goal of
maintaining purge at all times. GSFC Code 540.1 will maintain the ACS purge throughout GSFC testing.
The purge will be terminated while personnel are working in the chamber. An O2 meter will be located at
the chamber at all times when it is at ambient pressure with the ACS installed.
7.3 GSE/CHAMBER PRE-TEST OUTGASSING CERTIFICATION
The pre-test outgassing certification measures the baseline outgassing environment of the thermal vacuum
test. The pre-test outgassing certification requires that all the equipment for the ACS thermal vacuum test be
installed in the chamber as it would be for the ACS test, and that the TQCMs be located as they will be for
the ACS thermal vacuum test. The following sections outline the pre-test outgassing certification set-up and
measurement criteria.
7.3.1
Pre-Test Outgassing Set-Up
All of the equipment required for the ACS thermal vacuum test, except the ACS itself, will be
loaded into the chamber for a pre-test certification. Four TQCMs are required for outgassing
measurements. Two TQCMs will be mounted on the back thermal balance fixture panel viewing
the electronics bay vent and the optics bay vent. One TQCM will be mounted on the front of the
thermal balance fixture viewing the ACS aperture without compromising the view between the
calibration unit and the instrument. The fourth TQCM will be placed in the chamber with an
overall view of the entire test set-up. A cold finger is required for the end of the test.
7.3.2
Outgassing Certification
The TBF and RAS/Cal temperatures will be maintained at bakeout levels until the three TQCMs
mounted to the thermal balance fixture measure 2Hz/hr/hr at –20C, averaged over8 consecutive
hours. The temperatures of the TBF and RAS/Cal will be lowered to 30C for measurement of the
background outgassing rate. The fourth TQCM overlooking the entire test set-up has no specific
requirement. An eight hour cold finger will be used at the end of the pre-test outgassing
certification. See Section 9.2 and Table 8-1, test sequence identifications 2-4, for the pre-test
certification procedure.
7.4 ACS TV TEST SET-UP
7.4.1
TB/TV Test Set-Up
The Advanced Camera will be loaded into the thermal balance fixture, and into the GALLOWS
fixture inside the SSDIF cleanroom. The RAS/Cal and ACS (in the TBF in GALLOWS) will be
double bagged for transport to Chamber 225. The ACS and TBF and the RAS/Cal will be loaded
onto the facility payload cart (which sits on an air-pad table) outside the Chamber 225 clean tent.
Once it is secure, the outer bags will be removed and the facility payload cart/air-pad table will be
immediately moved into the clean tent. Before the ACS is completely unbagged, the tent will be
allowed to settle for one hour, followed by an inspection of the tent, facility payload cart, air-pad
table and bagged ACS, and a cleaning performed if necessary. The ACS should remain bagged as
long as possible. After the required TV set-up activities, the ACS/TBF, RAS/Cal, facility payload
cart and chamber will be inspected and cleaned as necessary prior to rolling the facility payload
cart into the vacuum chamber.
Once the test set-up inside the chamber is complete, a final contamination inspection and cleaning
will be performed, particle fallout plates and optical witness mirrors will be deployed and the
TQCMs’ positions will be verified. The final CC inspection should occur just prior to closing the
door. If any last minute work is required, another CC inspection will be required. The air-pad
table must be moved away from the chamber to close the door and will break through the far end
of the clean tent. After the air-pad table is moved the tent will be allowed to settle for one hour
12
prior to closing door. This will minimize the amount of contamination stirred up by moving the
table and breaking through the clean tent from entering the chamber as the door swings closed.
7.4.2
Outgassing Measurements
The four TQCMs employed in the ACS thermal vacuum test must be operational at all times.
They shall be allowed to increase in frequency up to 10,000 Hz for a 10 MHz crystal, and 15,000
Hz for a 15 MHz crystal, and shall be able to maintain –20°C and –65°C. At the discretion of the
CCE, the TQCMs may exceed the above limits. Both the internal and external outgassing rates of
the ACS will be determined using the TQCM data from this test. To that end, a +30°C soak will
be performed at the end of the thermal vacuum testing with the shrouds at –75°C if required. See
Section 9.7 and Table 8-1, test sequence identification 20 for the detailed procedure. An eight
hour cold finger shall be activated after all testing is complete with the instrument kept warm in
order to determine the constituents of the outgassing material.
7.5 CHAMBER BREAKS
If for any reason a chamber break is required, all precautions shall be taken to avoid contamination. The
TD and the CCE will work out a plan for transition to ambient and for chamber break operations to
minimize the contamination risk to the instrument.
7.6 TEST COMPLETION
At the completion of thermal vacuum testing, the ACS must be protected from contamination during
transition to ambient and from contamination generated during GSE tear down. If the steps outlined in this
plan are followed for transition to ambient, there is minimal contamination risk to the ACS. Any deviation
from this plan must be approved by the CCE and the TD. When the chamber is back to ambient
temperature and pressure, the ACS purge will be initiated as soon as possible. The ACS shall also be rolled
out of the chamber as soon as possible. At least 6 tapelifts shall be taken on the ACS/TBF and then it shall
be double bagged. Once this is completed, TV test de-integration activities can continue without
threatening the cleanliness of the ACS. The particle fallout plates, optical witness mirrors, and the NVR
plate will be removed for analysis. The ACS will be closely inspected back in the SSDIF and cleaned
where necessary before further testing commences.
8.0 THERMAL TEST PLAN
8.1 GENERAL
The contamination sensitivity of the ACS and the HST require that a pre-test vacuum outgassing
certification be performed on the chamber and GSE prior to the start of the ACS TB/TV test. Testing of the
ACS instrument will encompass performing five (5) thermal balance cases, (2) thermal vacuum cycles, an
instrument calibration, and an outgassing certification. The thermal balance tests shall be performed first
and may include certain functional tests designed to characterize and determine detector baseline data. The
thermal vacuum test will then be performed with performance and functional testing planned at each
temperature plateau. The last phase of testing will be an instrument calibration using RAS/Cal and the
Backlight. If the outgassing requirement has not been met during the previous hot phases, the test will finish
with an extended soak at 30C until the outgassing requirement is complete. The detailed steps to complete
this profile are outlined in the Thermal Test Matrix, Table 8-1 and Section 9.
8.2 PRE-TEST CHAMBER/GSE OUTGASSING CERTIFICATION
This test will be performed with all the GSE for the ACS TB/TV test loaded into the chamber in its test
configuration. The thermal case simulates the worst outgassing potential throughout different stages of the
ACS testing. The temperature setpoints are shown in Table 8-1, ID # 2-4. Throughout the pre-test
certification and the ACS TB/TV testing, the RAS/Cal box and coronagraphic backlight will remain near
ambient temperatures.
8.3 THERMAL BALANCE
The first segment of the test is the thermal balance. During these portions of the thermal test program, the
ACS will be exposed to four different HST aft shroud orbital environments. The balances shall be
13
accomplished by holding the payload electrical power, chamber temperature and test heater power constant,
and allowing the ACS to achieve thermal stability as defined in Section 6. Immediately following the hot
operation thermal balance case, two of the internal cal lamps will be powered on to determine their effects
on temperatures. Finally, the MAMA detector will be powered “ON” in low voltage mode while the HRC
is powered “OFF” for another thermal balance case. These sensitivity studies will provide additional
temperature data for the thermal analyst to verify how this normal operational cycling of detector power and
change in internal dissipations correlates to thermal math model predictions.
All test and flight thermistors must meet the thermal stabilization requirement in order for thermal balance
to be declared. Thermal GSE component settings to be used during thermal balance testing are presented in
Tables 5-4 and 8-1.
8.3.1
Cold Safe Thermal Balance, TB#1
The first test to be performed is the Cold Safe TB. These test conditions will attempt to mimic the
worst cold HST aft shroud thermal environment that would occur during cold orbit safing of the
HST. In this case, the ACS will be in its safe power configuration with the TBF and chamber
shroud set to the cold safe temperatures listed in Tables 5-4 and 8-1. The ACS will then be
allowed to stabilize according to the criteria listed in Section 6.
8.3.2
Cold Operation Thermal Balance, TB#2
Following the Cold Safe TB stabilization, the TBF and chamber shroud will be set to their Cold
Operate temperatures according to the values listed in Tables 5-4 and 8-1 and the ACS will be
brought up to WFC and HRC operate mode. The environments and powers will then be held
constant while the ACS stabilizes to this TB point as defined in Section 6.
8.3.3
Cold Anneal Thermal Balance, TB#3
After Cold Operation TB stabilization is declared, the instrument will be reconfigured to its anneal
power profile and the thermal environments will be transitioned to the predicted Cold Anneal TB
case temperatures as listed in Tables 5-4 and 8-1. The ACS will then be allowed to stabilize
according to the criteria listed in Section 6.
8.3.4
Hot Operation Thermal Balance, TB#4
The next thermal balance point will simulate operation in the predicted worse case hot operate
environments. In this case, the TBF and chamber shroud will be set to their hot operate values as
listed in Tables 5-4 and 8-1 and the system will be allowed to stabilize according to the criteria
listed in Section 6.
Then HRC calibration platform D2 lamp and the WFC calibration platform Tungsten lamp will be
powered on and thermal trending data will be taken for one hour. After one hour maximum, the
D2 lamp will be powered off. Thermal trending will continue until directed by the TTC. Then the
Tungsten will be powered off.
8.3.5
MAMA On, HRC Off at Hot Operation, TB#5
A thermal stabilization of the ACS will be established in a WFC/SBC operate configuration
following Hot Operate TB using the same thermal environments as the preceding case, as shown in
Table 8-1. The ACS will be reconfigured from WFC/HRC operation to WFC/SBC operation and
thermal equilibrium will be established as defined in Section 6.
8.4 THERMAL VACUUM
This test will subject the ACS to two (2) temperature cycles between hot and cold temperature extremes
which are more severe than expected mission predictions.
The setpoints chosen for the chamber shrouds and TBF to establish TV soaks will, as a goal, subject
components to 10C beyond the worst mission on-orbit hot and cold operating scenarios. These initial
setpoints are provided in Tables 5-4 and 8-1, and were obtained from thermal analysis of the ACS, using
14
geometric and thermal math models and from correlation of the TMM from data acquired during the ACS
Thermal Vacuum Test #1 and the ACS/ASCS Compatibility Test (ACS TV Test #2.)
The thermal vacuum final soak temperature predictions are provided in Tables 5-1 and 5-3. It should be
noted that these soak temperatures may be less extreme than the qualification limits due to testing
limitations. Since these are predicted values, the TTC may (after reviewing the thermal data) determine that
less severe qualification limits are acceptable. The final soak temperatures achieved shall be determined by
the TTC after consultation with the TD and HST project.
The thermal vacuum soak stabilization criteria is presented in Section 6. When either of the MEB
thermistors is within 3C of its goal temperature, then the soak will be considered started.
During TV testing, functional tests shall begin after TV stabilization is achieved. The soak will end at the
conclusion of the functional tests and/or after 16 hours from the time the soak was achieved.
8.5 INSTRUMENT CALIBRATION
Instrument calibration will be performed using the RAS/Cal. The RAS/Cal source will be a HeNe LASER
outside the chamber which will be transmitted via a fiber optic cable through the chamber wall.
Additionally there will be a “backlight” which consists of a PtNe lamp reflected off of a piece of
Spectralon into the instrument. The instrument calibration tests are designed to address the following nine
items.
8.5.1
Basic Detector Properties
These properties are the gain, read-noise, and dark current for the CCDs and the dark noise for the
MAMA. For the CCDs, these properties will be determined at the lowest stable CCD temperature
under the hottest environmental temperatures and at the following predicted nominal CCD
temperature settings: WFC at -77C, HRC at -80C.
8.5.2
Charge Transfer Efficiency (CTE)
A full CTE versus exposure level curve will be made for each CCD at the nominal CCD
temperature. Both serial and parallel CTE will be measured. The CTE as a function of CCD
temperature will be monitored at five well chosen exposure levels.
8.5.3
Detector Features
The number and location of hot and unresponsive pixels and detector columns will be monitored as
a function of time and CCD temperature for the HRC and WFC.
8.5.4
Dark Structure
Long duration dark frames will be taken to determine if there is structure in the dark current, and to
provide more precise determination of the average dark current.
8.5.5
Image Stability
This test will determine whether thermal variations cause any mechanical stresses on the
instrument that may effect image quality. This will be done by deploying the coronagraph arm and
then monitoring the HRC images for changes in spot location while the instrument is cycled
through various environmental temperatures. The WFC will also be tested for stability using
RAS/Cal during thermal cycling.
8.5.6
Internal Calibration System Verification
This test will exercise all of the internal calibration lamps to verify operational capabilities, if
adequate exposures can be obtained, and to verify if the model count rate calculations are valid.
Of special concern is whether the filter in front of the SBC D2 lamp is optimal.
8.5.7
Flatfield Uniformity
This component will test how flat the flatfields are and how flatfield shape varies with wavelength.
High S/N flats will be obtained for all detectors.
15
8.5.8
Flatfield Stability
This component will test whether the flatfield shape varies with time and, in the case of the CCDs,
with the temperature of the CCD to determine, in particular, whether pinholes become a problem at
any CCD temperature.
8.5.9
SBC Flats
This component will provide SBC delta flats, totaling 10k e-/px using the external lamp with
filter F115LP and F165LP. It will also provide a set of short exposure internal D2 flats through
each of the
remaining SBC filters/prisms to estimate the count rates. In addition a set of 3600s SBC dark
exposures will be taken to characterize dark rate vs MAMA tube temperature (as the MAMA tube
warms up from nominal operation.)
8.6 OUTGASSING CERTIFICATION
This test will measure the outgassing rate of the optics cavity, the electronics cavity, and the outside of the
instrument. The ACS and TBF will be held at 30C and the shrouds will be at -75C to minimize input
from the chamber walls to the outgassing signal. Testing will continue until the TQCM monitoring the
optics cavity reads 13.5 Hz/Hr (15 MHz TQCM) at –65C and the other TQCMs mounted on the TBF
read 16 Hz/Hr (15 MHz TQCM) at –20C, averaged over 5 contiguous hours.
9.0 THERMAL TEST PROCEDURE
The test sequence outlined in this section shall be strictly followed. Any changes to the sequence must have
prior approval from the TD. The Thermal Test Matrix, Table 8-1, and the Thermal Test Equipment TB/TV
Temperature Settings, Table 5-4 are to be referred to for configuring the chamber shroud, TBF during the test.
Any deviation from these tables and/or procedures must be approved by the TTC. Deviations are to be recorded
in the logbook and redlined in the master thermal test procedure per instructions in Section 12.3. Thermal test
data will be collected according to the following procedures:
The TTCs shall obtain periodic snaps of the thermocouples from the Code 549 data acquisition system.
Eight hour plots of the thermocouple plot groups shall be made at the completion of each shift, at the discretion
of the TTC
Designated ACS flight telemetry pages shall be snapped or recorded every hour at the discretion of the TTC.
Monitor and record the designated test thermistor data.
The TTCs will log thermal and functional events in the designated test logbook.
9.1 INSTALLATION OF THE TEST EQUIPMENT INTO THE TV CHAMBER FOR THE PRE-TEST CERTIFICATION
9.1.1
Configure the TBF for Pre-Test Certification:
9.1.1.1
Install the TBF into the GALLOWS fixture per P-442-2406.
9.1.1.2
Install the C-channel rails and kinematic ball feet.
9.1.1.3
Bag the TBF using a double layer of Llumalloy.
16
9.1.1.4
Install the ACS Square TV Aluminum mounting plate and I-Beams onto the Chamber
Payload Table.
9.1.1.5
Locate the GALLOWS with TBF adjacent to the payload cart in preparation for
installation onto the 6’ x 12’ plate.
9.1.1.6
Install the RAS/Cal onto the 6’ x 12’ plate per P-442-2034, RAS/Cal Lifting and
Handling Procedure and position it approximately in the location required for ACS.
9.1.1.7
Install the TBF onto the 6’ x 12’ plate per Section TBD of P-442-2406, Procedure for
Use of ACS Gallows for Rotating the TBF.
9.1.1.8
Remove the outer bag of Llumalloy from RAS/Cal and then from the TBF.
9.1.1.9
Translate the payload cart into the Class 10,000 clean tent.
9.1.1.10 Unbag the TBF and RAS/Cal.
9.1.1.11 Install the backlight.
9.1.1.12 Translate the payload cart with the TBF and the RAS/CAL mounted on it, into Chamber
225.
9.1.1.13 Configure the chamber external electrical connections as shown in Figure 4-5 and Table
4-1.
9.1.1.14 Complete the chamber internal electrical connections as shown in Figure 4-4 and Table
4-1. The order of connections is as follows:
TBF
TQCMs
Coronagraph Diffuse Backlight.
RAS/CAL
9.1.1.15 Verify the function of RAS/Cal and that the Heaters and T/Cs are properly connected
and functioning (Optics Group.)
9.1.1.16 Verify the electrical connectivity and functionality of:
TBF
TQCMs
Choronograph Diffuse Backlight.
9.1.1.17 Check the routing and lengths of the internal chamber ACS instrument cables.
9.2 PRE-TEST GSE/CHAMBER OUTGASSING CERTIFICATION
17
The pre-test GSE/chamber outgassing certification detailed below is performed to verify that the equipment
used with the ACS during TB/TV testing does not contaminate the ACS. The certification also provides a
GSE/chamber outgassing background so that an accurate determination of the outgassing of the instrument
can be determined. The following sections provide the specific steps needed to achieve the required
outgassing measurements.
9.2.1
Outgassing Certification Case
9.2.1.1 Close the chamber door after the Code 549 and 545 final inspections and proceed to
vacuum.
9.2.1.2 When vacuum is achieved, transition the equipment to the following settings:



Heater circuits set as shown in Table 8-1, test sequence 2, Bakeout Phase I and II.
Scavenger plate flooded.
TQCMs set to 30C.
9.2.1.3 When all TQCMs measure less than 5Hz/Hr/Hr (averaged over 4 hours), transition the
TQCMs to -20C .
9.2.1.4 When all TQCMs measure less than 8Hz/Hr/Hr (averaged over 4 hours), transition the
heater circuits as shown in Table 8-1, test sequence 3, Bakeout Phase III.
9.2.1.5 When all TQCMs measure less than 5Hz/Hr/Hr (averaged over 4 hours), transition the
heater circuits as shown in Table 8-1, test sequence 4, Certification Phase.
9.2.1.6 When all TQCMs measure less than 2Hz/Hr/Hr (averaged over 8 hours) activate coldfinger and hold for 8 hours.
9.2.2 Return From Pre-Test Certification to Ambient
9.2.2.1 When the cold finger is complete, transition the TQCMs to 0C, and the heater circuits as
shown on Table 8-1, test sequence 5, Return to Ambient.
9.2.2.2 Once the chamber shroud is at ambient, transition the chamber to ambient pressure per
code 549 standard backfill procedures.
9.3 INSTALLATION OF ACS AND THE TEST EQUIPMENT INTO TV CHAMBER 225
9.3.1
9.3.2
Set up SITS
9.3.1.1
Move SITS to chamber 225.
9.3.1.2
Set up SITS in its configuration for the TV test.
9.3.1.3
Perform the Building 7 generator test.
Configure ACS for Test
In the GSFC Building 29 SSDIF, with ACS installed on the handling dolly, configure ACS for the
TB/TV test as follows:
18
9.3.3
9.3.2.1
Remove the vent covers
9.3.2.2
Remove the flight vents from the aft end of the instrument
9.3.2.3
Remove the astronaut handle
9.3.2.4
Install the Convectron and Micro-Ion gauge
9.3.2.5
Install the ASCS Double Saddle in flight configuration
9.3.2.6
Expose the instrument alignment cubes
9.3.2.7
Prior to moving the ACS to chamber 225, verify the following:
Verify that the aisle ways leading to Chamber 225 are clear.
Verify that the instrument ground cable is staged and verified outside the cleanroom for
transition to the TV chamber.
Verify that the 6’ x 12’ plate is assembled onto the Chamber 225 payload cart.
Verify that the payload cart is stationed outside the clean tent and is ready for ACS
installation.
Verify that the RAS/CAL is double bagged, stationed outside the clean tent, and ready
for installation onto the payload cart.
Verify the Class 10,000 clean tent is in place and certified.
Install ACS into the TBF
9.3.3.1
Execute the ACS EICIT per P-442-2609, ACS EICIT Procedure.
9.3.3.2
Install ACS into TBF per Section 4.1 of P-442-2118, Axial Science Instrument (ASI)
Installation & Removal To/From the Thermal Balance Fixture. Do not install the
outboard panels.
9.3.3.3
Install J1 –J4, the AUX2, the external thermistor cable and the ground cable.
9.3.3.4
Install the outboard panels.
9.3.3.5
Bag the TBF using a double layer of Llumalloy. The bagging shall allow for the
electrical harnesses and purge line connection to the ACS.
9.3.3.6
Install the TBF in GALLOWS in diamond per P-442-2406.
9.3.3.7
Install the C-channel and kinematic feet.
9.3.3.8
Disconnect the facility nitrogen purge from the purge cart. Disconnect the purge cart
line from ACS. Record the time: ___________
9.3.3.9
Translate to and position the purge cart at Chamber 225. Connect the purge cart to the
facility nitrogen source.
19
9.3.3.10 Translate the TBF/ACS to the GSFC Building 7 Chamber 225. Ensure that the TBF is
grounded at all times during the move.
9.3.3.11 Locate the GALLOWS/TBF/ACS adjacent to the payload cart in preparation for
installation onto the 6’ x 12’ plate.
9.3.3.12 Rotate the TBF in GALLOWS into SQUARE. Install the TBF/ACS onto the 6’ x 12’
plate per Section of P-4429.3.3.13 Remove the outer layer of Llumalloy bagging from RAS/CAL and then the TBF/ACS.
9.3.3.14 Translate the payload cart into the Class 10,000 clean tent.
9.3.3.15 Connect the purge cart to the facility nitrogen source, verify flow, let the gas flow for 10
minutes and then connect it to the ACS.
Record the time: ______________
Note: The purge should remain connected to ACS except when personnel are working
in the chamber. When personnel are not working in the chamber (i.e. overnight), tape
the purge line to the aperture snorkel of the ACS.
9.3.3.16 Allow the tent interior to settle for 1 hour. After an hour, inspect the tent, the payload
cart, the table, the RAS/CAL, and the TBF/ACS and perform cleaning as necessary.
9.3.3.17 Remove the inner bag from the TBF/ACS and the RAS/CAL.
9.3.3.18 Hook up A/C unit duct to saddle inlet.
9.3.3.19 Level ACS to gravity and align the RAS/CAL to the TBF/ACS.
9.3.3.20 Translate the payload cart, with the TBF/ACS and the RAS/CAL mounted on it, into
Chamber 225 about half-way.
9.3.3.21 Configure the chamber external electrical connections as shown in Figure 4-5 and Table
T-1.
WARNING! Danger of Asphyxiation. Prior to entering the TV chamber, stop the
nitrogen purge. Use an oxygen monitor to verify that the percentage of oxygen in the
chamber is greater than 19.5%.
9.3.3.22 Complete the chamber internal electrical connections as shown in Figure 4-4 and Table
T-1. The order of connection is as follows:
Instrument Internal Convectron and Micro-Ion gauge
Test Ground
ACS
TBF
TQCMs
RAS/CAL
Backlight
ATTITUDE
20
WARNING! Danger of Asphyxiation. Prior to entering the TV chamber, stop the
nitrogen purge. Use an oxygen monitor to verify that the percentage of oxygen in the
chamber is greater than 19.5%.
Verify that the temperature sensors are electrically connected and are being read into the
correct mnemonic in the data collection system. The flight data will be verified at
section 9.4.
9.3.3.23 Perform the operational checkout of the RAS/CAL.
9.3.3.24 Verify the electrical connectivity and functionality of:
TBF
ACS Convectron and Micro-ion Gauge
TQCMs
Diffuse light source
9.4 THERMAL BALANCE
9.4.1
9.4.2
Ambient
9.4.1.1
Turn “On” and initialize SITS to support instrument operations as per Section 2, “SITS
Set-Up” of the “ACS Basic Operations Overview”, P-442-1526. (Verify flight safing
sequences are loaded.)
9.4.1.2
Perform the ACS Abbreviated Functional Test procedures in accordance with P-4422616.
9.4.1.3
Transition the instrument to “WFC/HRC Operate State” as per Section 3.1.1, “Off to
Operate”, of P-442-1526, the “ACS Basic Operations Overview”.
9.4.1.4
Level the ACS in the TBF. Align the RAS/CAL to the TBF.
9.4.1.5
Configure the WFC and HRC detector as per FTC instruction using Section 4.1 of the
“ACS Basic Operations Overview” P-442-1526. Capture the WFC-RAS/Cal align and
HRC-Backlight align data as per FTC instruction using Section 4.2 of the “ACS Basic
Operations Overview”..
9.4.1.6
Verify ACS HP’s are level by watching the Radiator Temp. JO2FPANT and the I/F
plate Temp. JINTFCT.
9.4.1.7
Transition the instrument to its “Off State” as per Section 3.3.1, “Quick Power Down”,
of the “ACS Basic Operations Overview,” P-442-1526.
Vacuum Acquisition
9.4.2.1
Close the chamber door. Make sure nothing inside the chamber is powered on, except
the chamber convectron gage. Instruct the TD to configure the ACS for pumpdown.
When completed, start pump down of the chamber.
9.4.2.2
When the chamber pressure reaches 1x10-5 Torr, verify or set all TBF heater circuits to
+22C. Transition the shrouds to –55°C and activate the TQCM. Hold this
configuration for 24 hours.
21
9.4.2.3
Record the chamber pressure:
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn on the ACS internal convectron and take a pressure reading. If the pressure is
below 1x10-2 Torr, turn on the ion gauge and take a pressure reading.
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn off the ACS internal convectron and the ion gauge.
9.4.3
Cold Safe - Thermal Balance #1
9.4.3.1
Perform Aliveness Test Side 1 and 2 per P-442-2614, ACS Aliveness. Leave the ACS
instrument in SAFE mode at the end of the Aliveness test.
9.4.3.2
Record the chamber pressure:
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn on the ACS internal convectron and take a pressure reading. If the pressure is
below 1x10-2 Torr, turn on the ion gauge and take a pressure reading.
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn off the ACS internal convectron and the ion gauge.
9.4.4
9.4.3.3
Set the controls for the chamber, and TBF heater circuits for transition to the settings for
test sequence 8 of Table 8-1, Cold Safe Thermal Balance TB#1.
9.4.3.4
Closely monitor and allow the payload temperatures to stabilize to the criteria specified
in Section 6, Test Tolerances. All test and flight thermistors shall be used to determine
temperature stability.
9.4.3.5
When the ACS temperatures meet the stability requirements of Section 6, as determined
by the TTC, the cold safe thermal balance is completed. Record event in logbook
including all final power and temperature readings. Note that all of the ACS
temperatures can not be read until the ACS is brought back up to operate in Section
9.4.3.6.
9.4.3.6
Transition the instrument to Operate mode by executing steps 3 through 5 of Section
3.1.1, “Off to Operate”, of P-442-1526, the “ACS Basic Operations Overview”. Use the
option for NOT powering the TECs. Snap the “Temps” page from the CCS telemetry.
9.4.3.7
Transition the instrument back to SAFE mode by executing steps 1 of Section 3.3.1, of
P-442-1526, the “ACS Basic Operations Overview”.
Cold Operation - Thermal Balance #2
9.4.4.1
Record the chamber pressure:
22
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn on the ACS internal convectron and take a pressure reading. If the pressure is
below 1x10-2 Torr, turn on the ion gauge and take a pressure reading.
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn off the ACS internal convectron and the ion gauge.
9.4.4.2
Set the controls for the TBF heater circuits for transition to the settings in Table 8-1, test
sequence 9, Transition to Cold Operate, TB#2.
9.4.4.3
Transition the instrument to Operate mode by executing steps 3 through 5 of Section
3.1.1, “Off to Operate”, of P-442-1526, the “ACS Basic Operations Overview”. Use the
option for powering the TECs. Set the WFC at –77C and HRC at -80C.
9.4.4.4
Perform data extraction on detector power and temperatures, I/F temperature, Heat Pipe
temperatures, and window temperatures. Wait until TTC has gathered all necessary data
in Operate Mode. Snap the “Temps” page from the CCS telemetry.
9.4.4.5
Closely monitor and allow the payload temperatures to stabilize to the thermal balance
criteria in Section 6. All test and flight thermistors shall be used to determine
temperature stability.
9.4.4.6
When the ACS temperatures meet the stability requirements of Section 6, as determined
by the TTC, the Cold Operate thermal balance is completed. Record event in logbook
including all final power and temperature readings. Snap the “Temps” page from the
CCS telemetry.
9.4.4.7
Verify the fix for the thermistor and heater zone, HAR 1342.
9.4.4.8
Set the CCD TECs to their coldest stable temperatures using the following procedure.
The HRC CCD setpoint is selected using Section 4.1.1, “CCD TECs” of P-442-1526,
the “ACS Basic Operations Overview”. The WFC CCD setpoint is selected using
Section 5.1.1 of the “ACS Basic Operations Overview”.
For each of the setpoints in the following tables, issue the setpoint command, allow the
temperatures to stabilize, and record the indicated telemetry readings from page JTEC.
When/if the minimum temperature setting is passed, immediately set the setpoint to
- 80.0°C for the HRC and - 77.0°C for the WFC and allow the system to stabilize. The
minimum temperature has been passed when any of the following conditions occur:
1.
2.
3.
4.
Housing temperature 33.0C or is continuously rising.
Detector Temp does not move toward the setpoint after five readings.
Detector Temp increases across three consecutive readings.
Detector Temp reaches the setpoint but current doesn’t decrease below 4 Amps after
five minutes.
23
WFC
Set Point
-77.0
-80.0
-83.0
-85.0
-87.0
-89.0
-90.0
-91.0
-92.0
-92.35
JWTECI1
(TEC current)
JWHOUSET
(Housing Temp)
JWDETMP1
(Detector Temp)
JWTECTCT
(Set Point)
HRC
Set Point
-80.0
-83.0
-85.0
-87.0
-89.0
-90.0
-91.0
-92.0
-92.35
JHTECI1
(TEC current)
JHHOUSET
(Housing Temp)
JHDETMP1
(Detector Temp)
JHTECTCT
(Set Point)
9.4.5
Cold Anneal - Thermal Balance #3
9.4.5.1
Record the chamber pressure:
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn on the ACS internal convectron and take a pressure reading. If the pressure is
below 1x10-2 Torr, turn on the ion gauge and take a pressure reading.
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn off the ACS internal convectron and the ion gauge.
9.4.5.2
Set the controls for the TBF heater circuits for transition to the settings in Table 8-1, test
sequence 10 , Transition to Cold Anneal, TB#3.
9.4.5.3
Configure the instrument to the ANNEAL operational state using STScI commanding,
JTVANNEAL SMS.
9.4.5.4
Closely monitor and allow the payload temperatures to stabilize to the thermal balance
criteria in Section 6. All test and all available flight thermistors shall be used to
determine temperature stability.
24
9.4.6
9.4.5.5
When the ACS temperatures meet the stability requirements of Section 6, as determined
by the TTC, the Cold Anneal thermal balance is completed. Record event in logbook
including all final power and temperature readings. Note that all of the ACS
temperatures can not be read until the ACS is brought back up to operate in Section
9.4.5.8.
9.4.5.6
Verify calibration curve for interface plate thermistor, HAR number 1560 (by looking at
temperatures during anneal).
9.4.5.7
Transition the instrument to WFC/HRC Operate mode, without the TECs on, and
perform data extraction on detector power and temperatures, I/F heater power and
temperature, Heat Pipe temperatures, and window heater power and temperatures. Wait
until TTC has gathered all necessary data in Operate Mode. Snap the “Temps” page
from the CCS telemetry (~ 1 minute.)
9.4.5.8
Transition to Anneal with R/T commanding.
9.4.5.9
Transition the instrument from Anneal to operate using STScI commanding, the
JTVANNEAL SMS.
Hot Operation - Thermal Balance #4
9.4.6.1
Verify that RAS/Cal and the Backlight are powered on.
9.4.6.2
Deploy the coronagraphic spot arm as per Section 9.7 of P-442-1526, the “ACS Basic
Operations Overview” and move filter wheel so that F625W is in front of WFC.
9.4.6.3
Inform the Science Team that image stability data collection is about to start.
9.4.6.4
Commence image stability data collection per TBD
9.4.6.5
Proceed to transition when directed by the Science Team.
9.4.6.6
Set the controls for the chamber shrouds, and TBF heater circuits for transition to the
settings in Table 8-1; test sequence 11, Transition to Hot Operations, TB#4.
9.4.6.7
Closely monitor and allow the payload temperatures to stabilize to the thermal balance
criteria in Section 6. All test and flight thermistors shall be used to determine
temperature stability.
9.4.6.8
When the ACS temperatures meet the stability requirements of Section 6, as determined
by the TTC, the Hot Operate thermal balance is completed. Record event in logbook
including all final power and temperature readings.
9.4.6.9
Discontinue image stability data.
9.4.6.10 Power off the RAS/Cal and Backlight.
9.4.6.11 Set the CCD TECs to their coldest stable temperatures using the following procedure.
25
The HRC CCD setpoint is selected using Section 4.1.1, “CCD TECs” of P-442-1526,
the “ACS Basic Operations Overview”. The WFC CCD setpoint is selected using
Section 5.1.1 of the “ACS Basic Operations Overview”.
For each of the setpoints in the following tables, issue the setpoint command, allow the
temperatures to stabilize, and record the indicated telemetry readings from page JTEC.
When/if the minimum temperature setting is passed for HRC, immediately set the
setpoint to - 80.0°C for the HRC and commence walking the WFC down. When the
minimum temperature setting is passed, leave WFC at its minimum. This become the
WFC nominal setpoint. The minimum temperature has been passed when any of the
following conditions occur:
5.
6.
7.
8.
Housing temperature 33.0C or is continuously rising.
Detector Temp does not move toward the setpoint after five readings.
Detector Temp increases across three consecutive readings.
Detector Temp reaches the setpoint but current doesn’t decrease below 4 Amps after
five minutes.
HRC
Set Point
-80.0
-83.0
-85.0
-87.0
-89.0
-90.0
-91.0
-92.0
-92.35
JHTECI1
(TEC current)
JHHOUSET
(Housing Temp)
JHDETMP1
(Detector Temp)
JHTECTCT
(Set Point)
WFC
Set Point
-77.0
JWTECI1
(TEC current)
JWHOUSET
(Housing Temp)
JWDETMP1
(Detector Temp)
JWTECTCT
(Set Point)
-80.0
-83.0
-85.0
-87.0
26
-89.0
-90.0
-91.0
-92.0
-92.35
9.4.6.12 Deploy the cal door.
9.4.6.13 Power on the D2 lamp on the HRC cal platform and one Tungsten lamp on the WFC cal
platform. Record time below:
Lamps On:
Date__________ Time_____________
9.4.6.14 When directed by the TTC and/or after 1 hour maximum, power off the D2 lamp. When
directed by the TTC power off the Tungsten lamp.
9.4.7
D2 Lamp Off:
Date__________ Time_____________
Tungsten Lamp Off:
Date__________ Time_____________
MAMA “On” Sensitivity at Hot Operation Thermal Balance
9.4.7.1
Record the chamber pressure:
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn on the ACS internal convectron and take a pressure reading. If the pressure is
below 1x10-2 Torr, turn on the ion gauge and take a pressure reading.
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn off the ACS internal convectron and the ion gauge.
9.4.7.2
Transition to “WFC/SBC Operate” state as per Section 3.2.1., “WFC/HRC Operate to
WFC/SBC Operate”, of P-442-1526, the “ACS Basic Operations Overview”. Do not
turn on the MAMA HVPS unless the internal ACS pressure is  2x10-5 Torr. If the
pressure is  2x10-5 Torr, inform the science team that SBC darks will commence
shortly.
27
Caution: The MAMA tube temperature (JMTUBET on page JHLDTMP) must not
exceed 45C during this transition. If it approaches this temperature, reduce the SSM
sinks by 5C before the tube reaches 45C.
9.4.7.3
If the pressure is  2x10-5 Torr, obtain a set of SBC dark exposures to characterize dark
rate vs. MAMA tube temperature using R/T commanding.
9.4.7.4
Closely monitor and allow the payload temperatures to re-stabilize to the thermal
balance criteria in Section 6. All test and flight thermistors shall be used to determine
temperature stability.
9.4.7.5
When the ACS temperatures meet the stability requirements of Section 6, as determined
by the TTC, the MAMA “ON” sensitivity at Hot Operate thermal balance is completed.
Record event in logbook including all final power and temperature readings. Snap the
“Temps” page from the CCS telemetry.
9.5 THERMAL VACUUM
9.5.1
9.5.2
9.5.3
Transition to Hot Soak #1
9.5.1.1
Transition to the from the WFC/SBC to the WFC/HRC Operate State as per Section
TBD, of P-442-1526, the “ACS Basic Operations Overview”.
9.5.1.2
Set the controls for the chamber shrouds and TBF heater circuits for the transition to the
settings in Table 8-1; test sequence 12, Hot Soak #1.
9.5.1.3
When both of the MEB thermistors have met the stabilization criteria of section 6,
proceed with Hot Soak #1.
Hot Soak #1
9.5.2.1
Perform the Mech. Relay Test (P-442-2482). Leave ACS in WFC/HRC Operate mode at
the end of the Mech. Relay Test(skip section 4.4).
9.5.2.2
Hold at Hot Soak for 16 hours from 9.4.6.8 and transition when directed by the TTC.
Transition to Cold Soak #1
9.5.3.1
Transition the instrument to SAFE mode as per step 1 of Section 3.3.1, “Quick Power
Down”, of P-442-1526, the “ACS Basic Operations Overview”.
9.5.3.2
Set the controls for the chamber shrouds and TBF heater circuits for the transition to the
settings in Table 8-1; test sequence 13, Transition to Cold Soak #1.
9.5.3.3
When either of the MEB thermistors have come within their cold stabilization
temperatures (3C), reset the TBF heater circuits to the cold soak temperatures listed in
Table 8-1, test sequence 14, Cold Soak #1.
9.5.3.4
After 1 hour at stability, transition the instrument to OFF mode as per Section 3.3.1,
“Quick Power Down”, of P-442-1526, the “ACS Basic Operations Overview”.
28
9.5.3.5
9.5.4
9.5.5
After 1 hour with ACS off, proceed with the Cold Soak Section.
Cold Soak #1 (with cold start side 1.)
9.5.4.1
Transition to the “WFC/HRC Operate State” as per Section 3.1.1, “Off to Operate”, of
P-442-1526, the “ACS Basic Operations Overview”. CCD’s nominal setpoints,
determined from section 9.4.6.11. (This is cold start #1.)
9.5.4.2
Perform the Mech. Relay Test (P-442-2482). Leave ACS in WFC/HRC Operate mode at
the end of the Mech. Relay Test(skip section 4.4) with TECs at the nominal setpoints
determined in section 9.4.6.11.
9.5.4.3
Perform CCD basic performance SMS’s.
9.5.4.4
Hold at Cold Soak until 16 hours has elapsed from 9.5.3.4 and transition when directed
by the TTC.
Transition to Hot Soak #2, Functional Test
9.5.5.1
Verify that RAS/Cal and the Backlight are powered on.
9.5.5.2
Deploy the coronagraphic spot arm as per Section 9.7 of P-442-1526, the “ACS Basic
Operations Overview” and move filter wheel so that F625W is in front of WFC.
9.5.5.3
Inform the Science Team that image stability data collection is about to start.
9.5.5.4
Commence image stability data collection per TBD
9.5.5.5
Proceed to transition when directed by the Science Team.
9.5.5.6
Set the controls for the chamber shrouds and TBF heater circuits for the transition to the
settings in Table 8-1; test sequence 15, Transition to Hot Soak #2.
9.5.5.7
When either of the MEB thermistors have come within their hot stabilization
temperatures (3C), reset the TBF heater circuits to the hot soak temperatures listed in
Table 8-1, test sequence 16, Hot Soak #2, Functional Test.
9.5.5.8
Discontinue image stability data.
9.5.5.9
Power off the RAS/Cal and Backlight.
9.5.5.10 Retract the coronagraphic arm as per Section 9.7 of P-442-1526, the “ACS Basic
Operations Overview”.
9.5.6
Hot Soak #2, Functional Test
9.5.6.1
When the ACS temperatures meet the TV stability requirements of Section 6, as
determined by the TTC, set input voltage at ACS to 21 volts, dwell for one (1) minute.
29
NOTE: Instrument may SAFE.
Record ACS and PDU input voltages:
Minimum Survival Voltage
At PDU
At ACS
9.5.6.2
Set input voltage to 28 volts at ACS. Verify nominal operation in operate for two (2)
minutes.
9.5.6.3
Set input voltage at ACS to 35 volts, dwell for one (1) minute.
Record ACS and PDU input voltages:
Maximum Survival Voltage
At PDU
At ACS
9.5.6.4
Set input voltage to 28 volts at ACS. Verify nominal operation in operate for two (2)
minutes.
9.5.6.5
Transition to SAFE.
9.5.6.6
Record the chamber pressure:
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn on the ACS internal convectron and take a pressure reading. If the pressure is
below 1x10-2 Torr, turn on the ion gauge and take a pressure reading.
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn off the ACS internal convectron and the ion gauge.
9.5.6.7
Perform ACS Functional Test procedures in accordance with P-442-2613 , “ACS
System Functional Test Side 1” for Side 1. Note: Do NOT execute Section 4.2.16,
“ACS Operations Tests – AMBIENT.” Do NOT turn on the MAMA HVPS unless the
internal ACS pressure is  2x10-5 Torr. End test in SAFE.
9.5.6.8
Record the chamber pressure:
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn on the ACS internal convectron and take a pressure reading. If the pressure is
below 1x10-2 Torr, turn on the ion gauge and take a pressure reading.
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
30
Turn off the ACS internal convectron and the ion gauge.
9.5.6.9
Perform P-442-2617 , “ACS System Functional Test Side 2” for side 2. Note: Do NOT
execute Section 4.2.16, “ACS Operations Tests – AMBIENT. Do NOT turn on the
MAMA HVPS unless the internal ACS pressure is  2x10-5 Torr. End test in Operate
Mode.
9.5.6.10 Set input voltage at ACS to 21 volts, dwell for one (1) minute.
NOTE: Instrument may SAFE.
Record ACS and PDU input voltages:
Minimum Survival Voltage
At PDU
At ACS
9.5.6.11 Set input voltage to 28 volts at ACS. Verify nominal operation in operate for two (2)
minutes.
9.5.6.12 Set input voltage at ACS to 35 volts, dwell for one (1) minute.
Record ACS and PDU input voltages:
Maximum Survival Voltage
At PDU
At ACS
9.5.6.13 Set input voltage to 28 volts at ACS. Verify nominal operation in operate for two (2)
minutes.
9.5.6.14 Verify 16 hours has elapsed since 9.5.6.1.
9.5.7
Transition to Cold Soak #2, Functional Test
9.5.7.1
Transition the instrument to SAFE mode as per step 1 of Section 3.3.1, “Quick Power
Down”, of P-442-1526, the “ACS Basic Operations Overview”. (TECs off.)
9.5.7.2
Set the controls for the chamber shrouds and TBF heater circuits for the transition to the
settings in Table 8-1; test sequence 17, Transition to Cold Soak #2.
9.5.7.3
When either of the MEB thermistors have come within their cold acceptance test
temperatures (3C), reset the TBF heater circuits to the cold soak temperatures listed in
Table 8-1, test sequence 18, Cold Soak #2, Functional Test.
9.5.7.4
After 1 hour at stability, transition the instrument to OFF mode as per Section 3.3.1,
“Quick Power Down”, of P-442-1526, the “ACS Basic Operations Overview”.
31
9.5.7.5
9.5.8
9.5.9
9.5.10
After 1 hour with ACS off, proceed with the Cold Soak, Functional Test Section.
Cold Soak #2, Functional Test (with cold start side 2)
9.5.8.1
Set the ACS input voltage to 24 volts.
9.5.8.2
After 1 hour, perform the ACS Functional Test procedures in accordance with P-4422617, “ACS System Functional Test Side 2” for Side 2. Note: Do NOT execute Section
4.2.16, “ACS Operations Tests – AMBIENT.” End in SAFE.
9.5.8.3
Perform P-442-2613, “ACS System Functional Test Side 1” for side 1. Note: Do NOT
execute Section 4.2.16, “ACS Operations Tests – AMBIENT.”
9.5.8.4
Transition to the “WFC/HRC Operate” state as per Section 3.1.1, “Off to Operate”, of P442-1526, the “ACS Basic Operations Overview”.
9.5.8.5
After 16 hours from section 9.5.8.1 and when directed by the FTC, proceed with the
calibration section.
Transition to Calibration
9.5.9.1
Set the ACS input voltage to 28 volts.
9.5.9.2
Set the controls for the chamber shrouds and TBF heater circuits for the transition to the
settings in Table 8-1; test sequence 19, Transition to Calibration.
Calibration
9.5.10.1 Record the chamber pressure:
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn on the ACS internal convectron and take a pressure reading. If the pressure is
below 1x10-2 Torr, turn on the ion gauge and take a pressure reading.
Record the convectron/ion gauge pressure reading: ______________ Torr
Record the date and time: ______________ EST
Turn off the ACS internal convectron and the ion gauge.
9.5.10.2 Obtain WFC and HRC basic CCD performance images, including bias and dark frames
and internal flats at all supported gain settings. (SMS JTVH01*, JTVW01*) [9 h]
9.5.10.3 Obtain SBC delta flats, totaling 10k e- per 4 px resolution element, through filter
F125LP using the internal D2 lamp. Use SBC “safe-open” procedure for initial
exposure, to assure safe MAMA tube illumination level. (R/T) [2 h]
9.5.10.4 Obtain a set of short exposure internal D2 flats through each of the remaining SBC
filters/prisms to estimate count rates. (R/T) [2 h]
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9.5.10.5 Obtain a set of 3600s dark exposures to characterize dark rate vs. MAMA tube
temperature. (R/T) [6 h]
9.5.10.6 Obtain high signal-to-noise ratio flats, totaling 10k e-/px, with the external “backlight”
source through filters F125LP and F165LP. Also obtain a flat for F122M if the count
rate achieved is adequate. Use the SBC “safe-open” procedure for initial exposure, to
assure safe MAMA tube illumination level. (R/T) [30 h]
9.5.10.7 Obtain WFC and HRC images, using EPER and FPR techniques and internal tungsten
lamps, at a variety of signal levels from 100 to 45k e-, to evaluate both parallel and serial
CTE at nominal operating temperature. (SMS JTVH05*, JTVW05*) [17 h]
9.5.10.8 Power off RAS/Cal and Backlight sources.
9.5.11
Transition to the Outgassing Certification
9.5.11.1 Transition heater circuits as per Table 8-1, test sequence 20, Transition to Outgassing
Verification.
9.5.11.2 Set all TQCM temperatures to -20C
9.5.12
Outgassing Certification
9.5.12.1 Hold until all TQCMs measure less than 16 Hz/Hr (averaged over 8 hours). Record the
temperature and outgassing rate for each TQCM
TQCM 1:
TQCM 2:
TQCM 3:
TQCM 4:
Temp.
Temp.
Temp.
Temp.
__________
__________
__________
__________
Rate:
Rate:
Rate:
Rate:
__________
__________
__________
__________
9.5.12.2 Transition the TQCM viewing the optical cavity vent to -65C
9.5.12.3 Hold for 4 hours. Record the temperature and outgassing rate for each TQCM
TQCM 1:
TQCM 2:
TQCM 3:
TQCM 4:
Temp.
Temp.
Temp.
Temp.
__________
__________
__________
__________
Rate:
Rate:
Rate:
Rate:
__________
__________
__________
__________
9.5.12.4 9.5.16 Activate cold-finger and hold for 8 hours.
9.6 TRANSITION TO AMBIENT TEMPERATURE
9.6.1.1
Set the controls for the chamber shrouds, and heater circuits for the transition to the
settings in Table 8-1; test sequence 21, Transition to Ambient Temperatures.
9.6.1.2
Transition the TQCMs to ambient temperatures.
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9.6.1.3
Verify ACS is powered off
9.6.1.4
Verify Backlight and RAS/Cal sources are powered off.
9.7 CHAMBER BACKFILL, AMBIENT ABBREVIATED FUNCTIONAL TEST
9.7.1.1
When the Chamber shroud is about 18C, power off all heater circuits to the RAS/Cal,
Backlight and TBF.
9.7.1.2
Verify ALL items in the chamber are powered off.
9.7.1.3
Backfill to ambient pressure per code 549 standard procedures.
9.7.1.4
Perform the ACS System Functional Test procedures in accordance with P-442-1512,
“ACS Functional Test – Side 1”, for side 1 and P-442-1528, “ACS Functional Test –
Side 2”, for side 2. Note do NOT execute Section 4.2.17, “ACS Operations TestsThermal Vacuum”.
9.8 TEST END
10.0 EMERGENCY CONDITIONS
The test conductors shall assess the test set-up and continuing performance from a safety aspect to assure that
safety concerns are being considered during all phases of the operations.
10.1 OPERATIONAL HAZARD ANALYSIS (OHA)
Various emergency conditions that have a reasonable possibility of occurring shall be noted in both the
chamber and ACS functional test procedures. The steps to be followed if those conditions occur shall also
be identified. An OHA document shall be prepared for the ACS TB/TV test. This document will help to
identify any unsafe conditions or possible emergencies that could develop during the test. Any necessary
responses to these documents shall be included in the test procedure developed by Code 549.
10.2 EMERGENCY PROCEDURES
Test article functional procedures and facility procedures shall be developed, implemented, and released
prior to the start of the test by the TVTE and FTC detailing action necessary in the event of the following
emergency conditions:
Building evacuation
Power Outage:
Chamber and Cryopanel temperature control
Loss of instrumentation and data acquisition system
Emergency Power changeover
Loss of vacuum, outboard leak of GN2 from TCU circuit or shrouds
Ammonia leaks
This emergency procedure is contained in Document 7544-TBD-98 ACS TV/TB Test Procedure.
In addition, the malfunctioning of equipment identified as critical shall warrant stopping the test and
performing repairs. The following equipment is identified as critical to supporting a successful test:
Chamber shroud temperature control
Vacuum system failure, which causes chamber pressure to exceed Tolerances in Section 6.
Cryopanel / thermal conditioning unit control
Data acquisition system
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Power control
Instrumentation
11.0 MEETINGS
11.1 SES CONFIGURATION BUY-OFF
Any test team personnel having configuration requirements for this test, shall visually inspect the payload
and test set-up for handling, safety, and accuracy to verify that configuration requirements have been met.
Any discrepancies shall be identified at this meeting and must be resolved prior to test start. Testing shall
begin only after the thermal, functional and facility chamber test procedures have been signed off.
11.2 TEST COORDINATION MEETING
During both the test set-up and performance of the test, brief daily meetings shall be conducted by the Test
Director to ascertain and disseminate what activities have been accomplished during the previous 24 hours.
In addition, this meeting is a venue for discussions of any problems/anomalies that have occurred and the
opportunity to direct the activity for the next 24-hour period.
11.3 TEST READINESS REVIEW
A complete Test Readiness Review will occur 72 hours prior to chamber pumpdown. All test team
personnel are required to attend.
12.0 GENERAL
12.1 TEST FAILURE AND ANOMALY REPORTING
Any failure noted during the performance of this procedure shall be documented in accordance with HARS.
All non-conformances or suspected non-conformances noted during the performance of this procedure shall
be documented immediately on a GSFC problem record on the back of the work order as specified by P442-0770. Quality shall verify that all problem reports are dispositioned at the completion of the work
order. All problem reports that are open at the completion of the work order shall be documented on an
HST Anomaly Report. Failure to meet ICD requirements will lead to the submission of new waiver
requests.
12.2 CONSTRAINTS
The following constraints are to be observed:
All cables (excluding RF cables) and plumbing shall be wrapped with MLI for a distance of 6 to 8 feet from
their ACS interface.
The temperature rate of change of the ACS electronic components shall be less than 20C/hr.
12.3 TEST PROCEDURE CHANGES
Changes to this procedure shall be incorporated by deviations and recorded on a deviation sheet marked
P#____ for permanent and T#____ for temporary and approved by the Test Conductor, Quality, and the
ASI representative. Changes within a hazardous portion of this procedure must also be approved by Safety.
The procedure shall be redlined with the appropriate deviation number next to the redlined portion. All
permanent deviations shall be incorporated into this procedure.
12.4 TEST SUCCESS CRITERIA
12.4.1
Verification of Thermal Design
Since the hot and cold TB cases represent the worst case flight orbits, the thermal design
verification shall be considered achieved if test temperatures are found to occur within the span of
acceptance temperature limits during the TB test. If test temperatures fall outside the span,
verification shall not be considered to have been achieved until further analysis can satisfactorily
explain the difference.
12.4.2
Verification of Thermal Analysis
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If the TB test temperatures for the ACS agree to within 5C of the predictions, correlation shall be
considered to have been achieved. If differences of greater than 5C exist, then additional
correlation of the TMM is required.
12.4.3
Verification of Electrical Performance
The ACS shall operate as designed throughout the test and a comparison of the pre- and post-test
functional tests shall show no degradation for the ACS electrical performance to be judged as
satisfactorily verified.
12.4.4
Verification of Flight Heaters
Both temperature and current indications shall be used to verify that all flight heaters are operating
as designed. If this is not shown, then those heaters not verified must be investigated after the test.
12.4.5
Verification of Calibration
The ACS internal calibration system shall operate as designed during the test and the SBC UV
throughput and flatfielding calibrations shall be successfully completed. Additionally, the HRC
CCD performance and the HRC and SBC image stability requirements over a temperature range
shall be demonstrated.
12.4.6
Verification of Outgassing Requirements
The four TQCMs employed during this test shall verify that the ACS internal outgassing properties
meet the HST outgassing rate requirements. ACS UV throughput shall be measured before and
after the TB/TV test to verify that the throughput was not degraded during testing.
13.0 SAFETY
The operations contained herein shall be monitored by the designated or cognizant HST Project Safety Engineer
as required by the authorizing work order. All required personnel shall become familiar with this procedure and
its precautions prior to its use. The safety requirements of the NASA GSFC Engineering Services Division
Safety Manual apply and shall be followed at all times.
13.1 SAFETY RESPONSIBILITY
All personnel are responsible for maintaining a safe work environment. The Test Conductor shall ensure
that appropriate safe practices are implemented, that appropriate personal protective equipment is
employed, and that operations are performed in the proper order. The HST Project Safety Engineer shall
stop any operation, condition, or act observed deemed to be unsafe to personnel, critical hardware, or
facilities. Suspended operations may not resume until the unsafe condition is corrected and safety engineer’s
approval is obtained.
13.2 CAUTIONS/WARNINGS
In this procedure, a CAUTION precedes operations which may result in damage to hardware if not followed
correctly. A WARNING precedes those operations which may result in personnel injury if followed
incorrectly.
13.3 PRE-TASK BRIEFING
Prior to the start of any of the operations contained herein, and again at each shift change, the Test
Conductor shall conduct a briefing of all involved personnel. The briefing shall include an overview of the
operation, a description of the equipment involved, and a discussion of applicable equipment and personnel
safety precautions.
13.4 SPECIFIC SAFETY PRECAUTIONS
13.4.1
Lifts
This procedure contains hazardous operations due to lifting, handling, and movement of flight
hardware. No personnel shall be allowed to work or walk beneath a crane hook that has a
suspended load. No suspended loads shall pass above flight hardware except when required for a
specific integration task related to the hardware on the crane hook. Hard hats may be removed at
the discretion of the Test Conductor if they pose an unnecessary risk to the flight hardware. Prior
to any hazardous operations a controlled area of 25-foot radius shall be established. Only essential
personnel shall be allowed in the controlled area during the operation. All communications to and
36
from the machine operators (crane, forklift) shall take place through the Test Conductor. Prior to
any lifting operations, all lifting equipment shall be inspected to verify that equipment is suitable
for use, that the rated load exceeds the anticipated load, and that the proof test certification is
current. Lifting equipment must meet the requirements of NSS/GO1740.9B. During bridge crane
operations involving flight hardware, all crane motions shall be performed one at a time and one
motion shall be allowed to completely stop prior to starting another motion. Safety observers shall
be provided when payload elements or other critical loads are being lifted, handled, and/or
transported.
13.4.2
Purge
A gaseous nitrogen purge will be maintained on the ASI by means of a dedicated Gas Purge
Purifier Cart and Console. A flexible line will run from the purge console and be attached to a
special fitting near the aperture entrance on the ASI.
13.4.3
Ammonia
Typical ASI heat pipe assemblies contain anhydrous ammonia, a substance classified as
immediately dangerous to life and health at exposure levels above 500 PPM. The safety
procedures of NSI 01-05-120, Anhydrous Ammonia Safety Operating Procedure, shall be
followed. It should also be noted that the ACS instrument contains several sets of ammonia-filled
heat pipes each charged to a pressure of 150 psi.
13.4.4
Electro-Static Discharge (ESD)
The ASI is ESD sensitive. Therefore, it shall be handled in accordance with NHB5300.4(3L)
Requirements for Electrostatic Discharge Control. All ground handling personnel shall wear ESD
wrist straps connected to the facility ground at all times. Wrist straps shall be tested daily before
entering the cleanroom.
13.4.5
Fracture Critical Hardware
The ASI is fracture critical and shall be handled by trained personnel only.
13.4.6
Contamination
The ASI is contamination sensitive and must be handled with appropriate care. This test shall be
conducted in facilities which meet or exceed Class 10,000 requirements of FED-STD-209. The
ASI shall be continuously purged with N2 gas, except that the line may be disconnected for
personnel safety reasons for a period of time not to exceed 1 hour in a 24 hour period. Purge is not
required while the ASI is under vacuum.
37