Transcript ppt

GLAST LAT Project
3 May 2005
LAT Requirements Verification in TVAC
LAT Mission Thermal Requirements are provided in four documents:
1. 433-MAR-0001, “Mission Assurance Requirements”, Sections 4.6, 10.4
2. LAT-SS-00778, “LAT Environmental Specification”, Section 11.1,2,3
3. LAT-MD-00408, “LAT Program Instrument Performance Verification Plan”, Sections 5, 7.1.1.8
4. LAT-SS-00010-02, “LAT Performance Specification – Level II (B)”, Section 5.3.11.1,2
Requirements verification by individual test is summarized in Test Segment
Chart and detailed in the LAT TVAC Test Plan.
TIM
1
GLAST LAT Project
3 May 2005
LAT Requirements Verification
LAT Thermal Environmental
TIM
Source
Parameter
Surv.
ColdCase
Nom
HotCase
Units
Earth IR on any exposed
surface
208
208
265
265
W/m2
Earth Albedo on any
exposed surfaces
0.25
0.25
0.4
0.4
Solar Flux on surfaces
exposed to +X direction
1286
1286
1419
1419
W/m2
IRD 3.2.3.5, Table 3-3
Solar flux due to 1 deg
glancing view of the sun
on +/- Y surfaces
0
0
0
6
W/m2
SPS 3.4.5.1
Orbit-average absorbed
solar flux on one Radiator
due to re-pointing
0
0
27
0
W
SPS 3.4.5.1
IRD 3.2.3.5, Table 3-3
IRD 3.2.3.5, Table 3-3
2
GLAST LAT Project
3 May 2005
LAT Requirements Verification
LAT Environmental Test Loads and Durations
Test
Test Levels/Durations
Qual
Protoqual
Acceptance
Thermal Vacuum
Cycling
Temperature5
Normal Operation
Survival
Rate6
Vacuum
Number of Cycles
Max/Min Predict ±10° C Max/Min Predict ±10° C Max/Min Predict ±5° C
Max/Min Predict ±10° C Max/Min Predict ±10° C Max/Min Predict ±5° C
<20°C/Hour
<20°C/Hour
<20°C/Hour
-5
-5
<1X10 Torr
<1X10 Torr
<1X10-5 Torr
12
4
4
5- Normal operating temperature for the LAT is 0° C to 30° C. Survival temperature is -2° C to 40° C.
6-T he CAL module must not exceed a 10° C per hour rate
TIM
3
GLAST LAT Project
3 May 2005
LAT Thermal Vacuum Testing Timeline
50
LAT Thermal-Vacuum Test Timeline
45
LAT LAT Init, Hot-PF LAT LAT Init,
Surv Aliveness CPT Surv Aliveness
Hot-TB LPT, SVAC
Open-Door CPT,
SVAC
40
Disable
35
Warm -Up
LPT
Cool-Dow n
LPT
Enable
Cool-Dow n
LPT
Warm -Up
LPT
Cool-Dow n
LPT
Thermal-Vacuum
Cycle Testing
Cold TCS Testing
Cold Operational
Thermal-Balance
Cold PFQ
Performance
Testing
Hot PFQ Perf
Cold Survival
Thermal-Balance
10
Warm -Up
LPT
Cool-Dow n
LPT
Hot TCS Testing
Bakeout
15
Hot Operational
Thermal-Balance
25
20
LAT Init,
Aliveness
Enable
Turn Off
Hot Plateau CPT
Hot Plateau LPT
Vent
Disable
Open Door Prep
Pumpdown
Temperature (deg. C)
30
Hot Plateau LPT
Open Door Close-
Open-Door CPT,
SVAC
Warm -Up
LPT
5
LAT LAT Init, Cold-PF
Surv Aliveness CPT
0
-5
Cold-TB LPT, SVAC
LAT Init,
Aliveness
RIT Temp
TCS
Turn On, Aliveness
Extreme LAT Temp
Cold Plateau LPT Cold Plateau LPT
1 May 2005 Update
Cold Plateau CPT
-10
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Time (days)
TIM
4
17
18
19
20
21
22
23
24
GLAST LAT Project
3 May 2005
Thermal Vacuum Test Segments
Individual Test Segments are Conducted in the Following Order
According to LAT Document [TBD] “LAT TVAC Test Procedures”
•
•
•
•
•
•
•
•
•
•
•
•
Chamber Pump Down
Bakeout
Hot Operational Thermal Balance
Hot Operational Thermal Control System
Hot Operational Peak Power
Hot Performance
Cold Survival Thermal Balance
Cold Performance
Cold Operational Thermal Balance
Cold Operational Thermal Control System
Thermal Cycling
Chamber Recovery
During and between certain above tests, LAT electrical performance tests will be
conducted according to the LAT “Electrical Performance Test Procedure"
TIM
5
GLAST LAT Project
3 May 2005
Chamber Pump Down
•
Electrical Performance Tests, chamber door open.
•
Pump down according to NRL procedures to <1.E-05 Torr
•
Activate LAT power buses, but LAT is powered OFF.
•
Chamber shroud cool down according to NRL procedures.
– Adjust simulated environmental temperature hardware to maintain LAT assembly between 20
and 40 degC.
TIM
6
GLAST LAT Project
3 May 2005
Bakeout
•
Adjust simulated environmental temperature hardware to maintain LAT assembly at 45 degC
•
Monitor out-gassing with Thermal Quartz Crystal Microbalance (TQCM) according to the LAT
Contamination Control Plan
•
Duration of bakeout according to TQCM criteria in LAT Contamination Control Plan
TIM
7
GLAST LAT Project
3 May 2005
Hot Operational Thermal Balance
•
Simulated environmental temperature hardware adjusted to provide hot case end-of-life (EOL)
environmental heat loads.
•
Thermal balance is attained when there is less than a 5% energy imbalance in the LAT instrument.
The RIT is expected to stabilize below +15 degC without TCS control.
•
Science verification and calibration tests are performed (power dissipation is unaltered).
•
Thermal data used to correlate the LAT systems level Thermal Math Model, which provides flight
temperature predictions.
TIM
8
GLAST LAT Project
3 May 2005
Hot Operational Thermal Control System
Hot TCS Testing consists of three tests:
1. RIT control using primary reservoir heaters and symmetric orbit average load.
– Only primary reservoir heaters enabled (redundant heaters are controlled by B-side SIU, so this
is standard).
– Primary and redundant radiator survival (antifreeze) heaters are enabled, but are expected to
remain off.
– RIT initial set point same as that achieved previously in hot operational thermal balance.
– Demonstrate RIT control by incrementally increasing RIT set point to +15 degC and then
lowering back to original level.
2. Peak power.
– Increase LAT power to peak levels (706W) for 10 minutes or until a steady state has been
achieved at the discrition of the thermal engineer.
– Monitor LAT temperatures to assure they remain within limits
3. RIT control using redundant reservoir heaters at nominal power with transient environmental
loading
– Configure LAT with only redundant reservoir heaters enabled.
– Control radiator simulated environmental temperature hardware to follow hot case temperature
profiles.
– Demonstrate RIT control by incrementally increasing RIT set point to +15 degC and then
lowering back to original set level.
– Verify ability of TCS to maintain RIT stable within +/- 7 degC under transient environmental
radiator loads.
TIM
9
GLAST LAT Project
3 May 2005
Radiator Sink Transient Temperatures – Hot Case
Radiator Sink Temperature Hot CaseTransient
20
0
-20
Temperature, deg. C
-40
-60
-80
-100
Rad_1 Ave
-120
Rad_2 Ave
-140
0
10
20
30
40
50
60
70
80
Time, minutes
TIM
10
90
100
GLAST LAT Project
3 May 2005
Hot Performance
•
Simulated environmental temperature hardware adjusted “until as many LAT temperatures as
feasible are 10 degC above their predicted operating limits.” This will be the hot proto-qualification
temperature limit.
•
Thermal stability is attained when certain monitored temperatures* are within 3 degC [TBD] of
target/goals.
•
After LAT temperatures are stable, execute a LAT Power-On/Off/On sequence according to LAT
Electrical Test Procedure.
* Note: “Certain monitored temperatures” are a set of temperature sensors that represent the
complete temperature distribution within the LAT.
TIM
11
GLAST LAT Project
3 May 2005
Cold Survival Thermal Balance
•
Simulated environmental temperature hardware adjusted to provide environment for cold survival
case.
•
Transition according to LAT TVAC Test Procedure. LAT is powered off after LPT.
– Primary and redundant survival (Grid and radiator) heater circuits are enabled.
– Primary and redundant reservoir heater circuits are enabled.
•
After reaching primary set point temperature, the primary survival heaters will cycle and the
redundant heaters will remain off since the redundant temperature set point is set below that of the
primary
•
Redundant reservoir heater is thermostatically controlled and will turn off when temperature
increases above +15 degC. Primary heater will maintain reservoir at near +40 degC at 100% duty
cycle.
•
Thermal balance attained when there is less than a 5% energy imbalance in the LAT. RIT is expected
to stabilize near - 6 degC.
•
Following thermal balance, redundant Grid and radiator survival heater circuits are enabled and
primary circuits are disabled, and environmental temperatures are decreased slightly until
redundant thermostats engage the redundant heaters. EGSE must be designed for this function
and also to override reservoir heater circuit enabling.
TIM
12
GLAST LAT Project
3 May 2005
Cold Performance
•
Simulated environmental temperature hardware is adjusted until “as many LAT temperatures as
feasible are 10 degC below their predicted operating limits.” This will be the cold proto-qualification
temperature limit.
– Not practical at cold end, since cold performance and operational limits are below cold survival
limit.
•
Thermal stability is attained when certain monitored temperatures [TBD] are within 3 degC [TBD] of
target/goals.
•
After LAT temperatures are stable, execute a LAT Power-On/Off/On sequence according to LAT
Electrical Test Procedure.
TIM
13
GLAST LAT Project
3 May 2005
Cold Operational Thermal Balance
•
Simulated environmental temperature hardware adjusted to provide cold case beginning-of-life
(BOL) environmental heat loads.
•
Thermal balance is attained when there is less than a 5% energy imbalance in the LAT instrument.
The RIT is expected to stabilize below -10 degC without TCS control.
•
Science verification and calibration tests are performed (power dissipation is unaltered)
•
Thermal data used to correlate the LAT systems level Thermal Math Model, which provides flight
temperature predictions.
TIM
14
GLAST LAT Project
3 May 2005
Cold Operational Thermal Control System
Cold TCS Testing consists of three tests:
1.
RIT control using primary reservoir heaters and symmetric orbit average load.
– Only primary reservoir heaters enabled (redundant heaters are controlled by B-side SIU, so
this is standard).
– Primary and redundant radiator survival (antifreeze) heaters are enabled, but are expected to
remain off.
– RIT initial set point same as that achieved previously in cold operational thermal balance.
– Incrementally increase RIT set point to +15 degC and then lower back to original level.
2.
RIT control using redundant reservoir heaters at nominal power with transient environmental
loading
─ Configure LAT with only redundant reservoir heater enabled.
– Control radiator simulated environmental temperature hardware to follow cold case
temperature profiles.
– Demonstrate RIT control by incrementally increasing RIT set point to +15 degC and then
lowering back to original set point.
– Verify ability of TCS to maintain RIT stable within +/- 7 degC under transient environmental
loads.
3.
TCS Parameter Upload.
– Enabling antifreeze protection at higher temperatures.
– Changing reservoir heater control band.
– Disabling an individual VCHP.
– Rejection of impossible or conflicting parameters.
TIM
15
GLAST LAT Project
3 May 2005
Radiator Sink Transient Temperatures
-50
-55
-60
-65
-70
-75
-80
-85
-90
-95
-100
RAD1 AVG
RAD2 AVG
57
60
58 8
08
58 8
56
59 8
04
59 8
52
60 8
00
60 8
48
60 8
96
61 8
44
61 8
92
62 8
40
62 8
88
63 8
36
8
Temperature (Degrees C)
Sink Temperature Beta 0 Cold Case
Time (Seconds)
TIM
16
GLAST LAT Project
3 May 2005
Thermal Cycling
•
A total of four thermal cycles will be performed consisting of
– four hot plateau
– four cold plateau
– eight transitions
•
At each plateau, electrical performance testing according to timeline and LAT Electrical Test
Procedure
TIM
17
GLAST LAT Project
3 May 2005
Chamber Recovery
•
Chamber recovery according to NRL Procedures
– Return to ambient temperature
• simulated environmental temperature hardware adjusted to maintain LAT assembly between 22 and 30
degC. RIT set point temperature adjusted accordingly.
• when ambient temperature achieved, LAT is powered off and power circuits disabled.
• all GSE power circuits disabled.
– Return to ambient pressure
•
Check room humidity to be in proper range before opening vacuum chamber door.
TIM
18
GLAST LAT Project
3 May 2005
LAT TVAC Test Segments
Test Segment
Test Segment Description
Hot Operational TCS Testing
RIT Control
Hot Op
Hot Op
Cold Surv
PumpHot Op
Hot Perf
Bakeout
Prim, Red
Peak
Transient
T-Bal, Htr
down
T-Bal
Test (QT)
Rsvr Htr's
Power
(TCS)
Func
Asymmetric
Maintain
Symmetric Symmetric
Maintain
Symmetric
transient
test article
orbit avg
orbit avg
test article
Evacuate
orbit avg
load. RIT
Survival
at 50°C
load. RIT
load. RIT
at hot QT
chamber
load without
control by
heater test
+0C/-3C for
control by
control, 10
+10C/-0C for
RIT control
prim/red rsvr
TBD hrs
prim rsvr htrs
min ?
TBD hours
htrs
ColdOperational
Operational TCS
TCS Testing
Testing
Cold
Cold Op (TCS)
RIT Control
Cold Op
Cold Perf Cold Op
Parameter
Prim, Red
Transient
Test (QT)
T-Bal
Upload
Rsvr Htr's
(TCS)
Asymmetric
Symmetric
Asymmetric
Symmetric
transient
orbit avg
transient load.
orbit avg
load. RIT
load. RIT
RIT control by
load w/out
control by
control by
prim rsvr htrs
RIT control
prim/red rsvr
prim rsvr htrs
htrs
Thermal
Cycle
4 Thermal
cycles
LAT Status
LAT Power @ RIT, W
STE Heat Sinks
Radiator Shrouds, °C
Reservoir Shrouds, °C
0
0
615
615
708
615
0
0
float,
initially
> -2
495
---
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
profile
profile
TBD
TBD
TBD
TBD
Bus Simulator, °C
--
50
50
50
50
50
50
0
0
0
0
5
0
5
0
5
0
5
0
0
0
Primary
enabled,
OFF
enabled,
OFF
enabled,
OFF
enabled,
OFF
enabled,
OFF
enabled, OFF
enabled,
OFF
Redundant
disabled
disabled
disabled
disabled
disabled
disabled
disabled
Primary
enabled,
OFF
enabled,
OFF
enabled, ON
enabled,
cycling
enabled,
cycling
enabled,
cycling
Redundant
disabled
disabled
disabled
disabled
disabled
(dis)enabled,
cycling
(dis)enabled,
cycling
disabled
Primary
enabled,
OFF
enabled,
OFF
enabled,
OFF
enabled,
OFF
Redundant
disabled
disabled
disabled
disabled
enabled,
OFF
enabled,
OFF
4.6 (4),
10.4 (9)
4.6 (1,4),
4.6.1 (5)
Grid Mass, °C
SC Heat Leak Sim's
Rad Strut per Rad, W
Flexure Sim per Flex, W
Grid Make-Up Heaters, W
--
44
float, initially float, initially float, initially float, initially
< 20
< 20
< 20
< 20
32?
float, initially
> -4
float, initially float, initially
> -2
> -2
float, initially
> -2
495
495
495
615
TBD
TBD
TBD
TBD
profile
profile
profile
profile
TBD
TBD
-10
-10
10
-10
-10
+50 to -10C
0
0
155
(dis)enabled,
cycling
(dis)enabled,
cycling
0
0
0
0
0
0
0
0
enabled,
ON
enabled,
OFF
enabled, OFF
enabled, OFF
disabled
disabled
disabled
disabled
enabled, ON
enabled,
ON
enabled,
cycling
enabled, ON
to 15ºC,
disabled
disabled
enabled,
ON
enabled,
OFF
enabled, OFF
enabled, OFF
disabled
disabled
disabled
disabled
Reservoir Heaters, W
(dis)enabled,
enabled, cycling
cycling
(dis)enabled,
disabled
cycling
Rad Anti-Freeze Heaters, W
enabled, OFF
enabled,
OFF
enabled, OFF
disabled
(dis)enabled,
cycling
(dis)enabled,
cycling
TQCM Temp
Requirements Addressed
433-MAR-0001
LAT-SS-00010-02
5.3.11.1,
5.3.11.2
LAT-SS-00778-02
11.1 (1),
11.2 (2,3,4)
LAT-MD-00408-03d
TIM
7.1.1.8 (8) 7.1.1.8 (4,8)
4.6 (2,3)
4.6 (1,4),
4.6.1 (5)
4.6 (2,3)
5.3.11.1,
5.3.11.2
11.2 (4)
11.2 (4)
4.6 (4),
4.6.2
(6,7,8)
4.6 (1,4),
4.6.1 (5)
5.3.11.1,
5.3.11.2
11.2 (4)
11.3 (5)
11.1 (1),
11.2 (2,3,4),
11.3 (5)
11.3 (5)
11.1 (1),
11.2 (2,3,4)
7.1.1.8 (5,8)
7.1.1.8
(4,5,8)
7.1.1.8
(5,8)
7.1.1.8
(4,8)
19
11.2 (4)
11.2 (4)
5 (1),
7.1.1.8
(2,3,6,7,8)
GLAST LAT Project
3 May 2005
TVAC LAT Cool Down Comparison
Cool Down Scenarios During LAT TVAC Cycling
80
Grid
Time to Reach Cold Extreme Temperature, Hours
70
CAL
60
TKR
50
40
30
20
10
0
1-Ref,
Power ON,
Sinks @90°C,No
HEX
2-Ref,
Sinks @ 150°C
3-Ref, with
HEX
4-Pwr OFF, 5-Pwr OFF, 6-Pwr OFF,
6a-Pwr
6b-Pwr
6c-Pwr
7-Pwr OFF,
Resrv. Heat Resrv. Heat Resrv. Heat
OFFOFFOFFResrv. Heat
ON
ON, with
OFF
ON@25C,
ON@15C,
ON@8C,
OFF, with
HEX
Resrv. Heat Resrv. Heat Resrv. Heat
HEX
OFF, Sinks OFF, Sinks OFF, Sinks
@-150°C
@-150°C
@-150°C
Cool Down Scenario
TIM
20
GLAST LAT Project
3 May 2005
Simulated Environmental Temperature – Cal Rod Concept
“Picture Frame” baffles; polished
aluminum with holes for Cal Rod
sockets
Height of
ACD
Height of
radiator
6”
6” – 8”
Support structure, low
e with heaters or
blanketed;
15” – 20” from radiator
Width of radiator
TIM
21
GLAST LAT Project
3 May 2005
LAT TVAC Personnel Requirements
Category
1
2
3
4
5
6
7
8
9
10
Description
Test Conductor (alternate between Cat 2 and Cat 4 or 5)
Thermal Engineer
Chamber/Facility Engineer
LAT Operations/Systems Engineer
LAT Electrical/Performance Scientist
LAT Software Engineer
Subsystem Specialist, ACD
Subsystem Specialist, TKR
Subsystem Specialist, CAL
Subsystem Specialist, E-Box/Cabling
30 day test x 3 shifts/day = 90 shifts
Cat 1 – 3: all shifts
Cat 4: all shifts initially, part time during cycling
Cat 5: all shifts initially, then as necessary, always during electrical performance tests
Cat 6: all shifts initially, then as necessary
Cat 7 – 10: all shifts initially, then during electrical performance tests
Estimated total effort: 400 shifts x 8 hr/shift = 3200 hrs
TIM
22