Transcript Section 2.1 - Requirements

GLAST LAT Project
Gamma-ray Large
Area Space
Telescope
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
GLAST Large Area Telescope:
Mechanical Systems Peer Review
March 27, 2003
Section 2.1 – Requirements &
Compliance
Leonard Lee
SLAC
Systems Engineer
[email protected]
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
1
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Topics
Agenda
• Requirements flow down
• Doc status
• Key Requirements & compliance
• Requirement changes since dPDR
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
2
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
LAT Requirements Flow-Down
Mission
Science
Requirements
Document
433-SRD-0001
Mission System
Specification
433-SPEC-0001
LAT
LAT-SC Interface
Requirements
Document
433-IRD-0001
Design Specification
Subsystem
LAT-SS-00010
Mechanical
Subsystem
Specification
LAT-SS-00115
Interface
Rqmts
Mission
Rqmts
Science
Rqmts
LAT Performance
Specification
LAT IOC/MOC/
SSC Interface
Control
Documents
LAT
Environmental
Specification
LAT-SS-00778
TCS Performance
Specification
LAT-SS-00715
Ground System Rqmts
Interface
Rqmts
LAT IOC
Performance
Specification
LAT-SS-00015
LAT-SC Interface
Control Document
Trigger & Dataflow
Subsystem
Specification
LAT-SS-00019
TKR Subsystem
Specification
ACD Subsystem
Specification
LAT-SS-00017
LAT-SS-00016
Radiator Design
Specification
LAT Dataflow
Specification
LAT TKR Design
Specification
LAT-SS-00394
LAT-SS-00285
LAT-SS-00134
X-LAT Plate
Design
Specification
LAT-SS-01240
LAT Trigger
Specification
LAT-SS-00284
LAT Readout
Electronic
Specification
LAT-SS-00152
Grid Box Design
Specification
LAT Flight SW
Specification
LAT-SS-00775
LAT-SS-00399
Document: LAT-PR-0XXXX
Power
Subsystem
Specification
LAT-SS-00136
CAL Subsystem
Specification
Tower Power
Supplies
Specification
LAT-SS-01537
CAL Design
Specification
LAT-SS-00018
LAT-SS-00210
LOF
Subsystem
Specification
LAT-SS-00021
SAS
Subsystem
Specification
LAT-SS-00020
LAT Operations
Facility
Specification
LAT-SS-01783
SAS Design
Specification
LAT-SS-00505
ACD Design
Specification
LAT-SS-00352
Section 2.1 Requirements & Compliance
3
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Requirements Flow-Down and
Documentation Status
LAT Perf Spec
LAT-SP-00010-1
31 Aug 2000
LAT Stay-Clear
Drawing
LAT-DS-00040-5
LAT Envir. Spec
LAT-SS-00778-1
10 Feb 2003
Subsystem ICD’s
Mech Systems
Subsystem Spec
LAT-SS-00115-2
Subsystem IDD’s
X-LAT Design
Spec
LAT-SS-00xxx-1
X-LAT Plate SCD
LAT-DS-01247-1
Radiator Design
Spec
LAT-SS-00394-1
Mid-Plate SCD
LAT-DS-01257-1
Grid Box Design
Spec
LAT-SS-00775-1
LAT Thermal
Design Param’s
LAT-TD-00224-3
Thermal Control
Sys. Perf. Spec
LAT-SS-00715-1
LAT Dissipated
Power Summary
LAT-TD-00225-3
LAT Instrument
Layout Dwg
LAT-DS-00038-3
Radiator IDD
LAT-DS-01221-1
Document
LAT-SS-00115-2: Mechanical Systems Subsystem
Specification—Level III Specification
LAT-SS-00xxx- 3: X-LAT Level IV Specification
LAT-SS-00394-1: Radiator Level IV Specification
LH/RH Down
Spout Heat Pipe
SCD
LAT-DS-01392-1
LAT-DS-01393-1
Status
Rev 2 released, Rev 3 in work
Final draft out for review
Final draft out for review
LAT-SS-00715-1: Thermal Control System Performance Specification
First draft out for review
LAT-SS-00775-1: Grid Box Level IV Specification
LAT-DS-01221-1: Radiator IDD
LAT-DS-01247-1: X-LAT Plate Source Control Drawing
LAT-DS-01257-1: Mid-Plate Source Control Drawing
Final draft out for review
Rev 1 complete;out for review
Rev 1 complete;out for review
Rev 1 complete;out for review
Document: LAT-PR-0XXXX
Top Flange Heat
Pipe SCD
LAT-DS-01393-1
Section 2.1 Requirements & Compliance
4
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Requirement Changes since dPDR
•
•
The LAT Environmental Specification(LAT-SS-00778-01-D8) is a new
requirements document for all subsystems including the LAT
Mechanical Systems
– Resulting Requirement Change(s)
• Grid Box Static-Equivalent Accelerations
• Radiator Static-Equivalent Accelerations
• Out-of-plane Distortion for the TKR, CAL, ACD & S/C
Subsystems to Grid Interfaces
• CAL- Grid Interface Loads
• Radiator Interface Loads
• Grid Box Random Vibration Spectra
• Grid Box Temperature Limits
• Radiator Temperature Limits
Changes have been accommodated in the design, except Radiator is
still evaluating impacts of new environmental loads. The current
design is expected to be acceptable.
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
5
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Key Mechanical Systems Requirements 1
Sect
8
8.1.
Requirement
Design
329.3
15.7
8.4.
Y
I
LAT-TD00125-1
Y
I
(derived)IR
D 3.2.2.5
Y
I
Y
I
Y
I
Y
I
Y
I
Y
I
Center of Gravity
C.G. of Mechanical Sys tem s les s than z = -530.2 m m
8.3.
Compliance
Comply Method Req Source
Configuration
Mass
The total m as s of Mechanical Sys tem s < 345 kg
8.2.
Margin
Stay-Clear Volume and Dimensions
Mechanical Sys tem s s hall s tay, and keep other s ubs ys tem s within the
IRD envelope
Ok
Max Radiator area s hall be 5.4 m 2
5.2 m 2
Radiators configured as 2 s eparate Radiators
Ok
Each Radiator no wider than 1.85 m
1.85 m
Radiators pos itioned according to IRD Appendix A
>1.89 m
s ep
Mount point for SC s upport as s hown in IRD Appendix A
Ok
0
0
1.895 m
IRD
3.2.2.1
IRD
3.2.3.4.1
IRD
3.2.3.4.1
IRD
3.2.3.4.1
IRD
3.2.2.3
IRD
3.2.2.3
Power
Ok
27.6W+30
% control
m argin
Y
T, A
(derived)LA
T-TD00125-1
When off, orbit-average s urvival heater power < 300 W AT 27 V m in
Ok
199W
+30%
Control
Margin
Y
T, A
(derived)
IRD
3.2.4.1.7.6
When off, orbit-average s urvival heater power < 350 W AT 29 V m ax
Ok
Y
T, A
When off, s urvival heater peak power < 350 watts
Ok
Y
T, A
LAT m ain bus voltage range of 27 V – 29 V, DC
Ok
Y
D
LAT s urvival bus voltages (2 bus es ) in the range of 27 V – 29 V, DC
Ok
Y
D
When on, Radiator VCHP heater power < 48 W
(derived)IR
D
3.2.4.1.7.6
IRD
3.2.4.1.7.6
IRD
3.2.4.1.3.1
IRD
3.2.4.1.7.2
LEGEND Y: Design Compliant, P: Design Partially Compliant, WC: Will Comply, A: Analysis, D: Demonstration, I: Inspection, S: Similarity, T: Test
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
6
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Key Mechanical Systems Requirements 2
Sect
8
8.5.
Requirement
Design
Compliance
Comply Method Req Source
Configuration(Cont'd)
Stiffness
Fixed-bas e firs t-m ode > 50 Hz
8.6.
Margin
Y
T
IRD
3.2.2.8.1.2
OK
Y
D
derived
from IRD
3.2.5.4
OK
Y
A
IRD
3.2.1.5.4
Ok
Y
D
IRD 3.2.1.5
Ok
Y
T, A
IRD 3.2.3.7
Ok
WC
I
Ok
Y
I
Ok
WC
I
55.5 Hz
11%
Provisions for Integration and Test
LAT Integration Accom m odations
Provide purge plena to allow cons tant ins ide-out purging of the LAT
Ground Environm ent
Com ponents capable of being s tored and operated in a clas s 100,000
environm ent
Com ponents capable of functioning and being s tored in ground am bient
environm ents
Tes t Provis ions
During Obs t-vac, TCS capable of full functionality "lying on its s ide"
Obs ervatory Integration Provis ions
After Obs int., connectors capable of de-/re-m ating w/out requiring other
de-m ates
LAT capable of m ating/de-m ating to the SC without de-m ating any
internal LAT cables
LAT ground tes t connectors eas ily acces s ible for de-/m ating after LAT
integration
IRD
3.2.4.6.3
IRD
3.2.4.6.4
IRD
3.2.4.6.5
LEGEND Y: Design Compliant, P: Design Partially Compliant, WC: Will Comply, A: Analysis, D: Demonstration, I: Inspection, S: Similarity, T: Test
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
7
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Key Mechanical Systems Requirements 3
Sect
Requirement
Design
Compliance
Margin Comply Method Req Source
9
LAT Alignment
9.1. Alignment
Maintain subsystem alignment to 30 arc-minutes after ground testing
and launch
During launch, maintain subsystem alignment to less than 5 arc-minutes
During launch, prevent subsystem modules from colliding or touching
each other
9.2. Alignment Stability
10
P
I
derived
Y
A
derived
Y
A
derived
Maintain TKR alignment to < 7 arc-seconds, 1 s radial, during normal
LAT operation
4.1 arc2.9arcsec peaksec+5s
to-peak
T
MSS
(TBR), 3.3.1.11.1.
A
2
MSS
A
3.1.4.2.1.1
Y
Maintain TKR alignment to < 7 arc-seconds, 1 s radial, during all slews
Ok
Y
Capable of exposure to static launch loads
Ok
Y
T, A
Capable of withstanding static loads in thrust and lateral axes
simultaneously
Ok
Y
A
Structural Load Environment
10.1. Structural Loads
IRD
3.2.2.8.2
IRD
3.2.2.8.2
LEGEND Y: Design Compliant, P: Design Partially Compliant, WC: Will Comply, A: Analysis, D: Demonstration, I: Inspection, S: Similarity, T: Test
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
8
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Key Mechanical Systems Requirements 4
Sect
11
Requirement
Design
Compliance
Margin Comply Method Req Source
Thermal Environment and Heat Loads
11.1. Process and Interface Heat Loads
Capable of dissipating up to 650 W of LAT process power, indefinitely
602W
LAT+48W
Rad@17d
egC
Capable of dissipating as little as 500 W of LAT process power,
indefinitely
475W@10 degC
5 degC
calc+8de
gCoperati
ng
25W+50
% Rad
control
authority
Capable of dissipating 5 W per Radiator heat conducting in from the SC
supports
Y
T, A
same as
IRD
3.2.4.1.1
Y
T, A
derived
from LATTD-00225
Y
T, A
same as
IRD
3.2.3.4.3
same as
IRD
3.2.4.1.2
Capable of dissipating 750 watts LAT process power for 10 minutes,
maximum
750W for
20
10min,8
min@<T( degC
max)
Y
T, A
Capable of normal operation when loaded by 75 W/Rad of heat from SC
solar arrays
159W/Ra
84 W/Rad
d
Y
T, A
Capable of normal operation with Rad-Solar Array view factor = 0.1
Ok
Y
A
Y
T, A
Y
T, A
Capable of dissipating 5 watts of heat conducting through LAT-SC
mounts
Capable of dissipating heat from the SC through 2 layers of MLI [10C<T(SC)<+50C]
same as
IRD
3.2.3.4.5
same as
IRD
3.2.3.4.5
same as
IRD 3.2.3.3
same as
IRD 3.2.3.3
LEGEND Y: Design Compliant, P: Design Partially Compliant, WC: Will Comply, A: Analysis, D: Demonstration, I: Inspection, S: Similarity, T: Test
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
9
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Key Mechanical Systems Requirements 5
Sect
Requirement
Design
Compliance
Margin Comply Method Req Source
11.2. Interface Temperatures
11.3. Environment Heat Loading and Orbital Parameters
The LAT shall be in an initial orbit of 550 km
Y
A
Orbit range of 450 km min to 575 km max
Y
A
Maximum inclination of 28.5 degrees
Y
A
Maximum eccentricity of 0.01
Y
A
Provide thermal control with LAT pointed 2pi/24/7/365 during any normal
LAT mode
Y
T, A
Capable of maintaining thermal control during exposure to IR, Albedo,
Solar fluxes
Y
T, A
Y
T, A
Y
T, A
Capable of maintaining thermal control when exposed to solar flux from
SC re-points
Capable of maintaining survival temp's while one Radiator is fully
exposed to sun
Ok
derived
from MSS
3.1.1.4
derived
from MSS
3.1.1.4
derived
from MSS
3.1.1.4
derived
from MSS
3.1.1.4
derived
from MSS
3.3.2.3
derived
from IRD
3.2.3.5
derived
from SPS
3.4.5.1
derived
from (TBD)
LEGEND Y: Design Compliant, P: Design Partially Compliant, WC: Will Comply, A: Analysis, D: Demonstration, I: Inspection, S: Similarity, T: Test
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
10
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Key Mechanical Systems Requirements 6
Sect
Requirement
Design
Margin
Compliance
Comply Method Req Source
11.4. Thermal Hardware Configuration
12
All Mechanical Sys tem s external s urfaces s hall be ins ulated with MLI
All Mechanical Sys tem s MLI blankets s hall have an effective em is s ivity <
0.03
On-Orbit Environment
WC
I
IRD 3.2.3.3
Y
S
IRD 3.2.3.3
Capable of operation in radiation environm ent for the life of the m is s ion
WC
S
WC
S
Y
A
Y
A
WC
D
Elec com ponents and the TCS able to tolerate ins tantaneous rem oval of
power
Y
D
Survival heater power not required during norm al operations of the LAT
Y
D
Y
D
WC
D
TCS s urvival heaters electrically is olated from each other and chas s is
Y
I
TCS pas s ively controls s urvival heaters
Y
D
TCS tolerates s urvival bus DC voltages from 0 to 42 V
Y
D
WC
D
Capable of operation in the GLAST atom ic oxygen environm ent(
9.72E+21atom s /cm 2) for the life of the m is s ion
Capable of norm al operation in m icrom eteoroid environm ent for the life
of the m is s ion
Capable of operation in the debris environm ent for the life of the m is s ion
13
MSS
3.3.5.1.1
LAT
Environ.
Spec.12.4
MSS
3.3.5.1.3
MSS
3.3.5.1.4
Electrical System
11.5. Grounding and Shielding
TCS com ponents s hall m eet EMI requirem ents per 433-RQMT-0005
IRD 3.2.4.3
11.5. Thermal Control Operations
Survival power us ed only for heaters and as s ociated pas s ive control
circuitry
TCS capable of handling continuous s im ultaneous power to all
redundant power bus es
TCS capable of trans itioning from any m ode to s afe m ode in les s than 10
s econds
derived
from IRD
3.2.4.1.6.5
IRD
3.2.4.1.7
IRD
3.2.4.1.7.2
IRD
3.2.4.1.7.3
IRD
3.2.4.1.7.4
IRD
3.2.4.1.7.7
IRD
3.2.4.1.3.2
derived
from IRD
3.2.8.2
LEGEND Y: Design Compliant, P: Design Partially Compliant, WC: Will Comply, A: Analysis, D: Demonstration, I: Inspection, S: Similarity, T: Test
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
11
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Key Mechanical Systems Requirements 7
Sect
14
Requirement
Design
Venting, Volatiles, and Particulates
All air and particulates vented down and away from the LIP during ascent
15
Compliance
Margin Comply Method Req Source
Y
I
derived
Y
I
derived
from CCP
Y
S
Probability of a fatal failure of TCS shall be no greater than 0%
N
A
No single-point failure of any kind shall jeopardize the mission
Y
A
Components shall be fully redundant
Y
A
WC
A
Y
D
Components, assemblies to meet LAT-MD-00404, "LAT Contamination
Control Plan."
Reliability and Redundancy
Components and assemblies capable of functioning for five years after
launch
No two credible failures shall result in loss of life or damage
The TCS shall have redundant survival heaters
Design, fabrication, and testing shall meet all req's of the MAR
16
I
MSS
3.1.1.2.2
derived
from (TBD)
derived
from IRD
3.2.8.1
derived
from IRD
3.2.8.1
derived
from MSS
3.3.1.5.1
same as
IRD
3.2.4.1.7.1
derived
from MAR
Analytical Modeling
Steady-state and transient thermal analysis shall use only TSS and
SINDA
Ok
Y
I
same as
IRD
3.2.3.6.1
LEGEND Y: Design Compliant, P: Design Partially Compliant, WC: Will Comply, A: Analysis, D: Demonstration, I: Inspection, S: Similarity, T: Test
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
12
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
Key Mechanical Systems Requirements 8
Sect Requirement
16
Analytical Modeling
Design
Compliance
Margin Comply Method Req Source
Steady-state and transient thermal analysis shall use only TSS and
SINDA
Ok
Y
I
Develop and maintain hot-case and cold-case thermal models
Ok
Y
I
Generate a reduced thermal model of the LAT
Ok
Y
I
Responsible for the design, analysis, and performance of the LAT
thermal system
Ok
Y
I
Structural factors of safety in accordance with GEVS-SE Rev A.
Ok
Y
I
All design and analysis models shall use SI units
Ok
Y
I
Use metric system
Ok
Y
I
All interchanges external to the LAT shall use the Spacecraft Coordinate
System
Ok
P
I
same as
IRD
3.2.3.6.1
derived
from IRD
3.2.3.6.2
derived
from IRD
3.2.3.6.2
derived
from IRD
3.2.3.1
same as
IRD
3.2.2.8.3
derived
from IRD
3.2.1.4
derived
from IRD
3.2.1.6
same as
IRD 3.2.1.1
LEGEND Y: Design Compliant, P: Design Partially Compliant, WC: Will Comply, A: Analysis, D: Demonstration, I: Inspection, S: Similarity, T: Test
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
13
GLAST LAT Project
DOE/NASA Mechanical Systems Peer Review, March 27, 2003
End of
Section 2.1
Document: LAT-PR-0XXXX
Section 2.1 Requirements & Compliance
14