introduction to assembly, integration & verification (aiv)
TRANSCRIPT
Introduction to Assembly, Integration & Verification (AIV)
Part 2
By Nathanan Sachdev
36
How do we perform
assembly, Integration
& Verification?
AIT/EVT overview
Typical Test phases
Generic Test flow
AIT testing breakdown
EVT testing breakdown
Test tracking and documentation
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Generic Phases for spacecraft Development
Bid Phase KO PDR CDRConceptual &
Preliminary DesignDetailed Design
ARRModule readiness
for AITTRRTest readiness FRR
Testing and prep for
Flight readiness
Launch IOTR OperationsCommissioning
Conceptual design
System Preliminary design
activities
Design Development plans
Initial CONOPS
Preliminary mission analysis
Architectural design
System Preliminary design activities
Draft Verification matrix
Sub system critical design
FDIR
CONOPS
Unit builds
AIT support
EVT testing
Spacecraft level testing
Launch campaign planning
User manuals
Commissioning plans
Operations rehearsals
Launch site activities
Pre- launch
Unit Tests
FDIR/ ISFT testing
Satellite Hardstack
LEOP
Platform commissioning
Payload commissioning
Initial design/ customer
requirements
Proposal generation
Cost pack generation
Bid sign off etc.
Ops support
Anomaly support
AIT
Ends
S/C Dev phase
S/C AIT phase
AIT
Starts
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General AIT Process (1)
● The AIT process takes modules, software & mechanical components & transforms the
m into a stable, integrated spacecraft ready for EVT
○ It is the real-world implementation of systems engineering and the start of the execution & for
mal recording of the verification process
● AIT testing starts following the completion of module level tests, Module Readiness Re
view (MRR) and prior to the EVT campaign
● Each module engineer supports AIT throughout their module test at AIT level
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General AIT Process (2)
AIT tests are carried out in the AIT cleanroom facility under the responsibility of the AIT Lead
○ All integration & testing is facilitated by the AIT team
■ Controls Spacecraft configuration
● Spacecraft build schedule
● Module Integration Schedule
● Software deployment schedule
■ Test scheduling
■ Coordination of activities with other facility and equipment users
■ Designation of spacecraft operators (personnel from AIT team)
○ The Spacecraft operator is responsible for
■ Operating and commanding the spacecraft at all times
■ Safe operation of the Spacecraft and associated EGSE and MGSE
■ Safety of personnel working on and located around the spacecraft
■ Relays with module engineer to facilitate module operation at AIT level
The Module Engineer is responsible throughout AIT for testing their module & providing support to AIT at system level testing
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Detailed AIT Test Flow
• Generic AIT test flow is
shown
• AIT is responsible for all
phases
• Spacecraft AIT flow only
may be tailored and
optimized to each SC
development project
• Environmental testing is carried out to ensure functionality at
designed operating environment
• System end to end test utilizes flight software to ensure
functionality of the designed user scenarios
• Additional AIT testing is carried out to ensure integrate
functionality prior to launch.
Platform Harness
Design &
Manufacturing
Platform harness
verification
Preparations & G
SE integration
Platform MGSE
assembly &
Certification
EGSE Design &
Manufacturing
Environment,
Test equipment
& Tooling
preparation
EGSE
Commissioning
A
R
R
Module integration
(Flat-sat)
Initial mechanical
assembly
Spacecraft AIT
Ambient pressure
thermal cycling
Low level
vibration test
Post vibe inspection
& testSC HardStack
Integrated system
functional test
Environmental Test
campaign EVT
VIB,TVAC,EMC
Spacecraft EVT & Testing
Systems level
Testing
Pack and ship
Spacecraft
Launch campaign
TRR
FRR
Launch
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AIT Preparations Overview (1)• Prior to start of the AIT phase multiple
GSEs and SC harness must be defined
and allocated.
– Harness is designed with respect
to modules ICD and manufacture
d to the required standard.
– AIT facility and required test equi
pment allocated based on
top level requirements
– GSE designed based on required
interfacing to the SC
• These tasks and their result is the main
influence that affects the Go/No-Go
Decision made by the Project manager
/AIT lead.
Platform Harness
Design &
Manufacturing
Platform harness
verification
Preparation & GSE integration
Platform MGSE
assembly &
Certification
EGSE Design &
Manufacturing
Environment,
Test equipment &
Tooling
preparation
EGSE
Commissioning
ARR
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Spacecraft AIT Overview (1)• Early entry into AIT allows as much testing
as possible to be conducted at a more repre
sentative, integrated level
– AIT testing is conducted throughout
the sofstack and hardstack phase
– AIT Module level testing is typically a
subset of bench level tests
– Reduced version of module functional
ity bench test
– Subsystem Interfacing functionality is
focused
– Redundancy functionality is tested
– Flight harness interface
derisking/debugging
Module integration
(Flat-sat)
Initial mechanical
assembly
Spacecraft AIT
Ambient pressure
thermal cycling
low level
vibration test
Post vibe
inspection & test
Integrated system
functional test
SC hardstack
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Spacecraft AIT Overview (2)
• Testing builds up in complexity and the layered approach allows for:
– Early risk reduction
– The build up of operational hours on the critical units in a representative environment
• Wherever possible, all software is exercised in AIT as close to how it will be operated in orbit
– Detailed functional testing to occur at an integrated satellite level prior to SEET
– The use of flight interfaces and databases• Where module flight interfaces are required, consideration must be given to test limitations for any
given module if another module is not present
– Units to be tested at regular points throughout AIT
– Repeat testing building up levels of confidence the equipment functions as expected
– If any negative trends are evident, then corrective actions can be taken
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Spacecraft EVT Overview (1)
• Prior to start of the SC EVT phase a test
readiness review is conducted to ensure
SC, GSEs, and facility readiness.
– The environmental test campaign is te
sted based on actual environments the
SC will encounter
• Shake (VIB)
• Bake (TVAC)
• Radiate (EMC)
– Provides confidence for SC to survive
launch and validate functionality in
designed operating environment
– Deviation from standard test within ca
mpaign is dependent on design and
requirements.
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Environmental
Test campaign
EVT
VIB,TVAC,EMC
Spacecraft EVT & Testing
Systems level
Testing
Pack and ship
Spacecraft
Launch campaign
TRR
FRR
Launch
45
Spacecraft EVT Overview (2)
46
• System End to End testing is completed to
ensure full system level functionality of the
SC post EVT testing
– The systems testing may include but
not limited to:
• ISFTs
• System End to End test
• Launch campaign mainly relates to the
activities carried out at the launch site
– SC checkout and testing
– Propulsion filling
– SC integration to the separation
system and the Launch Vehicle
Environmental
Test campaign
EVT
VIB,TVAC,EMC
Spacecraft EVT & Testing
Systems level
Testing
Pack and ship
Spacecraft
Launch campaign
TRR
FRR
Launch
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AIT (SC functionality Verification) (1)
● Our main objective is to always verify / validate requirements at the highest level of
integration possible
○ Provides verification in the most operationally representative configuration
○ If unachievable at spacecraft level then the level of integration reduced until verification possible
○ Important to undertake ‘confidence testing’ prior to formal ‘run-for-record’ so no issues discovered late in the programm
e
● Verification can occur at any phase:
○ FM unit/module tests can take place on the bench and/or integrated into the satellite
○ Sub-System tests such as payload chain and propulsion system tests
○ Space segment tests such as FDIR and integrated system tests (ISFTs)
○ EVT (e.g. during TVAC, Mechanical and EMC)
○ System end-to-end test
○ In orbit test (e.g. during payload commissioning)
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AIT (functionality Verification) (2)
● System engineer / technical lead and AIT need to agree the verification approach
with the respective WPM
○ Helps to define the test programmes
○ Determine the ground support equipment required
○ This is done early during the conceptual/preliminary design phase
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AIT/EVT phase activities (Spacecraft AIT) ● Module electrical assembly Integration (Flat-sat config)
– DC and RF harnessing (supported by AIT Harness engineer)– Module initial integration – Integrated module Unit and sub-system testing
(supported by AIT operator)
● Flat sat configuration thermal cycling test– Test module at hot and cold temperatures
● Satellite mechanical assembly (softstack & Hardstack)
– SC structure build
(Supported by Mechanical design team)
– Vibration test and post vibration inspection
● Integrated systems testing
– Demonstrate baseline functionality and performance via flight software
– Subsystem interface testing
Module integration
(Flat-sat)
Spacecraft AIT
Ambient pressure thermal cycling
Low level
vibration test
Post vibe inspection
& test
SC hardstack
Integrated system
functional test
Environmental Test
campaign EVT
VIB,TVAC,EMC
Spacecraft EVT & Testing
Systems level
Testing
Pack and ship
Spacecraft
Launch campaign
TRR
FRR
Launch
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AIT/EVT phase activities (Spacecraft EVT)
Spacecraft EVT
● Qualification/Acceptance testing - Demonstrated at EVT campaign
– Quality of workmanship
– Integrity of spacecraft for flight acceptance
– Baseline functionality
– Functionality at environmental extremes
● Systems level testing
● General shipping and handling of Spacecraft throughout
● Preparation of satellite for Launch activities
Module integration
(Flat-sat)
Spacecraft AIT
Ambient pressure thermal cycling
Low level
vibration test
Post vibe inspection
& test
SC hardstack
Integrated system
functional test
Environmental Test
campaign EVT
VIB,TVAC,EMC
Spacecraft EVT & Testing
Systems level
Testing
Pack and ship
Spacecraft
Launch campaign
TRR
FRR
Launch
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Spacecraft AIT Testing (Softstack) (1)
● AIT Flat sat integration
– As modules can suffer delays, AIT can be opportunistic
– Plan activities based around what is available but be prepared to adapt to changing circumstances
• AIT can start without all modules being present• Most modules can be functionally tested with only a power
system, harness and OBC present as the core system• Required GSEs is used throughout the AIT phase to support
interfacing with the modules
Primary Module
(Power systems /
Harness)
Other Independent
modules
(AOCS, Payloads, etc.)
Required GSEs
(EGSE)
Generic flatsat testing setup
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Spacecraft AIT Testing (Softstack) (2)
● Integrated Module Testing in AIT (Softstack)
– Performed throughout the entire AIT phase
– Carried out by the spacecraft operator with support from the Module engineer
– AIT Testing at softstack phase focuses on:
• Module integrates successfully as part of a complete system
• expected Integrated Functionality as part of each subsystem system
• Interfaces between connected modules and their function
• Performance is as expected as part of a system
• Raw module telemetry conversion equations are checked and displayed in an optimized format
• TT &TC database checked and operational for each module
– The Module tests carried out are defined by the Modules Test Plan and the results recorded in the Module Test
Results and TVM (Test verification matrix)
– The Spacecraft TVM will also reflect that these tests have been carried out at ambient temperature
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Spacecraft AIT Testing (Sub-system) (1)
● Sub-System testing criterion – System engineer & AIT lead work together to define set of functional hardware/software that can be tested
• Integrated System Function Testes (ISFT)
– Most ISFTs are conducted at ambient temperature
– Some ISFTs are executed during ambient pressure thermal cycling, as they are dependent of the
operating temperature
• System engineer decides on the verification aspects that needs to be tested
• AIT engineer contribute by providing recommendations based on the current status of the GSEs and
the Spacecraft
– Test feasibility based on spacecraft configuration
– Test feasibility based on module and software readiness
– Test constraints imposed by GSEs state
– Schedule and SC availability limitations
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Spacecraft AIT Testing (Sub-system) (2)
● Sub-System testing criterion (cont.)
– AIT input regarding current status of Spacecraft shapes the subsystem testing flow to allow maximum test efficiency while maintaining a balance between testing and other task around the spacecraft.
• This allows the SC independent functionality to be tested over the AIT phase between other tasks
in the schedule
• Flushes out issues at subsystem level prior to the full system testing at the EVT phase.
• Allows performance criteria to be verified at system level based on the systems engineer
discretion
• Builds confidence in the subsystem level interfacing software
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Spacecraft AIT Testing (Thermal cycling) (1)● Thermal cycle test acts as a verification process for verify module functionality at hot and cold temperatures at
ambient pressure.
– The primary objectives of the thermal cycling is to
• Test the spacecraft structure and modules at thermal extremes
– AIT process for thermal testing is determined by determined by the top level requirements
• Thermal extremes are defined by thermal analysis based on module expected operating environment
temperature
• Generally, LEO SC are qualified to survive between -65 and +125 degrees celsius
(Dependent on orbit height and operating requirements)
• Since all the module are tested together as an integrated system. The testing temperature may be constraint by
the module/unit with the smallest thermal range.
– Some subsystem level function & performance can be tested over temperature extremes
• Tests function and performance criteria in relation to temperature
• Indirectly tests module survivability and actual limits (Usually done at module level)
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Spacecraft AIT Testing (Thermal cycling) (2)● Different levels of Thermal cycling in AIT
– Flat Sat thermal cycling test
• Derisk flight harness used to interface between modules
• Test Integrated module functionality at AIT level in hot and cold conditions
• Perform 3 operative cycles hot-cold cycles with a non operative cycle.
– Non-operative cycle is generally done at a wider temperature range
– SC level thermal cycling test
• Derisk the spacecraft structure at hot and cold conditions
• Test the S/C as an integrated system as part of systems level tests
• Perform interface testing for payloads and functionality validation for modules that may not have been integrated
at flatsat level
• All spacecraft subsystem are expected to be tested at this level
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Environmental testing Campaign Overview
● Generally spacecraft undergo acceptance level environmental test campaign
– The primary objective of EVT testing is to assure that the spacecraft can survive the launch and make it to desired orbit
while maintaining both structural and functional integrity
– Acceptance levels are usually derived from Launch vehicle interface control document
● The scope of the EVT test campaign is dependent of the design of the satellite, Launch vehicle and specific top level
requirements
– A generic EVT test campaign usually consists of the following:
• Mass properties measurement
• Mechanical Vibration test (To simulate launch phase)
• Thermal vacuum testing (To simulate operation in space environment)
• Electromagnetic compatibility testing (demonstrate and de-risk electromagnetic compatibility)
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Environmental testing (Vibration testing)
● Vibration testing is typically the first EVT testing as it is the first environment that the spacecraft has to survive during launch.
– The primary objective of Vibration testing is to assure that the spacecraft can survive the launch and make it to desired orbit
while maintaining both structural and functional integrity
– Acceptance levels are usually derived from Launch vehicle interface control document
– Vibration testing covers the spacecraft in a flight representative configuration and is tested to predict loads imposed by the
launch vehicle.
● Vibration Test are generally performed on a vibration shaker which is capable of producing the loads required for the
acceptance levels and duration as per the launch vehicle vibration mask.
● The vibration test planning is done by the mechanical analysis engineer and is supported by AIT and systems engineer.
– Additional task such as FE model , test result analysis and validation is also covered by the mechanical analysis engineer
– AIT engineer will support with spacecraft configuration, handling and setup in preparations for the test
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Environmental testing (Vibration testing) (cont.)● The spacecraft is tested in all three spacecraft axis
● Generally vibration testing can be broken down into three functional blocks
– Low level sine survey
• Locates natural resonance peaks in the Spacecraft structure
• Always performed before proceeding shaking the spacecraft at a higher level
– Sine Vibration
• To demonstrate structural survivability at high level sine vibration environment
– Random Vibration
• A representative vibration spectrum based on the launch vehicle
● Vibration testing verifies the following:
– Spacecraft structural integrity when subjected to loads seen during flight
– Finite element model for the spacecraft
– System level functionality and overall spacecraft health
• Post vibration the spacecraft health check will be carried out by AIT to ensure that modules have been dama
ged from the test
• Additional inspection for each module will be carried out
• Module engineer must identify area of concern or functionality that may be impacted as a result of vibration a
nd these concerns must be addressed by testing each module with a dedicated test plan.
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Environmental testing (Thermal Vacuum)
● Thermal cycling in vacuum is typically the second EVT testing as it simulates SC in vacuum once released from LV in space.
– The primary objective of TVT testing is to assure that the spacecraft can be
operated as desired in space once separated from the LV (cold start)
– The test also demonstrates functionality of the SC in hot and cold vacuum conditions
– Demonstrate structural integrity and workmanship of the spacecraft
– Provides experimental results for validating the thermal model
– Generate information on outgassing
● Thermal Vacuum Test are performed in a thermal vacuum chamber vibration capable
of producing the required temperature and vacuum levels required for the spacecraft.
– Test is scoped specifically based on the SC operational temperature ranges
– Test Methodology, setup, and limitations may be referenced from international
standards (ECSS space product assurance, MIL, ASTM or other.) Sential2A SC inside TVAC chamber at IABG, Germany Ref-https://www.flickr.com/photos/esa_events/16473881794/in/photostream/
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Environmental testing (Thermal Vacuum) (cont.)
● The thermal vacuum test is executed and planned by the AIT engineer and is supported by Thermal, subsystem
and systems engineer.
– Systems engineer supports AIT by specify the critical systems level test that needs to be validated at SC level
– Subsystem engineer provides support by identifying and notifying AIT of key areas of safety, functionality or
performance that they may have concerns about during TVT in their module/sub system test plan.
– The thermal engineer supports AIT by indicating the location of additional sensors or equipments that may be
required during the test.
– In addition, the thermal engineer also verifies the thermal model with TVAC testing results
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Environmental testing (Electromagnetic compatibility)
● EMC is usually performed last in EVT campaign, when the spacecraft is closest to flight configuration.
● The primary objective of EMC testing is to:
– Demonstrate and de-risk Electromagnetic compatibility with the launch vehicle and facility
– Demonstrate Electromagnetic self-compatibility under predefined operational scenarios
– Verify spacecraft antennas performance are as expected
● EMC Test are performed in an EMC chamber capable of absorbing noise levels at the required
testing frequencies for the spacecraft.
In addition the chamber must allow:
– The SC to exercise its RF systems with antenna
– SC must be isolated from external electromagnetic fields.
– Containment of emissions, preventing external user interference
Spacecraft is tested to acceptance levels based on the requirements
– Test is scoped based on the Launch vehicle Emission/Susceptibility mask
– Test Methodology, setup, and limitations may be referenced from international standards
(ECSS space product assurance, MIL, ASTM or others.)
Sentinal 1B SC inside Anechoic chamberRef-https://www.dlr.de/content/en/images/2016/2/microscope-in-an-emc-test-chamber
_22776.jpg?__blob=normal&v=9
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Environmental testing (Electromagnetic compatibility) (cont.)● The thermal vacuum test is executed and planned by the AIT engineer and is supported by an RF and an EMC engineer.
– The AIT engineer is responsible for SC operation and test setup flow down.
– AIT engineer works closely with EMC engineer to derive the test definition based on the launch agency mask.
– AIT supports RF engineer in defining the operational mode of the SC for self-susceptibility
● The main aspects of emc testing includes:
– Conducted emissions (CE) and susceptibility (CS)
• Not done at SC level as they are considered as a single system, usually tested in modules with high circuit complexity.
– Radiated emission (RE) and susceptibility (RS)
• Radiated emissions are measured to verify that the spacecraft emissions fall below the mask limits imposed by the launch agency for
both the launch vehicle and launch facility
• Radiated susceptibility is tested to verify that the spacecraft both survives and remains in a safe state when exposed to a predicted
emissions mask supplied by the launch agency covering the launch vehicle and launch facility
– Self susceptibility
• This test is done to verify that he spacecraft operating an integrated system in flight configuration, do not cause mutual interference to
its own system which may degrade its functionality or performance.
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Environmental testing (Mass property measurement)
● The Mass property measurement test is executed and planned by the Mechanical
engineer and is supported by AIT
– The AIT engineer is responsible for preparing the S/C to full flight configuration
prior to the test
– AIT engineer supports the mechanical team throughout the mass measurement
testing
● The main aspects of Mass property measurement includes :
– Spacecraft Mass
– Spacecraft center of gravity (C.o.G)
– Spacecraft moment of inertia (M.o.I) and product of inertia (P.o.I)
● The data gathered through Mass property measurement is used by the AOCS
engineer to optimize the spacecraft attitude estimation and control
● Mass properties measurements are also submitted to the launch agency as required
SC undergoing Mass property measurement
Reference- JAXA
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Environmental testing (System End to End test)
SEET
Environmental
Test campaign
EVT
VIB,TVAC,EMC
Spacecraft EVT & Testing
Systems level
Testing
Pack and ship
Spacecraft
Launch
campaign
TRR
FRR
Launch
65
Environmental testing (System End to End test) ● SEET is the last testing phase prior to launch, at this stage all ISFTs are expected to be complete
– In order to test the high level operation of the SC, a SEET test is generated by the systems engineer
– AIT supports the systems team throughout the test phase.
● SEET test can be broken down into two categories:
– Launch and early operations (LEOP) testing
– A day in the life of the spacecraft (Both minimum & flight representative scenarios)
● The SEET test validates the following:
– LEOP phase operations
– All spacecraft operating scenarios
– SC designed operating performance and generate an actual performance baseline of the spacecraft on the ground
● At the end of SEET, the EGSE configurations is validated and is considered to be a flight config which is passed onto the gro
und station.
– This includes the TT&C database along with any other ground station compatible software config files.
– LEOP scenarios will also be tested with the ground station systems using configs imported from the EGSE.
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AIT Documentation
• Dedicated documentation are generated throughout the AIT phase
– This is done to provide evidence of the verification process planning and progress.
• AIT documentation can be classified into multiple categories but are not limited to the following:
– Test plan
• Detailed timeline for each task during the test and identifies the required support personnel
– Test procedure
• Highlights the test objective, scope , test equipment setup, and GSE configuration along with Detailed step by
step procedure for conducting the test.
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AIT Documentation
– Test report
• Highlights the major outcome of the test and concludes the test based on the collected data and analysis.
– Configuration control
• Tracks the configuration of the SC and GSE used throughout the project phase.
– Operator and burn-in logs logs
• Operator logs are used to identify any task carried on the GSE or the assembled spacecraft. This allows tracking
of any changes or testing that may have been carried out along with the exact time when changes were made
to it.
• Whereas, Burn in logs are used to record burn-in time of the modules on the SC, this allows each module
operation to be monitored throughout the AIT phase.
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Test Tracking
• As mentioned earlier, Verification can take place at any point in the AIT phase. Hence, it is important to
track each verification point so that once a requirement has been verified, it can be recorded.
This is typically done using a test verification matrix (TVM)
• TVM also contains all test procedures any other reference documents required for testing.
– TVM at module level are generated by the module engineers and used from bench testing throughout the
project
– TVM are combined by AIT lead to form a project level TVM highlight all testing that needs to be verified at
AIT level up to launch.
– TVMs are fully customizable and can be developed based on test planning of a module/ spacecraft
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Thank you