General

JERG-2-330

DESIGN STANDARD
MECHANISMS

July 8, 2009

Japan Aerospace Exploration Agency

JERG-2-330

This is an English translation of JERG-2-330. Whenever there is anything ambiguous in thisdocument, the original document (the Japanese version) shall be used to clarify the intent of therequirement.

Disclaimer
The information contained herein is for general informational purposes only. JAXA makes nowarranty, express or implied, including as to the accuracy, usefulness or timeliness of any
information herein.
JAXA will not be liable for any losses relating to the use of the information.

Published by
Japan Aerospace Exploration Agency
Safety and Mission Assurance Department
2-1-1 Sengen Tsukuba-shi, Ibaraki 305-8505, Japani

JERG-2-330

Contents

1. Scope....................................................................................................................... 1
1.1 Purpose .............................................................................................................. 1
1.2 Scope of application ........................................................................................... 1
2. Related documents .................................................................................................. 1
2.1 Applicable documents ........................................................................................ 1
2.2 References ......................................................................................................... 1
3. Terminology, definitions and abbreviations .............................................................. 1
3.1 Terms and Definitions ......................................................................................... 1
3.2 Symbols and abbreviations................................................................................. 2
4. General requirements .............................................................................................. 2
4.1 System performance .......................................................................................... 2
4.2 Mission ............................................................................................................... 3
4.3 Function ............................................................................................................. 3
5. Design requirements ................................................................................................ 3
5.1 Interfaces ........................................................................................................... 3
5.2 Environmental design standard .......................................................................... 3
5.2.1
Ground environment ....................................................................................... 3
5.2.2
Launching environment ................................................................................... 3
5.2.3
Orbital environment......................................................................................... 4
5.3 Parts and materials............................................................................................. 4
5.3.1
Requirements for parts.................................................................................... 4
5.3.2
Requirements for materials ............................................................................. 4
5.4 Mechanism design.............................................................................................. 4
5.4.1
Accuracy control design .................................................................................. 5
5.4.2
Driving design ................................................................................................. 5
5.4.3
Operating life design ....................................................................................... 5
5.4.4
Tribology ......................................................................................................... 5
5.4.5
Not Used ......................................................................................................... 6
5.4.6
Other requirements ......................................................................................... 6
5.5 Structural design ................................................................................................ 7
5.5.1
General requirements related to structural design ........................................... 7
5.5.2
Allowable values of materials .......................................................................... 7
5.5.3
Strength safety margin .................................................................................... 7
5.5.4
Stiffness design............................................................................................... 7
5.6 Thermal design................................................................................................... 7
5.7 Electrical design ................................................................................................. 7
5.7.1
Electrical design .............................................................................................. 7
5.7.2
Electric wires ................................................................................................... 7
5.7.3
Electric connectors.......................................................................................... 8
5.7.4
Insulation ........................................................................................................ 85.7.5
Grounding ....................................................................................................... 8
5.7.6
Deformation of wiring ...................................................................................... 8
5.8 General requirements ......................................................................................... 8
5.8.1
Reliability ........................................................................................................ 8
5.8.2
Redundancy.................................................................................................... 8
5.8.3
Safety ............................................................................................................. 9
5.8.4
Operability....................................................................................................... 9
5.8.5
Maintainability ................................................................................................. 9
5.8.6
Interchangeability ............................................................................................ 9
5.8.7
Error proofing design ...................................................................................... 9
5.8.8
Other requirements ......................................................................................... 9ii

JERG-2-330

6. Verification ............................................................................................................. 10
6.1 Analytical verification .......................................................................................... 10
6.1.1
Identification of worst-case conditions ........................................................... 10
6.1.2
Thermal analysis ........................................................................................... 10
6.1.3
Structural analysis......................................................................................... 10
6.1.4
Function and performance analysis............................................................... 11
6.1.5
Analysis of dynamic margin........................................................................... 11
6.1.6
Occurrence of shock and sensitivity .............................................................. 11
6.1.7
Disturbance produced ................................................................................... 11
6.1.8
Lubrication analysis ...................................................................................... 11
6.1.9
Operating life analysis ................................................................................... 11
6.1.10 Magnetic or electromagnetic analysis ........................................................... 11
6.1.11 Radiation analysis ......................................................................................... 11
6.1.12 Stress analysis .............................................................................................. 12
6.2 Verification through testing ............................................................................... 12
6.2.1
Basic principle ............................................................................................... 12
6.2.2
Development test .......................................................................................... 12
6.2.3
Qualification tests.......................................................................................... 12
6.2.4
Acceptance test ............................................................................................ 13
6.2.5
Operating life test .......................................................................................... 14iii

JERG-2-330

1.

Scope
1.1 Purpose
This design standard describes the requirements for the design, quality control andtesting of mechanism assemblies (hereinafter referred to as "mechanisms") used inspacecraft (such as artificial satellites and probes) and aims to ensure a high reliability
in all the mechanisms with mechanical actuation.
1.2 Scope of application
The requirements to be handled in this design standard shall be applied to themechanisms installed in the spacecraft. In addition, the mechanism for rocket andmanned space equipment are not treated in this document.

2.

Related documents
2.1 Applicable documents
The following documents shall be applicable in the scope defined by this design
standard. If a contradiction arises, priority shall be given to this design standard unlessotherwise specified.
(1) JERG-2-000 Spacecraft (Artificial Satellite and Probe) Design Standard(2) ASTM E 595 Standard Test Method for Total Mass Loss and Collected Volatile
Condensable Materials from Outgassing in a Vacuum Environment(3) JERG-2-200 Electric Design Standard(4) JERG-2-310 Thermal Control System Design Standard(5) MIL-HDBK-5 Metallic Materials and Elements for Aerospace Vehicle Structures(6) JMR-001 System Safety Standard
2.2 References
The reference documents related to this design standard shall be as follows:(1) JERG-2-141 Space Environment Standard

3.

Terminology, definitions and abbreviations
3.1 Terms and Definitions(1) Mechanism
Assembly of machine elements connected mutually to accomplish relative motion;mechanism assembly(2) Outgassing
Emission of gas produced by material in a vacuum(3) Interface
Mechanically, thermally, electrically and operationally common boundary between
two elements in a system(4) Acceptance test
A test to verify that the systems, subsystems, components or function parts arecapable of satisfying the specifications defined in the purchase specification and the1

JERG-2-330

performance requirements specified in other documents and that the items are freefrom manufacturing defects(5) Contamination
Adhering of contaminants on the target surface or the state of adhesion(6) Lubrication
Use or application of a material with specific surface characteristics between two
surfaces in contact or in relative motion in order to reduce friction, wear oradhesion.
(7) Redundancy
Duplication of components or means for accomplishing specified functions. No
upper items will fail even if some parts fail.
(8) Debris
A French term meaning fragment. Refers to abrasion powders produced by theoperation of mechanism parts. Also refers to man-made dust and fragments driftingin space such as wreckage of man-made satellites.
(9) Total Ionizing Dose
Total dose of radiation absorbed in parts or materials up to a specific time(10) Tribology
Science and technology on two mutually interfering surfaces in relative motion andrelated problems and on-site application(11) Qualification test
A test to verify that the design of a mechanism or of mechanism parts is capable ofsatisfying the specified performance requirements under the operation environment
with the margin specified(12) Maintainability
A characteristic of design and facility of equipment for promoting checking, testing,inspection, service, repair and overhaul to accomplish the operational purposes withthe minimum time, expertise and resources under a specified maintenanceenvironment(13) Misalignment
Geometric position error between machine elements and parts (such astranslational displacement, inclination, torsion)(14) Mission
To achieve the purpose of the program by carrying out consistent investigation oroperation in space(15) Latching or locking
When no restrictions are imposed on one or more degrees of freedom of amechanism, latching or locking means to restrict such degree of freedom intentionally.
In such cases, some sort of operation must be performed to release the mechanism.
3.2 Symbols and abbreviations(1) EMC
4.

Electromagnetic compatibility

General requirements

The requirements shall be applied to the design and design verification of
mechanisms.
4.1 System performance
The functional performance of mechanisms shall comply with the performancerequirements of the system.

2

JERG-2-330

4.2 Mission
In designing a mechanism, the requirements shall be applied throughout the entire
period of the mission specified in individual programs. All the requirements andenvironment conditions in each phase of the mission shall be satisfied.
4.3 Function(1) Regulations on mechanism action shall be made.
(2) Regulations shall be made on the mechanical interface, action accuracy and speed
including tolerance. It shall be required to verify that the specified requirements are
satisfied.
(3) The action envelope area of mechanism components shall be specified. The
envelope area shall not interfere with other on-board equipment or spacecraft.
5.

Design requirements
5.1 Interfaces(1) Structural interfaces
Mechanisms shall conform to the structural interface conditions and requirements
defined in the specification.
(2) Thermal interfaces
Mechanisms shall conform to the thermal interface conditions and requirements
defined in the specification.
(3) Thermomechanical interfaces
Thermomechanical interfaces shall be designed in consideration of induced stress.
(4) Electric interfaces
Mechanisms shall conform to the electric interface conditions and requirements
defined in the specification.
(5) Physical interfaces
The mass of a mechanism shall conform to the requirements defined in thespecification.
(6) Other interfaces
Mechanisms shall conform to the interface conditions of optical (visual field),mounting alignment, accessibility during operation, envelope area, clearance withother equipment and ground-based equipment defined in the specification.
5.2 Environmental design standard
Mechanisms shall conform to the environmental condition requirements defined in
the specification.
5.2.1 Ground environment(1) Mechanisms shall satisfy the required performance even under ground handlingenvironment conditions such as ground test, assembly, storage and transportation.
(2) It shall be required to consider the ground test environment including temperature,vibration, sound, shock, different atmospheric gases, pressure, humidity,
cleanness and corrosive environment.
5.2.2 Launching environment

3

JERG-2-330(1) Mechanisms shall satisfy the required performance after being exposed torocket-launch environment conditions.
(2) As to the launching environment, changes in the parameters such as temperature,vibration, sound, shock, pressure and humidity shall be considered.
5.2.3 Orbital environment(1) Mechanisms shall satisfy the required performance under orbital environment
conditions until the end of their required operating life is reached.
(2) As to the orbital environment, such factors as vacuum, temperature cycle,
vibration, shock, radiation, ultraviolet and atomic oxygen shall be considered.
Consideration shall also be given to the effects of such space environment on thematerials used in the mechanism.
5.3 Parts and materials
It shall be required to select mechanical parts, materials and processes which
conform to the requirements for the functions, performance, environment conditions,
quality and reliability of the mechanism and other requirements defined in thespecification.
5.3.1 Requirements for parts(1) Mechanical parts shall be selected from certified parts or registered parts if
possible and proper.
(2) It shall be required to select mechanism components which conform to themechanism requirements(3) Mechanical parts shall be standardized to the possible and proper level.
5.3.2 Requirements for materials(1) It shall be required to select mechanism materials which conform to themechanisms requirements.
(2) In selecting metallic materials, consideration shall be given to corrosion resistance,
galvanic corrosion resistance, stress corrosion cracking, and as-needed surface
modification treatment in addition to physical and mechanical properties.
(3) In selecting mechanism materials which are to be exposed to the spaceenvironment, be sure that they have the tolerance to radiation, ultraviolet, atomic
oxygen and debris as well as the low outgassing characteristics which conform to
the applicable mission requirements.
(4) It shall be required to select materials for which change in characteristics due totemperature change and temperature cycle is within the required limit of themechanism(5) If environmental factors such as radiation, ultraviolet, atomic oxygen andtemperature environment may have a synergetic effect on the materials to be
selected, it is required that the effect on the materials under such complex
environment fall within the required limit of the mechanism.
(6) When using hygroscopic or swellable materials, it is required that the change inmaterial characteristics due to moisture absorption and swelling fall within therequired limit of the mechanism.
5.4 Mechanism design

4

JERG-2-330

This section specifies general design review items with respect to the mechanism
design such as parts and assemblies.
5.4.1 Accuracy control design
For mechanisms which require accuracy control, a proper error budget shall be
reviewed and designed for the following items.
(1) Machining and assembly tolerances, misalignment(2) Bending (deflection), torsion(3) Thermal deformation(4) Mechanical interference (movable envelope)(5) Frictional force and variation in frictional force, hysteresis(6) Variation in driving force (motor, spring, electromagnetic solenoid)(7) Control transient phenomena (resonance, overshoot)(8) Performance errors ascribable to other error variations
5.4.2 Driving design
A proper margin (allowance) shall be provided to mechanisms with a driven section.
Consideration shall be given to the following items:(1) For frictional forces, consideration shall be given to not only dynamic friction force
during steady drive but also to static friction force and hysteresis during activationand inverse driving.
(2) For motor driving, each motor shall have a torque (or force) margin which meetsthe requirements for expected changes in operational temperature and speed. The
driving current shall be in agreement with the power resource.
(3) In reviewing (calculating) the required driving force (drive resistance), it is required
to review the worst-case combination of operationally expected changes intemperature and speed with respect to each resistance element (such as bearing,gears, harness cables, latches and dampers). If necessary, the calculated values
shall be checked for validity through testing at the element and subassembly level.
(4) For drive mechanism elements using a redundant system, a proper torque (orforce) margin shall be ensured in case an element fails under the worst-caseconditions.
(5) For deteriorated drive mechanism elements with a redundant system, the marginof other mechanism elements shall be evaluated in consideration of the possibility
that the deteriorated mechanism will develop resistance force.
5.4.3 Operating life design
The operating life of a mechanism shall correspond to the expected sum total of
nominal ground test and orbital operation. It is required that the mechanism bedesigned so that it can reach the required operating life under the proper environment
conditions.
5.4.4 Tribology(1) In designing a mechanism, it is required that the mechanism conform to its
performance requirements and that the sliding and rolling surfaces be properly
lubricated to prevent adheasion and reduce wear over the entire duration of therequired operating life.

5

JERG-2-330(2) Requirements on the storage, handling and operation of the mechanism shall beclarified in order to maintain the soundness of the lubricating surfaces of themechanism.
(3) The rate of outgassing in the lubricant used to lubricate the mechanism shall bemeasured in accordance with a predetermined measurement method. (See ASTM
E 595 Standard Test Methods for Total Mass Loss and Collected Volatile
Condensable Materials from Outgassing in a Vacuum Environment.)
5.4.5 Not Used
5.4.6 Other requirements
5.4.6.1 Replaceable mechanism(1) It is desirable that replaceable mechanisms be designed with error proofing toensure installation in the correct direction.
(2) Mechanisms using a crash damper shall be designed to be assembled only in thecorrect direction.
5.4.6.2 Latching or locking
It is required that latching mechanisms for locking be designed properly to prevent
accidental release caused by vibration or shock generated during mission
implementation.
5.4.6.3 End stops
In order to drive the operation items properly and prevent interference with theinterface equipment, a mechanism in which movement or rotation is restricted shall be
provided with a normal or emergency mechanical end fastener which regulates themechanism's ultimate motion or movement to the maximum position.
5.4.6.4 Separable contact surface
The adhesion force between contact surfaces in which separation is likely to occur
shall be smaller than the specified value.
Contact surfaces in the joint shall be designed considering the contact conditions,material characteristics and surface roughness.
5.4.6.5 Venting(1) It shall be required to design a proper means for venting during launching andorbital operation unless the mechanism is air-tight or designed to deal with theforming of internal pressure in terms of function and performance.
(2) The venting method shall be designed properly to minimize the contamination of
bearing, optical equipment and other high-sensitive equipment.
(3) For ventilation outside the lubricated portions, the lubricant shall conform to thecontamination requirements for other applicable spacecraft materials.
5.4.6.6 Resetting and locking devices using explosive devices or other actuators
The operation of a releasing device shall conform to the cleanness requirements.

6

JERG-2-330

The releasing device shall be designed with a proper method for trapping debris.
5.5 Structural design
5.5.1 General requirements related to structural design
The structural design of a mechanism shall conform to the requirements.
Mechanisms shall be provided with the required functions and performance underthe expected thermal environment conditions throughout their entire operating life.
Transitional conditions shall be included in the thermal environment conditions.
5.5.2 Allowable values of materials(1) The permissible design standard for structure is generally specified in
MIL-HDBK-5 Metallic Materials and Elements for Aerospace Vehicle Structures.
(2) If the required design strength or other mechanical, physical or thermal reliabilities
are not proper, it is required to make a new specification and perform evaluation or
testing for assurance.
5.5.3 Strength safety margin(1) Mechanisms shall satisfy the mechanical interface and performance requirements
and withstand the expected environment during handling, transportation, test,
storage, launching and orbital operating life without damage or deterioration.
(2) Mechanisms shall have a positive safety margin for all environments.
5.5.4 Stiffness design
If there are requirements for natural frequency to correspond to the machine
environment during launching or requirements for ensuring orbital flexible structure
characteristics, the mechanism shall be designed with rigidity to meet therequirements.
5.6 Thermal design
The thermal design of a mechanism shall conform to the requirements specified in
JERG-2-310 Thermal Control System Design Standard. Mechanisms shall meet thefollowing requirements.
Mechanisms shall be provided with the required functions and performance underthe expected thermal environment conditions throughout their entire operating life.
Transitional conditions shall be included in the thermal environment conditions.
5.7 Electrical design
5.7.1 Electrical design
Mechanisms shall be designed to meet the requirements for electrical performanceand have stable electrical characteristics throughout their operating life cycle. Basically,
JERG-2-200 Electric Design Standard.
5.7.2 Electric wires(1) Fixed parts shall be used for portions which are likely to be affected by bending.
(2) Cables and electric wires shall be formed, arranged and supported considering the7

JERG-2-330

following items:(a) No electric wires, electric wire terminals or connectors shall be subject tomechanical stress exceeding their tolerance.
(b) Wiring shall be carried out at a distance from sharp edges or liquid pipe lines.
(c) In a vibration environment, damages and failures shall be prevented.
5.7.3 Electric connectors
Connector types and shapes (example: number of pins) shall be selected so as to
avoid damage or coupling errors.
5.7.4 Insulation
The insulation of electric wires shall be designed in accordance with JERG-2-200
Electric Design Standard.
5.7.5 Grounding
Mechanisms shall be grounded at a mechanical interface point. Any components
insulated from mechanical interface points shall be ground separately as needed.
5.7.6 Deformation of wiring
For electric wires which deform at movable portions, consideration shall be given to
make shape change and reaction force repeatable.
5.8 General requirements
5.8.1 Reliability(1) Mechanisms are an important component which can become a single point of
failure in many cases. Due consideration shall be given to their reliability.
(2) The reliability of mechanisms can be increased by providing a large design margin
or designing single points of failure with redundancy.
(3) For mechanisms that are indispensable to the success of mission, it is required toprove that the required reliability is satisfied through analysis or testing.
(4) For parts with a limited operating life, the operating life shall be verified throughtesting or analysis.
(5) It is required that the failure of a part will not cause nonconformance in otherequipment or mechanisms.
(6) Reliability analysis shall be performed in accordance with JMR-004 Reliability
Program Standard.
5.8.2 Redundancy(1) All single points of failure in the mechanism shall be identified in the design phase.
To minimize the number of single points of failure and satisfy the reliability
requirements, the mechanism shall be designed with a redundant configuration
where possible.
(2) If the entire mechanism cannot be designed with a redundant configuration,
redundancy shall be accomplished at the mechanism component level.
(3) It is required that a failure in one subcomponent in the redundant system will notcause nonconformance in other functions or parts in the redundant system.

8

JERG-2-330

5.8.3 Safety(1) In designing a mechanism, due consideration shall be given to safety so as toprevent harm to personnel and peripheral equipment in all phases including
manufacturing, assembly, testing and transportation. Due consideration shall begiven to prevent damage to the mechanism in all the phases.
(2) Safety design shall be performed in accordance with JMR-001 System Safety
Standard.

5.8.4 Operability(1) It is required that no operational restrictions are imposed on the mission indesigning a mechanism. If imposing operational restrictions is inevitable, theconditions shall be identified.
(2) When off-nominal requirements are made from the system, it is required that aworst-case analysis be performed in the design phase considering off-nominal
operation and that the system design be supported to minimize the sensitivity ofdesign and operational performance to the changes in parameters.
5.8.5 Maintainability(1) It is required that mechanisms be maintenance-free during storage or ground
operation. If maintenance must be performed by necessity during storage or at theend of the ground operating life, it is required to record the number of actions,nonconformance identification and repair details, and thereby indicate theappropriateness of maintenance.
(2) Mechanisms shall be designed considering the replacement of critical parts if
appropriate.
5.8.6 Interchangeability
It is required that mechanisms and parts be designed considering interchangeability
where possible.
5.8.7 Error proofing design(1) It is required that mechanisms and parts be designed so as to prevent improper
assembly.
(2) Mechanisms and parts shall be designed so that testing and inspections can be
performed to check for proper assembly and mounting.
5.8.8 Other requirements
5.8.8.1 Identification nameplate(1) Mechanisms and parts shall be identified by nameplates. Nameplates shall be
attached to an outer surface so that no mechanism functions will be affected.
(2) Pasting, etching or direct display with regard to the article may be performed if
there are no appropriate outer surfaces to which to attach a nameplate.
5.8.8.2 Non-flight display

9

JERG-2-330

Non-flight articles shall be distinguished from flight articles.
5.8.8.3 Measurement item
(1) It is required that mechanisms be designed so that important data which canensure its performance and identify failures will be measured continually from theground evaluation phase to orbital operation.
(2) Measurement data shall be obtained through a telemeter wherever possible.
6.

Verification(1) The development of a space mechanism shall include a verification process.
Verification requirements shall be divided into analytical verification requirements andtest verification requirements.
(2) A verification matrix shall be created.
6.1 Analytical verification
Analytical verification of mechanisms shall include the following items:(1) Identification of the worst operational and non-operational cases through thermal
analysis(2) Structural analysis stiffness, stress caused by mechanical/thermal load, andfatigue)(3) Performance analysis of operable functions under every applicable environmentand operation condition (based on the worst-case conditions identified) in order toderive the load, time, shock, speed, dimensional stability and position accuracy.
(4) Dynamic margin(5) Occurrence of shock and sensitivity(6) Occurrence of external disturbance and sensitivity(7) Lubrication analysis(8) Operating life analysis(9) Magnetic or electromagnetic analysis(10) Radiation analysis(11) Stress analysis
6.1.1 Identification of worst-case conditions
The operational and non-operational conditions under the mechanism worst-caseconditions shall be set in accordance with the environment, load, functional
performance of specific spacecraft and mechanisms.
6.1.2 Thermal analysis
Thermal analysis of mechanisms shall conform to the requirements specified in
JERG-2-310 Thermal Control System Design Standard.
6.1.3 Structural analysis
Structural analysis of mechanisms shall conform to the requirements specified in
JERG-2-320 Structure Design Standard.

10

JERG-2-330

6.1.4 Function and performance analysis
The requirements for function models shall be as follows:(1) The analysis models or numerical models to be used as the basis for analysis shallhave flight hardware mechanism interface conditions and spacecraft
characteristics with respect to the following items:(a) Mass(b) Inertial force(c) Position of center of gravity(d) Structural stiffness(e) Application force or application torque(f) Resistant force(2) The following items shall be performed on the model shown in Section (1).
(a) Parametric study of mechanical variation factors(b) The analysis model shall be renewed through the design and test phases ifnecessary.
The analysis results shall be verified in comparison with the related test results.
6.1.5 Analysis of dynamic margin
It shall be required to verify through analysis that mechanisms conform to thespecified requirements related to the dynamic margin.
6.1.6 Occurrence of shock and sensitivity
It shall be required to verify through analysis that mechanisms conform to therequirements related to the occurrence of shock and sensitivity specified in themechanism requirement specification.
6.1.7 Disturbance produced
It shall be required to verify through analysis that the operation of mechanisms
conforms to the vibration-related (micro-vibration) requirements defined in themechanism requirement specification.
6.1.8 Lubrication analysis(1) It shall be required to verify that the selected lubrication system conforms to theapplication method or operating life.
(2) The quantity of lubricant shall be evaluated for conformity through analysis.
6.1.9 Operating life analysis(1) Mechanisms with a limited operating life shall be identified.
(2) It shall be required to verify through analysis that mechanisms with a limited
operating life conform to the operating life requirements.
6.1.10 Magnetic or electromagnetic analysis
It shall be required to verify through analysis that the EMC standard is satisfied.
6.1.11 Radiation analysis

11

JERG-2-330

It shall be required to perform analysis on radiation-sensitive mechanisms for total
ionizing dose and verify that the mechanisms conform to the performancerequirements including operating life.

6.1.12 Stress analysis
It shall be required to perform stress analysis on electric parts (including harnesses)
to verify that the electric parts conform to the derating standard.
6.2 Verification through testing
6.2.1 Basic principle(1) In testing, it shall be required that the hardware conform to the requirements
related to design, manufacturing and performance. Testing includes development
tests, qualification tests, acceptance tests and operating life tests.
(2) The mechanism design shall conform to the ground operation under atmosphericenvironment conditions and thermal vacuum conditions. Restrictions on operation
under allowable operations and environment conditions shall be defined.
(3) The mechanism design shall be performed with consideration given to conducting
typical ground tests in an operable form. It shall be required that the mechanism
design conforms to testing under the atmospheric environment and thermal
vacuum environment conditions under gravity.
6.2.2 Development test
(1) A development test shall be planned and conducted as follows:(a) Input necessary to design and analysis (dynamic analysis in particular) shall be
provide.
(b) New designs shall be verified.
(c) Verification shall be made on critical mechanisms.
(2) Testing
Unless clearly verified based on the test data obtained from the past space
application cases, the following verification tests shall be conducted on themechanisms of the engineering model in the initial phase of the project.
(a) Function and performance test(b) Vibration test and shock test (if necessary as verification of new design)(c) Thermal vacuum test or temperature test (if necessary as verification of new
design)(d) Operating life test on mechanism elements with a critical operating life
(3) Critical mechanisms and parts which require a development test shall be identified
in the initial phase of the design and development program.
6.2.3 Qualification tests
Mechanisms shall be qualified through testing.
Qualification tests shall be conducted according to typical procedures under a typicalenvironment.
6.2.3.1 Structure test
In a structure test, verification shall be made in accordance with the structure-related

12

JERG-2-330

requirements specified in JERG-2-320 Structure Design Standard.
6.2.3.2 Thermal vacuum test
In a thermal vacuum test, verification shall be made in accordance with therequirements specified in JERG-2-310 Thermal Control System Design Standard.
6.2.3.3 Functional test
In a functional test, it shall be required to verify that the mechanisms conform to thefunction and performance requirements even after being exposed to the environment
conditions (load and heat) of qualification test.
Mechanical and thermal stabilization shall be performed before conducting a test.
6.2.3.4 EMC test
When using an EMC-sensitive component with regard to the mechanism or whenspacecraft-specific EMC requirements are imposed on the mechanism, it shall be
required to verify the EMC performance of the mechanism.
6.2.3.5 Electrical test
In an electrical test, it shall be required to verify that the mechanism conforms to theelectrical function and performance requirements.
6.2.4 Acceptance test
For products newly assembled based on the qualified design, it shall be required toverify through an acceptance test that the manufactured hardware is free frommanufacturing errors. Acceptance tests shall be conducted at a level higher than the
expected level at the time of launching but lower than the qualification level. Testing
shall be conducted at a level which causes no damage to the hardware. No repair or
adjustment after the acceptance test shall be necessary.
6.2.4.1 Test items
It is desirable that testing include the following items as well as the detection ofworkmanship errors.
The functions and performance shall satisfy the requirements.
It shall be verified that the electric wiring can withstand the required voltage withoutcausing destructive discharge.
6.2.4.2 Running-in
It is desirable that running-in be performed on mechanisms unless it is harmful interms of performance and can decrease the reliability.
6.2.4.3 Inspection
The dimensions, mass, appearance and identification marking of the machine shallbe inspected properly after the acceptance test.

13

JERG-2-330

6.2.5 Operating life test
6.2.5.1 Operating life qualification
After going through an environment test at a level higher than that of the acceptancetest, the design, operating life and performance of mechanisms shall be verified forconformity under the operating life test conditions simulating the ground and in-orbit
environment conditions.
6.2.5.2 Requirements for operating life test conditions
The operating life test conditions shall properly represent the following parameterswhich impact the operating life.
(1) Thermal conditions, load conditions and motion profiles properly corresponding tooperational conditions.
(2) When conducting an accelerated operating life test to verify the operating life
performance of a mechanism, the conditions of the accelerated operating life test
shall represent the worst-case environment in terms of deterioration.
6.2.5.3 Acceptance criterion of operating life test
In an operating life test, the functional performance of mechanisms shall conform to
the design requirements after the test is finished.

14