FINAL_SOW_6.8.2016.pdf

Attachment 1 Page i of 89

NAVAL RESEARCH LABORATORY

4555 Overlook Avenue, S.W.

Washington, DC 20375-5000

NAVAL CENTER

FOR

SPACE TECHNOLOGY

Thermal Vacuum Compatible Gravity Offloader Statement of Work for the

Naval Center for Space Technology

NCST-S-GN001 Rev. B 10 May 2016

NCST-S-GN001 Rev. B Page ii of 89 ii

RECORD OF CHANGES

REVISION

LETTER

DATE TITLE OR BRIEF DESCRIPTION

– 2 March 2016 Released via ERN #GN003 A 5 April 2016 Revised via CCN #NCST-S-GN001-001 B 10 May 2016 Revised via CCN #NCST-S-GN001-002

NCST-S-GN001 Rev. B Page iii of 89 iii

TBX ITEMS

Number Section TBx Due Date

TBR-1 3.6.7

GO-103 Telemetry shall be reported in a (TBR-1) format to be negotiated between the supplier and NRL.

PDR - 2

months

NCST-S-GN001 Rev. B Page iv of 89 iv

TABLE OF CONTENTS

Section Title Page

1.0 INTRODUCTION .......................................................................................................................................... 1-1

1.1 Purpose ............................................................................................................................................................. 1-1

1.2 Scope ................................................................................................................................................................ 1-1

1.3 Precedence and Criticality of Requirements .................................................................................................... 1-1

1.4 Requirement Format ......................................................................................................................................... 1-2

1.5 Definitions ........................................................................................................................................................ 1-2

2.0 APPLICABLE DOCUMENTS ..................................................................................................................... 2-1

2.1 Government Documents ................................................................................................................................... 2-1

2.1.1 Specifications (Federal, Military, and Other) ................................................................................................ 2-1

2.1.2 Handbooks and Standards (Federal, Military, and Other) ............................................................................. 2-1

2.1.3 Program Documents ...................................................................................................................................... 2-1

2.1.4 Drawings (Appendix C) ................................................................................................................................ 2-1

2.1.5 Other Publications ......................................................................................................................................... 2-1

2.2 Non-Government Documents ........................................................................................................................... 2-2

2.2.1 Specifications and Standards ......................................................................................................................... 2-2

2.2.2 Drawings ....................................................................................................................................................... 2-2

2.2.3 Other Publications ......................................................................................................................................... 2-2

3.0 REQUIREMENTS ......................................................................................................................................... 3-1

3.1 Mechanical ....................................................................................................................................................... 3-2

3.1.1 Thermal Vacuum Chamber Interfaces ........................................................................................................... 3-2

3.1.2 Laboratory Interfaces .................................................................................................................................... 3-2

3.1.3 Mass .............................................................................................................................................................. 3-3

3.1.4 Design Loads ................................................................................................................................................. 3-3

3.1.5 Assembly and Installation ............................................................................................................................. 3-3

3.2 Electrical .......................................................................................................................................................... 3-4

3.2.1 Power ............................................................................................................................................................ 3-4

3.2.2 Data ............................................................................................................................................................... 3-5

3.2.3 Parts ............................................................................................................................................................... 3-5

3.2.4 Harness and Wiring ....................................................................................................................................... 3-5

3.2.5 General .......................................................................................................................................................... 3-6

3.3 Software ........................................................................................................................................................... 3-6

3.3.1 Documentation .............................................................................................................................................. 3-6

3.3.2 Configuration/Version Control ...................................................................................................................... 3-6

3.3.3 Software Load ............................................................................................................................................... 3-6

3.4 Materials and Processing .................................................................................................................................. 3-6

3.5 Environment ..................................................................................................................................................... 3-8

3.5.1 Temperature .................................................................................................................................................. 3-8

3.5.2 Pressure ......................................................................................................................................................... 3-8

3.6 Operational ....................................................................................................................................................... 3-9

3.6.1 Payload Capacity ........................................................................................................................................... 3-9

3.6.2 Payload Mass Change ................................................................................................................................... 3-9

3.6.3 Offloading Accuracy ................................................................................................................................... 3-11

3.6.4 Envelope ...................................................................................................................................................... 3-12

3.6.5 Offloading Motion ....................................................................................................................................... 3-13

3.6.6 Controls ....................................................................................................................................................... 3-17

3.6.7 Telemetry .................................................................................................................................................... 3-18

3.6.8 Safety .......................................................................................................................................................... 3-19

3.6.9 Maintenance ................................................................................................................................................ 3-20

3.7 Documentation ............................................................................................................................................... 3-20

3.8 Technical Reviews ......................................................................................................................................... 3-22

3.8.1 Review Contents ......................................................................................................................................... 3-22

3.8.2 Review Actions and Minutes ...................................................................................................................... 3-23

NCST-S-GN001 Rev. B Page v of 89 v

3.8.3 Review Descriptions ................................................................................................................................... 3-24

3.8.3.1 System Requirements Review and Kickoff Meeting ................................................................................ 3-24

3.8.3.2 Preliminary Design Review ...................................................................................................................... 3-24

3.8.3.3 Critical Design Review ............................................................................................................................ 3-24

3.8.3.4 Post Ambient Test Pre-Shipment Review & Acceptance Test Readiness Review ................................... 3-25

3.8.3.5 Post Acceptance Test Buyoff Review ...................................................................................................... 3-25

3.8.3.6 Status Reviews ......................................................................................................................................... 3-25

4.0 PERFORMANCE VERIFICATION AND PRODUCT ASSURANCE .................................................... 4-1

4.1 Quality Management System ........................................................................................................................... 4-1

4.1.1 Procuring Activity Quality Assurance Oversight .......................................................................................... 4-1

4.1.2 Quality Assurance Records ........................................................................................................................... 4-2

4.1.2.1 Quality Assurance Data .............................................................................................................................. 4-2

4.1.2.2 Reserved ..................................................................................................................................................... 4-2

4.2 Nonconformance and Failure Reporting .......................................................................................................... 4-2

4.3 Configuration Control ...................................................................................................................................... 4-2

4.4 Data Types ....................................................................................................................................................... 4-2

4.4.1 Data Format ................................................................................................................................................... 4-2

4.4.2 Right of Access ............................................................................................................................................. 4-2

4.4.3 Problem Reporting ........................................................................................................................................ 4-2

4.5 Verification ...................................................................................................................................................... 4-2

4.5.1 Responsibility for Tests ................................................................................................................................. 4-2

4.5.2 Notification of Tests ...................................................................................................................................... 4-2

4.6 Analysis ............................................................................................................................................................ 4-3

4.6.1 Structural Analysis ........................................................................................................................................ 4-3

4.6.2 Failure Mode, Effects, and Criticality Analysis ............................................................................................ 4-4

4.6.3 Thermal Analysis .......................................................................................................................................... 4-4

4.7 Testing .............................................................................................................................................................. 4-4

4.7.1 Acceptance Testing ....................................................................................................................................... 4-4

4.7.2 Thermal Vacuum Testing .............................................................................................................................. 4-5

5.0 REQUIREMENTS FOR CONTRACT OPTIONS ..................................................................................... 5-1

5.1.1 Option 1 ......................................................................................................................................................... 5-1

5.1.2 Option 2 ......................................................................................................................................................... 5-1

5.1.3 Option 3 ......................................................................................................................................................... 5-1

5.1.4 Option 4 ......................................................................................................................................................... 5-1

5.1.5 Option 5 ......................................................................................................................................................... 5-1

5.1.6 Option 6 ......................................................................................................................................................... 5-1

5.1.7 Option 7 ......................................................................................................................................................... 5-1

5.1.8 Options 10, 11, and 12 .................................................................................................................................. 5-2

5.1.9 Option 13 ....................................................................................................................................................... 5-2

6.0 SCHEDULE AND DELIVERABLES .......................................................................................................... 6-1

6.1 Deliverables ...................................................................................................................................................... 6-1

6.1.1 Hardware ....................................................................................................................................................... 6-1

6.1.2 Documentation .............................................................................................................................................. 6-1

6.1.3 Reviews ......................................................................................................................................................... 6-1

6.2 Schedule ........................................................................................................................................................... 6-1

7.0 CONTRACT DATA REQUIREMENTS LIST ........................................................................................... 7-1

7.1 CDRL Summary ............................................................................................................................................... 7-1

8.0 CUSTOMER COMMUNICATION ............................................................................................................. 8-1

8.1 Contract Communications ................................................................................................................................ 8-1

8.2 Technical Communications .............................................................................................................................. 8-1

9.0 NOTES ............................................................................................................................................................ 9-1

9.1 Acronyms and Abbreviations ........................................................................................................................... 9-1

NCST-S-GN001 Rev. B Page vi of 89 vi

APPENDIX A VERIFICATION ......................................................................................................................... A-1 A.1 Verification Methods ....................................................................................................................................... A-1 A.1.1 Analysis (A) ................................................................................................................................................. A-1 A.1.2 Inspection (I) ................................................................................................................................................ A-1 A.1.3 Demonstration (D) ....................................................................................................................................... A-1 A.1.4 Test (T) ......................................................................................................................................................... A-1 A.2 Verification Matrix .......................................................................................................................................... A-1

APPENDIX B OFFLOADING TRAJECTORY TIME HISTORIES ............................................................... B-1

APPENDIX C INTERFACE CONTROL DRAWINGS ................................................................................... C-1

NCST-S-GN001 Rev. B Page vii of 89 vii

LIST OF FIGURES

Section Title Page

Figure 1-1. Gravity Offloader System Configuration for Use in TVAC Chamber .................................................... 1-2 Figure 1-2. Gravity Offloader System Configuration for Use on Laboratory Floor .................................................. 1-3 Figure 1-3. Gravity Offloader Lift Point ................................................................................................................... 1-3 Figure 1-4. Robotic Arm in Thermal Vacuum Chamber ........................................................................................... 1-4 Figure 1-5. Cleanroom and Thermal Vacuum Chamber with Door Open during Satellite Integration (Air Barge in Front of Chamber) ..................................................................................................................................................... 1-5 Figure 1-6. Thermal Vacuum Chamber Interior During Satellite Integration ........................................................... 1-5 Figure 3-1. Mass Change: Overall Offloaded Mass between 10 – 50 kg ............................................................... 3-10 Figure 3-2. Mass Change: | Mass Before – Mass After | ≤ 25 kg .......................................................................... 3-10 Figure 3-3. Offset and Noise Errors......................................................................................................................... 3-11 Figure 3-4. Robot Lab Height Restrictions .............................................................................................................. 3-13 Figure 3-5. Offloader Vertical Range of Motion ..................................................................................................... 3-14 Figure 4-1. Gravity Offloader Thermal Vacuum Test Profile ................................................................................... 4-6

NCST-S-GN001 Rev. B Page viii of 89 viii

LIST OF TABLES

Section Title Page

Table 3-1. Gravity Offloader Key Performance Parameters ...................................................................................... 3-1 Table 3-2. Offloading Accuracy Requirements ....................................................................................................... 3-11 Table 3-3. Offloading Accuracy (GOAL) ............................................................................................................... 3-12 Table 3-4. Offloading Trajectories .......................................................................................................................... 3-15 Table 3-5. EIDP Contents ........................................................................................................................................ 3-21 Table 3-6. Review Data Package Summary ............................................................................................................ 3-22 Table 4-1. Gravity Offloader Thermal Vacuum Test Temperatures .......................................................................... 4-6 Table 6-1. Gravity Offloader Delivery Schedule ....................................................................................................... 6-1 Table 7-1. CDRL Summary ....................................................................................................................................... 7-1 Table A-1. Gravity Offloader Requirement Verification Matrix .............................................................................. A-1

NCST-S-GN001 Rev. B Page 1-1 of 89

1-1

1.0 INTRODUCTION

This Statement of Work (SOW) establishes the design, development, test, and performance requirements for the Thermal Vacuum (TVAC) compatible, robotic arm system gravity offloader being developed for the U.S. Naval Research Laboratory’s (NRL) Naval Center for Space Technology (NCST).

1.1 Purpose

It is critical to exercise as much of the actual range of performance of a robotic arm system as possible during ground testing in order to reduce the risk of an on-orbit failure. However, in order to minimize mass and power many flight robotic arm systems are designed and optimized for the micro-gravity environment of space. As a result they often cannot operate fully or at all in a 1g environment. This can severely limit, or even eliminate the amount of ground testing that can be performed in order to reduce the risk of on-orbit failure.

Gravity offloading systems can be used to vastly increase the amount of ground testing that can be performed. This enables the development and verification of arm motion sequences required to perform various on-orbit tasks. A gravity offloader can also allow for an accurate measurement of the power draw from the joint motors for thermal design validation. These gravity offloading systems typically consist of a structure that supports moving offload lift points. The offload lift points attach to the robotic arm system to counteract its weight as well as the weight of the payload, enabling the arm to operate on Earth a simulated zero gravity environment.

The specified gravity offloading system will enable ground testing for a wide array of robotic arm systems, from

0.76 meters (30 inches) long arms that can only lift 0.1 kg (0.22 lbm) payloads to arms that are 2.5 meters (100 inches) long and can support 200 kg (441 lbm) payloads. The specified gravity offloader has one offload lift point in the baseline design, which provides flexibility for various robotic arm types and configurations. Furthermore, the gravity offloader should be able to accommodate up to four total offload lift points at some time in the future. A key aspect of the gravity offloader is that it is thermal vacuum compatible, and is designed to maximize the potential range of motion within NCST's largest thermal vacuum chamber. The working envelope of this thermal vacuum chamber is a horizontal cylinder 4.88 meters (16 feet) in diameter by 9.14 meters (30 feet) long. This will enable NCST to validate the robotic arm systems’ thermal design, and to quantify critical robotic phenomena such as stiction, various arm dynamics, software control algorithms, and lubricant performance that are influenced by the space environment, and can only be accurately measured in a thermal vacuum environment where the arm is gravity offloaded. The gravity offloader will support testing operations in the thermal vacuum chamber and the ambient pressure and temperature Robot Lab high bay. This offloading system will enable a significant amount of robotic arm risk reduction ground testing that is currently not possible at NRL.

1.2 Scope

This SOW defines the requirements for the design, fabrication, test, and delivery of the gravity offloader system and its associated documentation in accordance with this SOW. The supplier is responsible for meeting the requirements of this SOW, the contract, the drawings, and the Contract Data Requirements Lists (CDRL).

1.3 Precedence and Criticality of Requirements

The requirements stated in this specification are not of equal importance or weight. The following three paragraphs define the weighting factors incorporated in this specification.

a. “Shall” designates mandatory requirements. Any deviations from these contractually imposed mandatory requirements require the approval of the procuring activity.

b. “Should” designates “requirements” which are requested, but are not mandatory. Unless required by other contract provisions, noncompliance with the should paragraphs does not require approval of the contracting officer, but does require technical substantiation.

c. “Will” or “may” designate the lowest weighting level. The will or may “requirements” designate intent and are often stated as examples of acceptable designs, items, and practices. Unless required by other contract provisions, noncompliance with the will or may paragraphs does not require approval of the contracting officer and does not require documented technical substantiation.

In this document, those paragraphs which are intended for information or clarification, but do not represent requirements, appear below a requirement. “Will” is used often in these notes to express expectations of performance. Following such introductory text, it is possible that the same basic information may exist as a

NCST-S-GN001 Rev. B Page 1-2 of 89

1-2 requirement, but it will be properly numbered as a requirement. For convenience and tracking, all requirement statements other than notes, figures, and tables are assigned requirement identifiers.

A few requirements have both “threshold” and “goal” values assigned. For these requirements, the contractually required value is the “threshold” value, while the “goal” value is provided to communicate the desire to achieve above and beyond the threshold value when this doesn’t significantly increase cost or complexity.

1.4 Requirement Format

The mandatory “shall” requirements in this document are formatted as follows:

GO-XXX: This is the requirement Identification (ID) number. The digits “XXX” constitute the requirement number.

These numbers are not sequential and some numbers are skipped, but they are not repeated. After the requirement ID comes the requirement text containing the “shall” statement.

1.5 Definitions

The gravity offloader systems consists of two major subsystems, the gravity offloader assembly (or gravity offloader) and the control system. The gravity offloader assembly includes all hardware installed inside, outside, and attached to the thermal vacuum chamber pressure vessel including the harnesses, any fluid tubing, and all of the thermal vacuum chamber port plates. It also includes any additional support legs and adapter structures required to interface to the T-slot floor or to be configured for use in a laboratory environment. The control system includes the control computer, computer monitor, rack mounted electronic equipment, any fluid equipment, and all harnesses and any fluid tubing between these pieces of equipment and the port plates.

For the purpose of this document, a “test configuration” is defined as a Unit Under Test (UUT) offloaded by an offload lift point at a location on the UUT. A change in test configuration is defined as any change that requires physical access to the offloader hardware or the UUT that is located in a TVAC chamber. Examples include:

Removing an offload lift line from one point on the UUT and reattaching it to a second point on the UUT

Removing a 3 meter long Robot Arm UUT, and replacing it with a 1 meter long Robot Arm UUT

Adding, removing, or replacing hardware that the UUT would interface with and/or manipulate

Figure 1-1 and Figure 1-2 respectively, show the gravity offloader system configuration for use in the TVAC chamber and for use in ambient temperature and pressure on the laboratory floor along with a UUT.

Figure 1-1. Gravity Offloader System Configuration for Use in TVAC Chamber

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1-3

Figure 1-2. Gravity Offloader System Configuration for Use on Laboratory Floor

Figure 1-3 shows the gravity offloader lift point (vendor hardware) and lift fixture (NRL hardware).

Figure 1-3. Gravity Offloader Lift Point

Figure 1-4, Figure 1-5, and Figure 1-6, respectively, show a robotic arm in NRL’s large thermal vacuum chamber, satellite integration into the thermal vacuum chamber as seen from the clean room, and a view from inside the thermal vacuum chamber looking out during satellite integration.

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1-4

Figure 1-4. Robotic Arm in Thermal Vacuum Chamber

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1-5

Figure 1-5. Cleanroom and Thermal Vacuum Chamber with Door Open during Satellite Integration (Air Barge in Front of Chamber)

Figure 1-6. Thermal Vacuum Chamber Interior During Satellite Integration

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2.0 APPLICABLE DOCUMENTS

2.1 Government Documents

The following documents of the exact issue shown form a part of this document solely to the extent specified herein.

In the event of conflict between the documents referenced herein and the contents of this document, the contents of this document shall be considered a superseding requirement. Equivalent in-house procedures or specifications replacing military specification are acceptable if approved by the procuring activity. Copies of Military and Federal specifications, standards, drawings, handbooks, and publications are available in the official Department of Defense (DoD) repository, the ASSIST database (see quicksearch.dla.mil). Other documents should be obtained from the procuring activity or as directed by the contracting officer.

2.1.1 Specifications (Federal, Military, and Other)

Number Title

2.1.2 Handbooks and Standards (Federal, Military, and Other)

FED-STD-209E Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones

MIL-STD-889 Dissimilar Metals

MIL-STD-1629 Procedures for Performing A Failure Mode, Effects, and Criticality Analysis

NASA Reference Publication 1124

Outgassing Data for Selecting Spacecraft Materials Online (available at http://outgassing.nasa.gov/)

SP-R-0022A Vacuum Stability Requirements of Polymeric Materials for Spacecraft Application

2.1.3 Program Documents

2.1.4 Drawings (Appendix C)

GN-IC-0100 Thermal Vacuum Chamber Gravity Offloader ICD

GN-IC-0101

ASA Flange, Size 8 Blank Flange Passthrough

GN-IC-0102 T-Slot Floor Gravity Offloader ICD

2.1.5 Other Publications

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2.2 Non-Government Documents

The following documents form a part of this document to the extent specified herein. In the event of conflict between the documents referenced herein and the contents of this document, the contents of this document shall be considered a superseding requirement. Copies of specifications, standards, drawings, and publications required by suppliers in connection with specified procurement functions should be obtained from the contracting agency or as directed by the contracting officer.

2.2.1 Specifications and Standards

Number Title

ANSI/ISO/ASQC Q9001 Quality Management Systems: Requirements

ASTM E595-93

Standard Test Method for Total Mass Loss and Collect Volatile Condensable Materials from Outgassing in a Vacuum Environment

IEST-STD-CC1246 Product Cleanliness Levels – Applications, Requirements, and Determination

ISO 14644 Cleanroom Standards

2.2.2 Drawings

2.2.3 Other Publications

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3.0 REQUIREMENTS

GO-274 The supplier shall provide all services, personnel, materiel, and facilities necessary for the design, analysis, development, fabrication, assembly, test, and delivery of one gravity offloading system.

Key Performance Parameters (KPPs) are requirements which are deemed most critical in order for the offloader system to meet its operational goals. KPPs should be used to guide design decisions. A summary of all gravity offloader KPPs is provided in Table 3-1, and, KPPs are not listed in any particular order.

Table 3-1. Gravity Offloader Key Performance Parameters

Req. Number Parameter Requirement Summary (see Specification for details)

GO-065 Thermal Environment

For items internal to the vacuum chamber, the gravity offloader shall perform all required functions at full specified levels of accuracy and performance while the chamber shroud and UUT are at the operating temperature range of; Threshold: -45°C to +85°C, Goal: -160°C to +85°C.

GO-066 Thermal Environment

For items internal to the vacuum chamber, the gravity offloader shall be capable of performing all required functions at full specified levels of accuracy and performance after the chamber shroud and UUT are at the survival temperature range of, Threshold: -65°C to +105°C, Goal: - 160°C to +105°C.

GO-068 Vacuum Environment For items internal to the vacuum chamber, the gravity offloader shall meet all performance requirements in a vacuum at pressures as low as 2 x 10-7 torr.

GO-209

Capability to

Incorporate Additional Lift Points

The gravity offloader shall be capable of accommodating an additional three offload lift points (offload lift points two, three, and four).

GO-211

Lift Point Relative

Proximity

The first offload lift point shall be designed such that when a second offload lift point is added to the system, the offloader lift points shall be able to be positioned less than 58.4 cm (23 in) from each other (GO- 081).

GO-072 Payload Mass Each offload lift point shall be able to offload from 0 to 200 kg (0 to 441 lbm).

GO-212 Offloading Accuracy

For masses greater than 1.0 kg and less than or equal to 125 kg, the maximum allowable offloader offset and noise errors applied by the gravity offloader at any offload lift point in any direction shall each be no more than +/- 1.23 N.

GO-078 Range of Motion When configured with a single offloaded lift point, that single offloaded lift point shall be able to translate everywhere within a minimum 254 cm (100 in) wide by 762 cm (300 in) long by 254 cm (100 in) high volume.

GO-213

T-Slot Floor Range of

Motion

When configured for use outside the thermal vacuum chamber over the T-slot floor, all lift points shall have a vertical range of motion of at least 254 cm (100 in), with the “ceiling” of this range of motion at least 463 cm (190 in) high.

GO-082 Continuous Velocity

All gravity offloader lift points shall be able to translate continuously within the entire range of motion, in any direction, and with the maximum mass as defined in GO-072 at the following velocity range;

Threshold: 0.1 to 3.0 cm/sec (.04 to 1.2 in/sec); Goal: 0.01 to 3.0 cm/sec (.004 to 1.2 in/sec).

GO-083 Max Velocity All gravity offloader lift points shall be able to translate in any direction for 10 seconds at 10.0 cm/sec (3.94 in/sec) with the maximum mass as defined in GO-072.

GO-249 Safe Modes Options

Each axis (X, Y, and Z) shall be capable of independently safing to any combination of the following three states:

Free = Motors off, brakes disengaged Active = Offload for Z, Actively following for X or Y Brake = Brakes engaged (no power applied), no motion allowed

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Req. Number Parameter Requirement Summary (see Specification for details)

GO-133 Safe Mode Response

The console shall accommodate a manual entry to independently choose for each offload lift point, based on the safe mode responses detailed in GO-249, how each controlled axis of the gravity offloader will respond to an input power loss, Emergency Disable, exceeding the maximum expected values in GO-250, or hitting the soft stops defined in GO-123 and GO-124.

3.1 Mechanical

3.1.1 Thermal Vacuum Chamber Interfaces

GO-004 The gravity offloader structural interface to the NRL thermal vacuum chamber shall be as defined in GN-IC-0100.

See Appendix C for all Interface Control Drawings.

GO-005 The gravity offloader system shall use a maximum of three port plates (per GN-IC-0101) to pass utilities (power, data, and fluids) through the thermal vacuum chamber pressure vessel.

Additional port plates may be available with NRL approval.

See Appendix C for all Interface Control Drawings.

GO-006 All connectors used to interface with the thermal vacuum chamber shall be hermetic and vacuum compatible.

GO-220 All connectors used to interface with the thermal vacuum chamber shall be Electrical Hipot tested at 600V AC.

GO-221 All connectors used to interface with the thermal vacuum chamber shall be vacuum leak tested to He MSLD < 1x10-8 cc/sec STP.

Relevant connector suppliers will typically perform testing defined in GO-220 and GO-221 prior to delivery.

Examples of relevant hermetic passthrough connector suppliers are Douglas Electrical Components, Deutsch, and Glenair.

Examples of these for the data connectors are the 37 pin Deutsch connectors, part number DS07-37S-059 for the outside and part number 13084-37S-5020 for the inside, both with part number 0603-34-2039 for copper contacts and part number 105372 for copper and constantan contacts.

GO-222 NRL shall review and approve all connectors used to interface with the thermal vacuum chamber.

GO-007 All power, data, and fluid connectors used to interface with the thermal vacuum chamber shall be Commercial Off The Shelf (COTS) hardware unless prior written approval is obtained from the procuring activity.

It is preferred that the power and data use separate thermal vacuum chamber connectors for passing through the thermal vacuum chamber pressure vessel.

GO-008 The thermal vacuum chamber ports shall be ASA 8 inch flanges with all connectors located as shown in GN-IC-0101.

The supplier will provide whatever port plates that are required to support the offloader functionality in the TVAC chamber. The “Kurt J. Lesker Company” offers blank chamber port plates (part number ASA1350X00).

GO-009 Any fluid systems used in the thermal vacuum chamber shall operate using only dry nitrogen gas.

GO-010 If the gravity offloader does utilize a fluid system, the total leak rate inside the thermal vacuum chamber shall be less than 0.15 Torr-L/sec across the full operational and survival temperature ranges defined in Section 3.5.1.

3.1.2 Laboratory Interfaces

GO-011 The gravity offloader shall accommodate a bolted interface to hard points in a laboratory floor.

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The pattern of the bolted interface will be negotiated between the supplier and NRL.

GO-012 The supplier shall provide adapters between the gravity offloader and the T-slot floor as defined in

GN-IC-0102.

See Appendix C for all Interface Control Drawings.

3.1.3 Mass

GO-013 The total mass of the gravity offloader components that are internal to the thermal vacuum chamber shall be less than or equal to 4,082 kg (9,000 lbm).

If this requirement significantly drives cost or complexity it may be acceptable, upon NRL approval, for the total mass of the gravity offloader components that are internal to the TVAC chamber to exceed 4,082 kg (9,000 lbm) if the heaviest assembly required to be lifted by the overhead crane is less than or equal to 4,082 kg (9,000 lbm).

Rationale: this is to ensure the entire offloader can be lifted by a 4,536 kg (10,000 lbm) overhead crane during installation into the TVAC chamber.

GO-224 When resting on the laboratory floor (ambient temperature and pressure), the maximum pressure the offloader shall exert on the laboratory floor is 28.7 kPA (600 psf).

As an example of an acceptable way to satisfy this requirement, if the gravity offloader is 4,082 kg (9,000 lbm), a 46 cm2 (1.5 ft2) plate of adequate thickness (to be determined by the supplier) under each of the eight structural supports would result in a distributed pressure of 23.9 kPA(500 psf).

Plates used to distribute the pressure loading on the floor are not included in the mass of the offloader.

Offloaded mass, force error, and offloader dynamics should be included in this analysis.

GO-014 The maximum mass supported by any of the eight (as defined in GN-IC-0100) thermal vacuum chamber lower pedestals shall be less than 1,361 kg (3,000 lbm).

If this requirement significantly drives cost or complexity it may be acceptable, upon NRL approval, to exceed this value, but additional NRL analyses would be required to assess this. Offloaded mass, force error, and offloader dynamics should be included in this analysis.

GO-208 The suspended static mass from each of the eight 0.625” diameter threaded holes in the ceiling of the TVAC chamber (shown in GN-IC-0100) shall be less than 90 kg (198 lbm).

This results in a total suspended static mass for all eight of the threaded holes combined of 720 kg (1,584 lbm). Any dynamic loads resulting from movement of the gravity offloader will have to be taken into account. These locations can only withstand a purely vertical load.

GO-219 There shall be no lateral loading of the eight 0.625” diameter threaded holes in the ceiling of the TVAC chamber (shown in GN-IC-0100).

3.1.4 Design Loads

GO-015 The gravity offloader shall be designed to factors of safety of three times design limit load for ultimate and two times design limit load for yield.

GO-016 An additional fitting factor of 1.15 shall be applied to single-point failure joints.

GO-017 The gravity offloader shall be designed for a seismic loading of 0.5 g in any lateral direction.

GO-018 The gravity offloader shall be proof tested to 1.75 times the design limit load of each offload lift point with the loads applied simultaneously in the configuration that produces the maximum stress in the gravity offloader.

3.1.5 Assembly and Installation

GO-268 The supplier shall provide any unique handling equipment needed for installation in the TVAC chamber or ambient lab environment.

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GO-225 The gravity offloader shall be capable of being assembled on the laboratory floor using only a 907 kg (2,000 lbm) capacity overhead crane, supplier-provided assembly aids, and hand tools each in less than 5 working days by a team of no more than four people.

GO-226 The gravity offloader shall be capable of being disassembled on the laboratory floor using only a 907 kg (2,000 lbm) capacity overhead crane, supplier-delivered assembly aids, and hand tools each in less than 5 working days by a team of no more than four people.

Rationale: There is a 907 kg (2,000 lbm) capacity overhead crane in the robotics lab high bay

If this significantly drives cost or complexity, this may be negotiable with approval from NRL.

GO-019 The gravity offloader shall be capable of being assembled for use in the thermal vacuum chamber using only a 4,536 kg (10,000 lbm) capacity overhead crane, supplier-delivered assembly aids, and hand tools each in less than 5 working days by a team of no more than four people.

GO-227 The gravity offloader shall be capable of being disassembled for use in the thermal vacuum chamber using only a 4,536 kg (10,000 lbm) capacity overhead crane, supplier-delivered assembly aids, and hand tools each in less than 5 working days by a team of no more than four people.

If this significantly drives cost or complexity, this may be negotiable with approval from NRL.

Rationale: As depicted in GN-IC-0100, there is a 4,536 kg (10,000 lbm) capacity overhead crane in front of the thermal vacuum chamber that services the clean room. There are also air barges available that can support either a single 10 foot by 10 foot cart, or two 10 foot by 6 foot carts. The air barges are moved to the front of the chamber so that the carts can be rolled into the chamber on the chamber’s rails. The procuring activity’s technicians will perform the actual installation with guidance from supplier personnel.

Note: The overhead crane in the TVAC clean room is only accessible under the door in the ceiling of the clean room and does not have access to the area immediately in front of or the interior of the TVAC chamber.

GO-020 The gravity offloader shall be capable of being installed into the thermal vacuum chamber using the rail system, rolling carts, air barge, supplier-delivered assembly aids, and hand tools each in less than 5 working days by a team of no more than four people.

GO-228 The gravity offloader shall be capable of being removed from the thermal vacuum chamber using the rail system, rolling carts, air barge, supplier-delivered assembly aids, and hand tools each in less than 5 working days by a team of no more than four people.

If this significantly drives cost or complexity, this may be negotiable with approval from NRL.

GO-021 The gravity offloader shall be installable into and removable from the thermal vacuum chamber without removal of or damage to the chamber and chamber shroud.

GO-229 The supplier shall provide an assembly plan for ambient installation and test.

GO-230 The supplier shall provide a plan for assembly for use in the thermal vacuum chamber that includes plans for installing the gravity offloader into the thermal vacuum chamber.

GO-231 All assembly and installation plans defined in Section 3.1.5 shall be provided in accordance with Section 3.8.1.

GO-022 Any component heavier than 22.7 kg (50 lbm) shall have lifting provisions such as threaded or through holes for installing hoist rings, forklift pockets, etc.

GO-023 All fasteners shall be made from corrosion resistant material.

GO-024 All structural bolted joints shall have locking features.

GO-025 Specific torque requirements for the gravity offloader assembly shall be called out on the engineering drawings and assembly procedures.

3.2 Electrical

3.2.1 Power

GO-026 The gravity offloader shall operate from standard single-phase or three-phase power.

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GO-027 The supplier shall specify their power requirements in their proposal, and updates in subsequent design reviews as specified in Table 3-6.

The thermal vacuum chamber and T-Slot floor facility have access to the same power sources, which includes two 208 VAC three-phase 100 amp circuits, 480 V, two 208 VAC single-phase 30 amp circuits, and multiple 110 VAC 15 amp circuits.

The Robot Lab power has access to 110 VAC and 208 VAC three-phase 100 amp (with disconnect outlet Pass and Seymour PS5100MIR9W) and other circuits such as 220V upon request.

Note: More amperage may be available upon request.

A gravity offloader lift point is shown in Figure 1-3.

GO-028 The gravity offloader lift point(s) shall be connectable to ground with a resistance of less than one ohm.

Rationale: In some testing contexts, it will be desired to ensure that the offload lift point is at the same potential as the Unit Under Test (UUT), which can be achieved by connecting them both to ground.

GO-029 The gravity offloader lift point(s) shall be isolatable from ground with a resistance of greater than one megaohm.

Rationale: In some testing contexts, it will be desired to ensure that the offload lift point does not act as a sneak path for current from the UUT, which can be achieved by ensuring it is not connected to ground.

If this requirement significantly increases cost or complexity this is negotiable upon NRL approval.

GO-233 The gravity offloader structure shall be grounded to the TVAC chamber at Datum A as defined in GN-IC-0100 with a resistance of less than one ohm.

GO-234 The gravity offloader power and grounding shall be implemented so as to ensure personnel safety during setup and operation.

Rationale: It is at the supplier's discretion as to how to architect the ground connections or lack thereof between main and secondary power, provided that required telemetry meets the requirements and that there is no shock or other electrical hazard to staff during setup and operation of the gravity offloader

GO-235 The supplier shall provide a grounding diagram of the gravity offloader system.

3.2.2 Data

GO-267 The control system shall accept a Network Time Protocol (NTP) input signal for time synchronization of recorded telemetry data.

This will provide a means of syncing the offloader and the UUT data.

3.2.3 Parts

GO-031 The supplier shall not use obsolete parts.

3.2.4 Harness and…