540-PG-8700.2.1E_Admin_Rev.pdf

DIRECTIVE NO. 540-PG-8700.2.1E APPROVED BY Signature: Original Signed by:

EFFECTIVE DATE: December 10, 2018 NAME: Felicia Jones

EXPIRATION DATE: March 6, 2023 TITLE: Director of Applied Engineering and

Technology Directorate

CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT

http://gdms.gsfc.nasa.gov TO VERIFY THAT THIS IS THE CORRECT VERSION PRIOR TO USE.

08/16

Center-wide

Procedures and Guidelines (PG)

COMPLIANCE IS MANDATORY

Responsible Office: Code 540/Mechanical Systems Division

Title: Design and Certification of Dollies, Stands, and Shipping Containers

PREFACE

P.1 PURPOSE

The purpose of this Center-wide PG is to document the design requirements for all Dollies, Stands, and Shipping

Containers designed at GSFC for use at GSFC, as well as certification requirements for that hardware and for similar Commercial-Off-The-Shelf (COTS) hardware.

P.2 APPLICABILITY

This Center-wide PG applies, with the exception noted below, to all Mechanical Ground Support Equipment

(MGSE) Dollies, Stands, and Spacecraft Shipping Containers designed for use at the Goddard Space Flight Center

(GSFC). It also applies to the certification requirements for this hardware, as well as similar COTS hardware.

Wallops Flight Facility, Suborbital and Special Orbital Projects Directorate (SSOPD) and their component facilities and field sites in support of SSOPD programs and projects follow SSOPD 800-PG-8700.0.2.

This directive is not a substitute for applicable Occupational Safety and Health Administration (OSHA) and

National Consensus Standards (NCS) and other applicable code requirements related to the use of MGSE.

When invoked as a contractual requirement, this directive is applicable to the extent specified in the contract.

P.3 AUTHORITY

a. NPR 8715.3, NASA General Safety Program Requirements

b. GPR 8700.2, Design Development

P.4 APPLICABLE DOCUMENTS AND FORMS

a. 541-PG-8072.1.2, GSFC Fastener Integrity Requirements

b. AFSPCMAN 91-710 Vol. 3, Range Safety Users Requirements, Launch Vehicles, Payloads & GSE

c. ASTM A574, Standard Specification for Alloy Steel Socket-Head Cap Screws

d. GPR-1400.1, Waiver Processing http://gdms.gsfc.nasa.gov/

DIRECTIVE NO. 540-PG-8700.2.1E Page 2 of 19

EFFECTIVE DATE: December 10, 2018

EXPIRATION DATE: March 6, 2023

e. MIL-HDBK-1791, Designing for Internal Aerial Delivery in Fixed Wing Aircraft

f. MSFC-STD-3029, Guidelines for the Selection of Metallic Materials for Stress Corrosion Cracking

Resistance in Sodium Chloride Environments

g. NASA-STD-5005, Standard for the Design and Fabrication of Ground Support Equipment

h. NASA-STD-8719.24, NASA Expendable Launch Vehicle Payload Safety Requirements

P.5 CANCELLATION

540-PG-8700.2.1 C, Design of Dollies, Stands, and Shipping Containers

P.6 SAFETY

N/A

P.7 TRAINING

P.8 RECORDS

Record Title Record Custodian Retention

Stress Analysis Either Owners, Project Managers, Product Design Leads (PDLs), or

Designee

NRRS 8/103.

Engineering test and evaluation data.

Temporary. Destroy between 5 and 30 years after program/project termination.

Tipping Analysis Either Owners, Project Managers, PDLs, or Designee

NRRS 8/103.

Proof Test Either Owners, Project Managers, PDLs, or Designee

NDI Report Either Owners, Project Managers, or

PDLs or Designee

* NRRS – NASA Records Retention Schedule (NRRS 1441.1)

P.9 MEASUREMENT/VERIFICATION

http://nodis3.gsfc.nasa.gov/

DIRECTIVE NO. 540-PG-8700.2.1E Page 3 of 19

PROCEDURES

In this document, a requirement is identified by “shall,” a good practice by “should,” permission by

“may” or “can,” expectation by “will,” and descriptive material by “is.”

1.0 Design/Analysis/Test

1.1 Load Requirements:

All applicable hardware (hereafter referred to as “hardware”) shall be designed with the minimum design factors listed in Table 1. Projects may use higher load factors at their discretion based upon their unique circumstances or consideration of risk.

For hardware that will also be utilized outside GSFC at other sites (i.e., Kennedy Space Center, Vandenberg Air Force Base, etc.) the design requirements from these operational centers should be identified early in the design process. For reference, consider NASA-STD 8719.24, NASA Expendable

Launch Vehicle Payload Safety Requirements. It should be noted that if the requirements from these other sites are more restrictive than those contained herein, then they shall take precedence.

The bottom portion of Table 1 also includes the factors that are to be applied to the flight hardware when interfacing to the various MGSE elements. Note the factors used for the flight hardware are much less than the factors used for the MGSE. This is due to the extreme weight penalty that would be incurred if the higher MGSE factors were to be used.

1.2 Strength Analysis

A stress analysis shall be prepared for all Dollies, Shipping Containers and Personnel Work Stands designed for use at GSFC.

The analysis shall calculate stress and/or load levels in all loaded components and tabulate margins of safety (MS) based on material allowable strengths or load capability.

MS = [Allowable stress (or Load) / (F.S. x Induced Stress (or Load)] - 1

The stress analysis of the dolly shall include the dolly’s own weight, not just the added payload weight.

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Table 1: Design Load Factors and Factors of Safety (Minimum)

1Vertical load should be combined simultaneously with lateral then longitudinal loads (Vertical DLL + Lateral DLL, Vertical DLL + Longitudinal DLL) 2 The Vertical load factors defined as -4.5/+2 g’s in MIL-HDBK-1791 are yield load factors 3 The Lateral and Longitudinal load factors defined as +/- 1.5 and +3/-1.5 in MIL-HDBK-1791 are Ultimate Load Factors and contain a 1.5 ultimate

Factor of Safety. Also, the “+” for Longitudinal direction denotes forward and “-” denotes the aft direction.

4 Dolly is assumed to be secured to the base frame while shipping container is assumed to be secured to the tractor trailer/C-5.

5 A minimum load of a) 250 lbs per person shall be used or b) an evenly distributed load of 50 pound per square foot over the total area of the stand.

6 For tipping, an analysis ultimate Factor of Safety of 1.0 (minimum) shall be used.

7 Loads to be applied independently, single direction at a time. DLLs for other aircraft shall be determined.

8 Loads to be applied in each direction independently. Gravity loading shall be combined with lateral and longitudinal load cases as shown in the table below.

Load Case (Ex: Dolly Air-ride) Vertical load (g) Lateral Load (g) Long. Load (g)

1 -2.5 0 0

2 +0.5 0 0

3 -1 ± .75 0

4 -1 0 ± 1.0

9 Design limit loads applied through system Center of Gravity

10 Minus sign denotes downward for vertical load. Vertical loads include gravity (-1g)

Item Design Limit Loads (DLL) G's9 Factor of Safety

Vertical10 Lateral Long. Tipping6 Ultimate Yield

MGSE

Dolly1 (rolling on casters/air pads)

-1.0 ± 0.1 ± 0.1 0.5 3 2

Static Stand/Dolly1 (Stationary on casters, jacks, or feet)

-1.0 ± 0.1 ± 0.1 0.5 3 2

Turnover Dolly1 (Stationary on casters, jacks, or feet)

-1.0 ± 0.1 ± 0.1 0.5 3 2

Transportation Dolly and Shipping Container (C-5)7

-3.6/+1.62 ±1.03 +2/-13 N/A4 3 2

Transportation Dolly and Shipping Container8 (Air-ride van)

-2.5/+0.5 ± 0.75 ± 1.0 N/A4 3 2

Personnel Stationary Work Stand1,5

-1.0 ± 0.1 ± 0.1 0.5 3 2

Flight Hardware Interface

Dolly1 (rolling on casters) -1.6 ± 0.25 ± 0.25 N/A 1.4 1.25

Static Stand/Dolly1 (Stationary on jacks)

-1.0 ± 0.1 ± 0.1 N/A 1.4 1.25

Transportation Dolly and Shipping Container7 (C-5)

-3.6/+1.62 ± 1.03 +2/-13 N/A 1.5 1.25

Transportation Dolly and Shipping Container8 (Air-ride van)

-2.5/+0.5 ± 0.75 ± 1.0 N/A 1.4 1.25

DIRECTIVE NO. 540-PG-8700.2.1E Page 5 of 19

1.3 Tipping Analysis

A tipping analysis shall be prepared for all dollies and work stands, including COTS.

The tipping DLL shown in Table 1 shall be applied to the Center of Gravity (CG) of the system in the worst case configuration.

For the analysis, a 1g vertical (down) load shall be applied simultaneously with the lateral .5g tipping load.

A tipping Factor of Safety of 1.0 (minimum) shall be used in the tipping MS calculation. The higher

“design” Factors of Safety do not apply to the tipping margin calculation.

1.4 Seismic Analysis

Hardware, including COTS, that will be used outside GSFC in areas susceptible to earthquakes such as the Western Range (WR, Vandenberg Air Force Base), seismic loading shall be considered.

The current seismic loading requirements for the WR are specified in AFSPCMAN 91-710 V3 are:

0.4g’s vertical and 2.0 g’s lateral. This requirement is intended for dollies which are grounded/secured to a building. The 0.5g tipping load specified in Table 1 may be used to cover possible seismic input for an ungrounded structure.

1.5 Single Point Failure (Critical) Weld

All critical welds shall have a surface NDT (i.e., magnetic particle or dye penetrant) performed before and after the initial proof test and after the periodic proof test.

During the detail design of the hardware, critical welds should be avoided where possible. If critical welds are present in the design, they should not be painted so that surface NDT may be performed.

Though not required, a safe life analysis should be considered for all S/C shipping containers and transportation dollies due to their high cyclic loading. More consideration should be given to performing this analysis on hardware that is being reused by a program that didn’t actually develop the hardware in the first place. When performing this analysis a 4X service life should be demonstrated.

1.6 Fasteners

All critical fasteners used on the hardware shall be identified and are subjected to the GSFC Fastener

Integrity Requirements (541-PG-8072.1.2). During the detail design of the hardware, critical fasteners should be avoided and fail safe fastener patterns should be used where possible. High strength (180 ksi)

ASTM A574 fasteners, such as black oxide socket head cap screws, shall not be used in primary structural applications.

Only fasteners that are made from MSFC-STD-3029 Table 1 material (such as A286, CRES, or Grade 8 steel) shall be used in primary structural applications for in-house designed MGSE.

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If for some reason the need arises to use similar 180 ksi low alloy steel fasteners in primary structural applications, the PDL shall obtain documented concurrence from the 540 Chief Engineer or designee that is to be included as part of the certification package.

1.7 Initial and Periodic Proof Tests

All new or modified hardware shall be proof tested to the levels specified in Table 2. Refer to Section

1.8 for requirements on COTS hardware.

Table 2: Initial and Periodic Load Test Factors (Minimum)

Item Initial Test Factors Periodic Test Factors

MGSE

Dolly (rolling on casters/air pads) 1.5 x Payload 1.25 x Payload

Static Stand/Dolly (Stationary on casters, jacks) 1.5 x Payload 1.25 x Payload

Turnover Dolly (Stationary on casters, jacks) 1.5 x Payload 1.25 x Payload

Transportation Dolly and Shipping Container (C-5) 1.25 x DLL N/A

Transportation Dolly and Shipping Container (Air-ride van) 1.25 x DLL N/A

Personnel Stationary Work Stand 1.5 x Payload 1.25 x Payload

Flight Hardware Interface

Dolly (rolling on casters) 1.25 x DLL N/A

Static Stand/Dolly (Stationary on jacks) 1.25 x DLL N/A

Transportation Dolly and Shipping Container (C-5) 1.25 x DLL N/A

Transportation Dolly and Shipping Container (Air-ride van) 1.25 x DLL N/A

Following all testing and prior to use, all hardware shall be visually inspected for any damage or anomalous conditions.

1.7.1 Frequency of Load Tests

The hardware shall be periodically load tested a minimum of every 4 years.

1.7.2 Extension of Load Test Frequency

The 4-year period can be extended if adequate documentation is provided to the Code 540 Chief

Engineer or designee verifying the hardware has seen limited or no usage for an extended period of time with appropriate handling, storage, and maintenance of the hardware.

1.8 Commercial-Off-The-Shelf (COTS) Hardware Requirements

In general, each program/project has the responsibility to define its own policy for the acceptance of

COTS handling Mechanical Ground Support Equipment (MGSE) that will be used for flight hardware and critical MGSE.

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However, there are a few types of COTS handling MGSE that shall meet a minimum set of testing requirements. They include:

1. Positioning tables (such as Koiki/Aronson)

2. Holding/Turnover Fixtures (such as Flotron)

It should be noted that the analysis requirements (DLL and factor of safety) of this PG do not apply to

COTS hardware.

1.8.1 COTS Operational Use

For operational use, COTS hardware shall be used below the items “nameplate rating” or the manufacturers specified Working Load Limit (WLL) or Safe Working Load (SWL). Modifications to

COTS hardware should be worked through the manufacturer of the hardware when possible. GSFC is responsible for obtaining the cited documentation (modification and proof testing) from the manufacturer.

If modifications are to be done by GSFC, then GSFC shall be responsible for performing the analysis of the modification, the review of that analysis, the actual modification of the hardware, the proof testing, and maintaining that documentation related to the modification.

MGSE hardware that supports flight hardware and critical MGSE such as handling carts, tables, bonded storage mobile shelving, etc., shall follow the project’s defined policies. It is recommended that Product

PDL responsible for the hardware include the policy of acceptance of COTS MGSE when developing the MGSE handling plan. Careful consideration should be given to proof testing COTS MGSE as the payload weight approaches the Working Load Limit. For those items that are identified by the project as requiring proof testing, the requirements noted below in sections 1.9.17 - .19 apply.

COTS MGSE while active should be maintained according to OEM recommendations and schedules. If the hardware maintenance schedule is not performed due to inactivity, prior to bringing the hardware back into an active status, a checkout/refurbishment should be performed by the OEM or equivalent.

1.8.2 Requirements for Positioning Tables with T-Slotted Interfaces

Due to the poor quality of catalog “T-nuts” which are commonly used to attach hardware to positioning tables, all GSFC positioning tables with T-Slotted interfaces shall use T-nuts made from Table 1 material with a material certification including lot traceability and chemistry/physical properties.

The fasteners that interface to the T-Nuts shall have a minimum ultimate tensile strength of at least 150 ksi, such as a Grade 8 fastener.

The T-Nut shall be designed and shown through analysis to develop the full strength of the specified mounting bolt/stud using an ultimate factor of 5 (not including preload) for both T-nut and bolt/stud.

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All T-Nuts shall be proof torque tested to at least 1.5 times the specified installation torque prior to use or proofed during the system level proof test.

A pre- and post- visual inspection shall verify that the T-Nut is crack free.

1.9 Hardware Tests

All proof tests shall be designed to develop the proper loading conditions at critical areas within the

MGSE.

The test loads shall be derived to account for the location of the payload CG relative to the MGSE interfaces as well as load sharing effects between the payload and MGSE for redundant interfaces.

Prior to initial use all new, altered, modified, or repaired MGSE shall be proof tested according to the factors in Table 1.

Certification of MGSE hardware may be extended by the Mechanical Systems Division/540 Chief

Engineer or designee after adequate documentation is provided verifying either of the following:

(1) The hardware has been idle since the last certification/load test date, appropriate handling and storage practices have been adhered to, and all recommended maintenance has been performed.

(2) The hardware contains or is connected or integrated to flight hardware when the current certification expires and cannot be freed up for proof test.

Certification shall be extended until the next time the hardware becomes available for proof testing and inspection.

1.9.1 Dolly (rolling on casters/air pads) Vertical Proof Test

The vertical strength of the dolly while on its casters/air pads shall be demonstrated through a vertical proof test performed with 1.5 times the payload mass attached to the interface.

With the proof masses attached, the dolly shall be moved around the facilities while on its castors/air pads.

1.9.2 Dolly (rolling on casters/air pads) Lateral Proof Test

The strength of the dolly while on its castors/air pads in the lateral and longitudinal directions shall be demonstrated through test or analysis using the DLL and Factors of Safety specified in Table 1.

1.9.3 Static Stand/Dolly (Stationary on jacks) Vertical Proof Test

The vertical strength of the Static Stand/Dolly (stationary on its jacks) shall be demonstrated through a vertical proof test performed with 1.5 times the payload mass attached to the interface.

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1.9.4 Static Stand/Dolly (Stationary on jacks/wheels) Lateral Proof Test The strength of the dolly while on its castors/air pads in the lateral and longitudinal directions shall be demonstrated through test or analysis using the DLL and Factors of Safety specified in Table 1.

1.9.5 Static Stand/Dolly (Stationary on jacks/wheels) Tipping Proof Test The resistance of the Static Stand/Dolly (stationary on its jacks/wheels) to tipping in the highest cg orientation shall be demonstrated through test or analysis using the DLL and Factors of Safety specified in Table 1. For the analysis, a Factor of Safety of 1.0 may be used in the tipping MS calculation.

1.9.6 Turnover Dolly (Stationary on jacks) Dynamic Rotational Proof Test

The strength of the rotational mechanism of the dolly while on its jacks shall be demonstrated through a proof test with 1.5 times the payload mass attached to the interface plane at the same CG location as the payload (one and a half times the interface moment). If both mass and moment levels cannot be accomplished in one test, two tests can be performed: (1) 1.5X mass test, and (2) 1.5X maximum moment test.

The rotational mechanism shall be operated through the full range of motion and at the maximum operational rotational speeds at proof test mass and moment levels.

1.9.7 Turnover Dolly (Stationary on jacks) Lateral Proof Test The strength of the dolly while in the lateral and longitudinal directions shall be demonstrated through test or analysis using the DLL and Factors of Safety specified in Table 1.

1.9.8 Turnover Dolly (Stationary on jacks) Tipping Proof Test.

The resistance of the turnover dolly and payload to tipping while on its jacks in the highest cg orientation shall be demonstrated through test or analysis using the DLL and Factors of Safety specified in Table 1. For the analysis, a Factor of Safety of 1.0 may be used in the tipping MS calculation.

1.9.9 Transportation Dolly and Shipping Container (C-5/other aircraft) Proof Test

For C-5 transport, the Transportation Dolly and Shipping Container while supported at their transport interfaces shall be proof tested to the system mass (payload + dolly) times the DLLs specified in Table 1 with a test factor of 1.25.

For the test, the maximum payload mass shall be assumed.

As a minimum, a test demonstrating the strength in the vertical direction shall be performed.

The lateral and longitudinal strength may be demonstrated by analysis if positive Margins of Safety using the DLL and Factors of Safety specified in Table 1 are shown.

For other aircraft, the DLLs shall be determined.

DIRECTIVE NO. 540-PG-8700.2.1E Page 10 of 19

1.9.10 Transportation Dolly and Shipping Container (Air-ride van) Proof Test

The Transportation Dolly and Shipping Container while supported at their transport interfaces shall be proof tested to the system mass (payload + dolly) times the DLLs specified in Table 1 with a test factor of 1.25.

For the test, the maximum payload mass shall be used.

As a minimum, a test demonstrating the strength in the vertical direction shall be performed.

The lateral and longitudinal strength may be demonstrated by analysis if positive Margins of Safety using the DLL and Factors of Safety specified in Table 1 are shown.

In addition to the static proof testing, the Transport Dolly and Shipping Container shall be road tested

(with a maximum payload mass attached) over similar roads that the flight payload will be transported over.

For the road test, three axis acceleration responses at the base of the container and on the isolated

Transportation Dolly should be recorded and isolation frequency verified.

1.9.11 Personnel Work Stand (Stationary) Vertical Proof Test

A vertical proof test of the Personnel Work Stand shall be performed to the levels specified in Table 1.

1.9.12 Personnel Work Stand (Stationary) Tipping Proof Test

Tipping resistance of Personnel Work Stands shall be demonstrated by test or through analysis using the

DLL and Factors of Safety specified in Table 1. For the analysis, a Factor of Safety of 1.0 may be used in the tipping MS calculation.

1.9.13 Flight Hardware/Dolly Interface (Rolling on casters/air pads) Proof Testing

The S/C side of the S/C-Dolly interface shall be tested to the levels specified in Table 1.

If the spacecraft side of the interface is not test verified then positive Margins of Safety shall be demonstrated with higher Factors of Safety of 2.0 on yield and 2.6 on ultimate.

GSE interfaces that utilize bonded joints as part of the load path shall be proof tested and cannot show verification by analysis only.

1.9.14 Flight Hardware /Dolly Interface (Stationary) Proof Testing

The S/C side of the S/C-Dolly interface shall be tested to the levels specified in Table 1.

If the spacecraft side of the interface is not test verified then positive margins of safety shall be demonstrated with higher factors of safety of 2.0 on yield and 2.6 on ultimate.

DIRECTIVE NO. 540-PG-8700.2.1E Page 11 of 19

GSE interfaces that utilize bonded joints as part of the load path shall be proof tested and cannot show

1.9.15 Flight Hardware /Transportation Dolly (C5) MGSE Interface Proof Testing.

The spacecraft interface that attaches to the Transportation Dolly (C5) shall be proof tested to the levels specified in Table 1 with a test factor of 1.25.

If the spacecraft side of the interface is not test verified then positive margins of safety shall be

GSE interfaces that utilize bonded joints as part of the load path shall be proof tested and cannot show

1.9.16 Flight Hardware /Transportation Dolly (Air-ride) MGSE Interface Proof Testing

The spacecraft interface that attaches to Transportation Dolly (Air-ride) shall be proof tested to the DLL specified in Table 1 with a test factor of 1.25.

If the spacecraft side of the interface is not test verified then positive margins of safety shall be

GSE interfaces that utilize bonded joints as part of the load path shall be proof tested and cannot show

1.9.17 MGSE Lifting Interface Testing

All MGSE lifting interfaces shall be proof tested to 1.5x the maximum expected load (payload + MGSE

+ other weight to be lifted) prior to use.

1.9.18 COTS Proof Testing

When COTS proof testing is performed, it is recommended that the testing be done at a minimum of

125% of the items “nameplate rating” or the manufacturers specified Working Load Limit (WLL, or possibly referred to as Safe Working Load, SWL). This is to establish actual “test margin” between the

WLL and the proof test load. It is also recommended that the design factors used by the COTS manufacturer be determined prior to performing the proof test. These design factors would typically be equal or greater than 2 for yield and 3 for ultimate.

If the COTS hardware has been modified or repaired in any way that would bring into question its capability to safely perform its intended functions, the COTS MGSE shall be reproofed to 125%.

Following proof testing and prior to use, all hardware shall be visually inspected for any damage or anomalous conditions. For COTS hardware with welded connections, only visual inspection (no NDI) is required.

DIRECTIVE NO. 540-PG-8700.2.1E Page 12 of 19

1.9.19 COTS Load Testing Frequency

COTS MGSE hardware requiring proof testing should be re-tested every 4 years unless adequate documentation is provided verifying the appropriate handling, storage, and maintenance of the hardware.

Also, any required maintenance specified by the manufacturer shall be performed according to the manufacturer’s recommended maintenance schedule.

Following all load testing and prior to use, all hardware shall be visually inspected for any damage or anomalous conditions.

1.9.20 Separable Assemblies

Any portion of the hardware assembly that will be disassembled after Proof Testing should be tagged/marked in some manner so that it can be reassembled identically to the tested configuration.

1.10 Best Practices

The following guidelines for the selection of materials, components and use of design rules for dollies and work platforms assemblies are recommended. NASA STD 5005, Standard for the Design and

Fabrication of Ground Support Equipment, provides many additional best practices and can be used as an additional reference.

1. Load lines should align so that local induced moments are avoided. Lines of action should intersect at the neutral axes of the members.

2. All bolted joints should be designed fail-safe where the highest loaded fastener in the pattern can be removed and the remaining fasteners can carry the load with a 1.0 factor of safety. If the joint is not fail-safe, then some method will be needed to ensure that if the fasteners are removed following the proof test, the bolts are indexed to the appropriate joints.

3. Where possible, all welds should be designed fail safe.

4. For structural elements, materials with good strain properties should be used. It should be noted that the current Range Safety Document (AFSPCMAN 91-710 V3) specifies that, “materials that have at least 20% ultimate strain need to be used. If the materials selected do not meet this minimum ultimate strain requirement, the design must include a fracture mechanics analysis that shows a service life cycle factor of safety of 100:1 and a detailed NDE surface and/or volumetric requirements.”

5. If the hardware will be utilized inside a thermal vacuum chamber during testing, box beams/closed sections should be avoided. It is difficult to properly clean the inside surfaces of box beams and box beam weldments can result in virtual leaks if not properly vented.

6. Shock Isolation Target Frequency - Target frequency for the shock isolation system should be in the 3 - 7 Hz range to avoid coupling with dynamic inputs from air-ride trucks (<2Hz and >10

Hz) and C5 aircraft (>10 Hz). Where possible, testing of the isolation system with a spacecraft mass (and center of gravity) simulator under transportation conditions should be performed to verify environments and performance of the isolation system prior to use with the flight hardware.

DIRECTIVE NO. 540-PG-8700.2.1E Page 13 of 19

7. Wire rope isolator sizing and loading – It is advisable to consult with the isolator vendor when sizing the isolators. Discussion should include the system frequency requirements, dynamic loading conditions and proof test requirements.

a. The maximum allowable static displacement should be verified with the vendor. Some vendors prefer to limit the working static displacement of the isolator to a certain percentage of the maximum rated dynamic displacement.

b. The stiffness values to be used in the selection of the isolator should be verified with the vendor. Testing of isolators indicates that the average stiffness values specified for vibration isolation (as opposed to shock isolation), which are defined based on small deflections of the isolator (10% or less of the maximum rated stroke), most accurately reflect the measured dynamic behavior of the isolated system. Load-deflection curves may be obtained from the vendor to understand the behavior of the isolator under various loading conditions.

c. Loss of clearances for the critical components should be assessed for the low isolation frequency deflections.

8. If alignment measurements are planned on the Dolly, consider incorporating a 3 point leveling jack configuration to aid alignment set-up.

9. Use swivel hoist rings in place of lifting eyes wherever possible due to the lack of lateral load capability of lifting eyes. Utilize some method of securing nuts so they don’t come loose during transportation

10. If lifting lugs are permanently attached (welded), only visual inspection will be applicable.

11. Provide dedicated grounding points (tapped holes) around the Dolly.

12. Dolly Caster Loading. To determine the caster loading on a dolly, an assumption of the dolly stiffness needs to be made. If the four wheeled dolly is very stiff out of plane, while the dolly is rolled across an uneven floor, only three wheels will contact the floor at a time and if the cg is close to the center of the footprint of the wheels, only two diagonal wheels will carry load. If the dolly stiffness is not known, the conservative loading assumption that only two diagonal casters carry the load should be made. If this assumption is felt to be too conservative for the dolly configuration, then FEM analysis using worst-case assumptions for payload weight and CG location can be used to determine the load sharing of the casters.

For example, let’s say we have a 4-wheeled dolly that has an empty weight of 1000 lbs. and is sized to carry a 1000 lbs. payload. If the dolly is very stiff out of plane, casters rated for at least

1000 lbs. should be used. If the dolly is very flexible out of plane (like a Flotron dolly) casters rated for at least 500 lbs. should be used. Please note that for this example the effect of the 0.1g lateral load has not been included for simplicity. The actual castor rated load should account for a combined loading condition as specified in Table 1.

When sizing the casters, the caster manufacturer should be contacted to determine what Factors of Safety the vendor used in their design. Also, the vendor should be contacted if the proof test will exceed the rated load of the caster for the vendor’s concurrence.

DIRECTIVE NO. 540-PG-8700.2.1E Page 14 of 19

2.0 Responsibilities

2.1 Chief Engineer, Mechanical Systems Division (MSD), or designee

a. Shall serve as the technical authority for the design requirements of this PG.

b. Shall serve as the final authority on interpretation of and compliance with this PG and its reference documents.

c. Shall serve as the technical authority for waivers and deviations from the technical requirements of this PG.

d. Shall provide an independent review of the certification documentation, maintain the documentation in a database, and issue a certification tag for the hardware.

2.2 Owners/Project Managers/Product Design Leads (PDL)

a. Shall maintain the required certification documentation for the hardware (Project, Facility, etc.).

b. Shall ensure that MGSE selected for use is suitable for its intended purpose and has been certified prior to use.

c. Shall be responsible for flowing requirements of this PG and its reference documents down to contractors, subcontractors and suppliers.

d. Shall submit the required documentation to the 540 Chief Engineer or designee to be reviewed for compliance with this PG prior to certification.

e. Will manage and control uncertified or expired MGSE by establishing administrative controls to preclude unauthorized use.

f. Will develop a policy for the acceptance of COTS MGSE when developing the MGSE handling plan.

3.0 Certification Requirements

The Certification documentation shall include, but may not be limited to, the following:

a. Signed/dated load test procedures (i.e., WOA’s, etc.)

b. Design/Assembly drawings for non-COTS MGSE

c. Manufacturer’s information (i.e. drawings, cut sheets, etc.) for COTS MGSE

d. Photographs of the actual load test in each configuration

e. Current load cell calibrations

f. Post load test inspection reports as required (i.e. NDT or in-depth visual)

g. Inspection personnel qualifications

Documentation for certification shall be available for review upon request (Chief Engineer, Safety, Quality, Facility, etc.).

DIRECTIVE NO. 540-PG-8700.2.1E Page 15 of 19

GSFC Form 23-9, found at NASA Electronic Forms (NEFs) site, web address below, may be used to assure all requirements have been addressed.

https://nef.nasa.gov/

Certification tags shall be securely affixed prior to use and will include the following information:

a. Criticality

b. A unique identification number

c. Working Load Limit (WLL)

d. Project name and brief description (optional)

e. Load test due date

4.0 Waivers

If the requirements of this PG or an equivalent standard approved by the responsible Technical

Authority cannot be met, a waiver request shall be prepared in accordance with GPR 1400.1.

Conflicts between this PG and other applicable standards and/or previous NASA program requirements may be evaluated on a case by case basis by the responsible Technical Authority against the requirements of this directive.

DIRECTIVE NO. 540-PG-8700.2.1E Page 16 of 19

Appendix A – Definitions

A.1 Catastrophic Hazard – A condition in which a failure can result in disabling or fatal personnel injury, the loss of a spacecraft or launch vehicle.

A.2 Commercial-Off-the-Shelf (COTS) – Equipment that is commercially available from industrial inventory at the time of purchase.

A.3 Critical Fastener – A fastener where the single failure would result in a Catastrophic Hazard.

A.4 Critical Mechanical Ground Support Equipment – Mechanical Ground Support Equipment

(developed or procured) used in support of product development that is in direct contact with or in close proximity to the product and having properties such that inadequate design or manufacture, malfunction, improper function, or failure of which could cause personnel injury or product damage.

A.5 Critical Weld – A weld where the single failure of which could result in disabling or fatal personnel injury or damage to property or flight hardware.

A.6 Fail Safe Fastener – A condition where, after failure of a single fastener, the remaining fasteners can withstand the redistributed loads and the failure will not release a potentially catastrophic free body.

A.7 Mechanical Ground Support Equipment – Non-flight mechanical equipment, systems, or devices specifically designed and developed for a physical or direct functional interface with flight hardware.

A.8 NDT (Non-Destructive Test) – The development and application of technical methods to examine materials or components in ways that do not impair future usefulness and serviceability in order to detect, locate, measure and evaluate flaws; to assess integrity, properties and composition; and to measure geometrical characteristics.

A.9 Payload – Any flight hardware supported by MGSE.

A.10 Proof Load Test – the initial, first-time load tests of new or extensively modified LE.

A.11 Periodic Load Test – Annual load test of LE typically at the rated capacity.

A.12 Responsible Technical Authority – the Chief Engineer of the MSD or their designees.

DIRECTIVE NO. 540-PG-8700.2.1E Page 17 of 19

Appendix B – Acronyms

CG Center of Gravity

COTS Commercial-Off-The-Shelf

CPG Center-wide Procedures and Guidelines

DLL Design Limit Loads

FS Factor of Safety g’s Gravity

GPR Goddard Procedural Requirement

GSE Ground Support Equipment

GSFC Goddard Space Flight Center

I/F Interface lbf Pounds-Force

LCG Load Center of Gravity

LDE Lifting Devices and Equipment

LDEM Lifting Devices and Equipment Manager

LE Lifting Equipment

MGSE Mechanical Ground Support Equipment

MS Margin of Safety

MSD Mechanical Systems Division

MT Mag-Particle Testing

N/A Not/Applicable

NASA National Aeronautical Space Administration

NDI Non-Destructive Inspection

NDT Non-Destructive Testing

NEF NASA Electronic Forms

NRRS NASA Records Retention Schedule

OEM Original Equipment Manufacturer

PDL Product Design Lead

PG Procedures and Guidelines

PM Project Manager

PT Dye-Penetrant Testing

S/C Spacecraft

SSOPD Suborbital and Special Orbital Projects Directorate

STD Standard

SWL Safe Working Load

WLL Working Load Limit

WOA Work Order Authorization

DIRECTIVE NO. 540-PG-8700.2.1E Page 18 of 19

CHANGE HISTORY LOG

Revision Effective Date Description of Changes

Baseline

12/10/2007 Initial Release

A

09/28/2009 Revised Table 1. Removed requirement for adding an additional

1x mass equal to the dolly empty weight for the proof test. Added discussion in section D. 9 on caster sizing

B

08/16/2013 Revised transportation DLL in Table 1 and clarified methodology of load combining.

Clarified seismic loading in section D4

Added requirements for COTS hardware in D 8, D.9.17-9.18

Added discussion on wire rope isolator sizing in section D10.

C

03/09/2016 Updated to new required format

Change title of document and applicability to be Center wide

Revised design factors of safety to be consistent with NASA-STD-

Revised initial proof test factors of safety

Updated fastener requirements

Updated COTS requirements

Updated transportation dollies and spacecraft shipping containers longitudinal and lateral testing requirements

Added responsibility and waiver section

D

03/06/2018 P.2: Delineated applicability for SSOPD's process per 800-PG-

8700.0.2.

Split Table 1 into two tables for clarity

1.9.6: Clarified tests can be done for mass and moment separately.

Section 2.0: Clarified Responsibilities for the 540 Chief Engineer and designees for review, archiving, and tagging

E 12/10/2018

1) Clarified maximum expected load for proof testing in Section

1.9.17, MGSE Lifting Interface Testing.

DIRECTIVE NO. 540-PG-8700.2.1E Page 19 of 19

2) The Acronym, WLL, Working Load Limit was added to the Appendix. In addition, WLL replaced SWL (Safe Working Load) in several locations in the document.

Industry has moved away from the use of SWL and now prefers to use WLL. They are equivalent terms.