structural margins or related evaluations on other 
hardware 
N N N 
Failure of part causes only minor inconvenience operations N N N 
Failure of part does not cause debris or contamination concerns N N Y 
Failed part would not require repair or replacement N Y Y 
Part is not a protoflight article N N Y 
Load environments are defined N Y Y 
Part is not exposed to environment with potential for material degradation over 
the expected service life 
N Y Y 
Part is not primary structure N Y Y 
Part does not serve as redundant structure for fail-safe criteria per NASA-STD-
5019 
N Y Y 
Part is not designated “Non-Hazardous Leak Before Burst” per NASA-STD-5019 N Y Y 
Part does not serve as primary or secondary containment N Y Y 
Part is not subjected to impact loads N Y Y 
Part has no printed threads N Y Y 
Part is not a fastener nor does it serve the purpose of a fastener N Y Y 
If a structural analysis is required, margin of safety ultimate tensile strength 
(UTS) >6 on local maximum principal tensile stress 
N Y Y 

B.4 FRACTURE CONTROL 

The fracture control assessment methodology remains consistent for all part classes, per NASA-
STD-5019A. This applies to all systems, regardless of mission class, for applications such as 
propellant tanks and is governed by range safety requirements at NASA’s launch sites. Regardless 
of additive manufacturing process methodology, the same screening approach applies; see Figure 7, 
Fracture Control Classification logic Diagram (NASA-STD-5019A). The risk classification 
methodology above for Class C parts is intentionally designed to avoid allowing fracture critical 
hardware to be downrated to a lower risk posture, so that it does not conflict with other NASA 
policies. Any questions regarding appropriate fracture control classification should be directed, early 
in the design process, to the relevant NASA M&P Engineering staff, for appropriate adjudication. 
Not all NASA Centers maintain active Fracture Control Boards, so expertise may be required from 
another NASA Center to properly rate a piece of hardware. 


Figure 7—Fracture Control Classification Logic Diagram (NASA-STD-5019A) 


B.5 APPLICABLE TECHNOLOGIES 
Given the different risk postures that can be tailored for non-crewed missions, more leeway can be 
given for use of alternate additive manufacturing technologies. Table 22 contains a listing of the risk 
postures recommended by NASA; the risks that a given project is willing to undertake must be 
discussed with the relevant NASA M&P Engineering Staff prior to choosing a less-well-
characterized processing approach. Table 23 provides applicable AM technologies and materials 
types by part class. 
Table 23—Applicable AM Technologies and Material Types by Part Class 
    Class 
Category Technology  Materials Type A B C 
Metals L-PBF  Powder X X X 
 DED  Wire X X X 
 DED  Blown Powder X X X 
 EB-PBF  Powder   X 
Polymers L-PBF  Polymer 
Powder 
 X X 
 Vat 
Photopolymerization 
 Photopolymer 
Resin 
  X 
 Material Extrusion  Filament   X 
 Polyjetting  Various   X 

Additionally, ceramic additive manufacturing, while disallowed for use in crewed spaceflight, may 
be considered for non-crewed spaceflight, particularly for non-structural applications such as 
science instruments, where it can enable alternate sensor designs or similar activities. The process 
approach has to be well-understood, as well as properly characterizing the part class, per section 
4.3.13 of this NASA Technical Standard.  


APPENDIX C 

REFERENCES 

C.1 PURPOSE 

This Appendix provides references to guidance documents related to this NASA Technical 
Standard. 

C.2 REFERENCES 

NPR 8705.4, Risk Classification for NASA Payloads 

NPR 8715.3D, NASA General Safety Program Requirements 

NPD 8730.5, NASA Quality Assurance Program Policy 

NPR 8735.2, Management of Government Quality Assurance Functions for NASA Contracts 

NPR 6000.1, Requirements for Packaging, Handling, and Transportation for Aeronautical and Space 
Systems, Equipment, and Associated Components. 

NRRS 1441.1, NASA Records Retention Schedules (Refer to NPR 1441.1) 

NASA-STD-5006, General Welding Requirements for Aerospace Materials 

NASA-STD-5012, Strength and Life Assessment Requirements for Liquid-Fueled Space Propulsion 
System Engines  

NASA-STD-7012, Leak Test Requirements 

NASA-STD-8709.20, Management of Safety and Mission Assurance Technical Authority (SMA 
TA) Requirements 

MSFC-SPEC-164, Specification for Cleanliness of Components for Use in Oxygen, Oxidizer, Fuel, 
and Pneumatic Systems  

MSFC-STD-3716, Standard for Additively Manufactured Spaceflight Hardware by Laser Powder 
Bed Fusion in Metals 

MSFC-STD-3717, Specification for Control and Qualification of Laser Powder Bed Fusion 
Metallurgical Processes  


MSFC Form 4657, Change Request for a NASA Engineering Standard 

DOT/FAA/AR-03/19, “Material Qualification and Equivalency for Polymer Matrix Composite 
Material Systems: Updated Procedure  

MIL-STD-882E, System Safety  

AIAA S-080, Space Systems - Metallic Pressure Vessels, Pressurized Structures, and Pressure 
Components 

ASME Y14.41, Digital Product Definition Data Practices: Engineering Product Definition and 
Related Documentation Practices 

ASME V&V 40, Assessing Credibility of Computational Modeling through Verification and 
Validation: Application to Medical Devices 

ASTM B243, Standard Terminology of Powder Metallurgy 

ASTM D648, Standard Test Method for Deflection Temperature of Plastics Under Flexural Load in 
the Edgewise Position 

ASTM D792, Standard Test Methods for Density and Specific Gravity (Relative Density) of 
Plastics by Displacement 

ASTM D1505, Standard Test Method for Density of Plastics by the Density-Gradient Technique 

ASTM D5045, Standard Test Methods for Plane-Strain Fracture Toughness and Strain Energy 
Release Rate of Plastic Materials 

ASTM E3166, Standard Guide for Nondestructive Examination of Metal Additively Manufactured 
Aerospace Parts After Build. 

ASTM F1877, Standard Practice for Characterization of Particles 

AWS B4.0, Standard Methods for Mechanical Testing of Welds  

IEST-STD-CC1246, Product Cleanliness Levels - Application, Requirements, and Determination  

ISO 1183, Plastics - Methods for determining the density of non-cellular plastics - Part 2: Density 
gradient column method 

ISO/ASTM 52921, Standard Terminology for Additive Manufacturing—Coordinate Systems and 
Test Methodologies 


SAE AS9102, Aerospace First Article Inspection Requirement