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Mission Success Starts With Safety 5/3/2015 1 Changes in Rev. A of 8739.1 NASA STD 8739.1NASA STD 8739.1A 1.

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Presentation on theme: "Mission Success Starts With Safety 5/3/2015 1 Changes in Rev. A of 8739.1 NASA STD 8739.1NASA STD 8739.1A 1."— Presentation transcript:

1 Mission Success Starts With Safety 5/3/ Changes in Rev. A of NASA STD NASA STD A 1

2 Mission Success Starts With Safety 5/3/ Standards Scope Requirements apply to Staking & Conformal Coating only. Additional requirements for Fastener Locking & Striping, Bonding and Potting were placed in the Student workbook. Standard was reformatted to conform with new NASA STDs format. Integrated all the Polymeric Applications in one standard. Identify all unique requirement in the standard. All Design Rules were moved to one section NASA STD NASA STD A 2

3 Mission Success Starts With Safety 5/3/20153 Change & Rationale Conflicting / Repeated requirements Separate Requirements are called out in same paragraph Non verifiable requirements Consolidated Common Requirements to all Polymeric Applications Separate paragraph for each unique requirement Deleted non-enforceable requirements NASA STD NASA STD A 3

4 Mission Success Starts With Safety 5/3/ Change & Rationale Requirements embedded in Tables, Notes and Figures Incorrect or outdated references and acronyms Some drawings and images were not instructive. All requirements are spelled out in the body of the standard with Tables, notes and figures used to clarify the requirement Updated all references and acronyms used within the standard Updated photographs and graphics (most require digital viewing) NASA STD NASA STD A 4

5 Mission Success Starts With Safety 5/3/20155 Change & Rationale Quality Assurance Section contained Inspection Requirements not in the body of the standard QA Section Inspection Requirements is a summary of all Inspection requirements Deleted Outdated Improvement Proposal form NASA STD NASA STD A 5

6 Mission Success Starts With Safety Specific Changes or Additions 5/3/20156  New Paragraph declares that all exceptions or additions to the minimum requirements for staking must be documented on the engineering drawings. The drawings must state the staking material and locations to where it is to be used. (also added to ).  New Requirement, the NASA Center or its designated representative shall approve all rework procedures before they are used.  New Para ESD ANSI/ESDA S20.20 ( ) is now applicable to all NASA contracts. For GSFC internal work, the ESD Control Program required by S20.20 is GSFC WM-001B (http://workmanship.nasa.gov )  = new requirement

7 Mission Success Starts With Safety 5/3/20157 Specific Changes or Additions Paragraph 4.5 Design and Material Selection Requirements consolidated and simplified.  New requirement: materials must be able to achieve coverage, volume control and bond line control.  QPL (conf. coat material) is no longer maintained so it was removed.  The training and certification will now also apply to bonding and encapsulation. Section 6.1 on SAFETY was reformatted and clarified, redundant requirements were eliminated. Figure 6.2 Working Zone was eliminated and the actual range for temperature and RH in words in Para  = new requirement

8 Mission Success Starts With Safety Specific Changes or Additions Section 6.4 was created to consolidate all Silicone Operation requirements and warnings.  Paragraph 6.7.3: allows use of oblique lighting (rather than shadowless) if specified by the engineering instructions.  Paragraph Requirement for optical elements to be glass-only was deleted. Magnification requirement moved from quality assurance checklist in the last chapter (Ch 11) to Inspection Optics section. Mag level expanded to allow unaided inspections if needed (  1X to 10X). (it was 4X to 10X) 5/3/  = new requirement

9 Mission Success Starts With Safety 5/3/20159 Specific Changes or Additions Paragraph 6.9. Solvents: Requirement statements broken out into individual subpara’s.  Specific requirement added about not contaminating electrically active contacts surfaces.  Paragraph 6.9.8: Requires the use of forced dry nitrogen or equivalent immediately after use of a deionized water cleaning step  Table 6-1: Methyl and Butyl Alcohol removed Table 6-1: Note that the specification for Isopropyl alcohol is incorrect. TT-I-735 is the correct spec. (This specification was reactivated after A publication date).  = new require.  = new requirement

10 Mission Success Starts With Safety Specific Changes or Additions  Paragraph Statement about solvent check in degreasing system deleted: too vague.  Paragraph 7.1.6: Disallows the use of immersion cleaning for silver-plated wire to avoid red-plague.  Paragraph 7.1.7: Instructs about how to seek approval for alternate cleaning processes (e.g. plasma) 7.3 Testing Frequency was deleted. It was contradictory with the “All PWA’s shall be tested” statement in 7.2. Section 8.0: All preparation instructions consolidated into this section. Requirements for samples contained here as well. 5/3/  = new requirement

11 Mission Success Starts With Safety Specific Changes or Additions  8.1 Surface Preparation : Follow instructions in engineering drawings. Suggested pre-conformal coat bake schedule provided (Table 8-1). Time in and out of baking chamber shall be recorded. Storage in moisture-controlled chamber for periods following bake-out is allowed. Suggested bake-out schedules (Table 8-1): Ramp- up /ramp-down times are minimum times and indicate the point at which thermal shock damage may occur. 5/3/2015  = new requirement11

12 Mission Success Starts With Safety 5/3/ Specific Changes or Additions  Mixing multicomponent materials: Air entrapment shall be minimized. Warning about losing volatile ingredients during dearation.  Mix Record now also shall include: Manufacturer’s name, Time at mixing, Ambient Conditions (T/H) at mix time, Traceability to Test Specimen, Special Allowances.  8.5 All references to Witness Sample, Test Coupon and Control Specimen were moved to this section. Terminology is now Test Specimen and Conformal Coating Specimen.  = new requirement

13 Mission Success Starts With Safety Changes to Test Specimen Requirements NASA STD (August 6 th, 1999) – Control Specimen refers to the Test Specimen (Witness Sample) prepared when the material is received. – Witness Sample is the Test Specimen prepared at the same time as the final work is done. – Test Coupon is the Test Specimen prepared to test for Hardness measurements. It is also a record for proper curing of bonding and encapsulation materials. NASA STD A (March 3 rd, 2008) – 8.5 Test Specimen created at the same time and with same processes as batch used on flight hardware. Hardness tested (except conformal coating materials). Stored as a record. – 8.6 Conformal Coating Specimen processed along with flight hardware. Stored as a record. 5/3/201513

14 Mission Success Starts With Safety After material qualification the Test Specimen & Mix Record are stored for reference. When a new batch is mixed the new Mix record compared to the one done at Qualification. The mix record new (additional) requirements are: – Manufacturer’s name – Time at mixing date) – Ambient Conditions (T/H) at mix time – Traceability to Test Specimen – Special Allowances. Changes to Test Specimen Requirements 5/3/ Materials Received 2. Qualification Mix Record prepared 3. Materials stored 4. Batch Mixed & Record prepared 5. Material Applied & Test Specimen & Conf. Coat Specimen prepared 7. QA Inspect & Approve 8. Curing period 9. QA Inspect & Approve REQUIRED Suggested 14  = new requirement

15 Mission Success Starts With Safety 5/3/ Specific Changes or Additions Section 9 STAKING: requirements from the images were captured in the text. The only required staking is for wire runs and axial tantalum capacitors. All other staking inspection criteria applies If/When staking is called out for that type of part in the engineering drawings.  Paragraph 9.1.1: Staking must be done prior to conformal coating (unless otherwise described on the engineering documentation). Added Section 9.2 FASTENER STAKING, with requirements similar to the recommendations currently in the Student Workbook.  = new requirement

16 Mission Success Starts With Safety Specific Changes or Additions  Paragraph d: Warning about preventing thread lubricant from inhibiting staking adhesion.  Paragraph e: Warning about covering mounting or venting holes with staking material  Added Section 9.3 TORQUE STRIPING, with requirements similar to the recommendations currently in the Student Workbook Curing. Humidity requirement was deleted as it depends on the materials used. 5/3/2015  = new requirement16

17 Mission Success Starts With Safety Specific Changes or Additions Paragraph 10.2.b: The requirement to use only natural bristles brushes has been deleted. Requirement reworded to assure brush is selected for coverage control, can be cleaned and dried.  Paragraph b: Allows variances in brush coating thickness (to be specified in the engineering documentation). Paragraph : Use Ultraviolet (UV) light illumination to verify coverage of fluorescent conformal coating. Replaces old Para /3/  = new requirement

18 Mission Success Starts With Safety 5/3/ Specific Changes or Additions  New Section 11 on BONDING has been added to formalize requirements found on the student workbook.  New Section 12 on ENCAPSULATION has been added. Includes vacuum degassing, pre-cure inspection requirements and post-cure inspection requirements Section 14 Quality Assurance section cleaned up to track 1-to-1 with all requirements in prior sections and to contain no requirements not previously defined.  = new requirement


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