Lesson Learned and Prop Stand TIM 6-13-25 R3.pptx
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This document is a NASA presentation and standard outlining lessons learned and technical requirements for controlling catastrophic hazards in human-rated spacecraft propulsion systems. The comprehensive standard (JSC-67723) consolidates existing NASA, military, and aerospace industry technical standards, addressing gaps and incorporating lessons learned from previous spaceflight programs like Apollo, Space Shuttle, and ISS.
NASA is hosting a virtual Technical Interchange Meeting (TIM) on June 13, 2025, from 9:00am to 12:00pm to engage industry feedback on the new propulsion system standard. Interested companies must RSVP by June 11, 2025, at 4:00pm Central time to jsc-dl-prop-std-TIM-rsvp@mail.nasa.gov. The standard covers various propulsion system elements including fluid compatibility, materials, valve requirements, engines, instrumentation, and electrical systems, with a focus on preventing catastrophic failures across different spacecraft propellant types such as hydrazine, oxygen, methane, and hydrogen. Companies are invited to review the documents and submit feedback using the JSC-67723-Propulsion-Standard.xls response form to Eric Hurlbert by June 30th.
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| File | Type | Posted |
|---|---|---|
| Q _A Engineering Propulsion Standards TIM 6-13-2025.pdf | ||
| Lesson Learned and Prop Stand TIM 6-13-25 R3.pdf | ||
| JSC-67723_Propulsion_Standard_Basic_Final.pdf | ||
| JSC-67723-Propulsion-Standard-Response-Form.xlsx | XLSX spreadsheet |
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Lessons Learned and Gaps in Standards Related to Controlling Catastrophic Hazards for Human Spacecraft Propulsion Systems 6-13-2025 Presentation to Industry TIM
Eric Hurlbert / JSC EP4 John Albright / JSC EP4 Trivector With inputs from the NASA propulsion community Public Use Permitted Public Release Statement
This document has been reviewed for Proprietary, SBU, and Export Control (ITAR/EAR) and has been determined to be non-sensitive. It has been released to the public via the NASA Scientific and Technical Information (STI) Process DAA# 20250004573.
Motivation Upfront communication and clarity in key standards and requirements that control hazards will improve Flight Safety and Mission Success, save time, and reduce cost overall Uncovering issues late with propulsion systems are a flight safety risk and costly Need to incorporate lessons learned in rationale to explain why a particular requirement is important
Public Use Permitted
Overview of the Gap Assessment Process
4.3.1 1-FT to Catastrophic Events
4.3.1.1 Primary Struct and Pressure Vessels exempt to 1 FT if follow Approved Standards..
4.3.7 Isolate and Recover from Faults
4.3.8 Facilitate anomaly resolution during and after the mission.
NASA-STD-8719.29 NASA Technical Requirements for Human-Rating
NASA, Military, Industry Standards, And Previous Program Requirements* Note: Many requirements are placed into program requirements (Shuttle, ISS, CCP) over the life of the program and do not exist in other standards.
S = Standard Requirement Exists but needs to be Type 2 in whole or in part SC = Standard Exists but needs Clarification for human rating or Augmentation G = Gaps in Standards
JSC-67723
Map to Hazards/Failure Modes Lessons Learned
Lessons Learned Hazard Controls
Gaps Publicly Available
Incorporate NASA’s Lesson Learned and Technical Bulletins Gathered inputs and review comments from many engineers at GRC, MSFC, JSC, etc over the last couple of years Read NASA STI Reports on Lessons Learned Public reports written by the responsible engineers across all centers and industry Includes AIAA, etc NASA Public Lessons Learned System inputs from all centers Public NESC Technical Bulletins and Reports
Scope of Human Rated Spacecraft Propulsion Standard Address Existing and New Spacecraft Propellants Hydrazine Hypergolic Liquid Bipropellant (MMH/NTO) Gaseous Oxygen, Gaseous Methane , Gaseous Hydrogen , Hydrogen Peroxide / Kerosene Cryogenics; such as Lox, LCH4, LH2 Other propellants that are in work also have a path I.e., Green propellants New Capabilities or configurations Integrated High Thrust Liquid Abort systems and engines Pump-fed systems Exceptions to scope of document Does Not Include Electric Propulsion Thruster, however Xenon fluid system would be encompassed by requirements Does not include cryocooler requirements
Table 1 Human-Rated Spacecraft with Flight History
Note: HTV, ATV & Cygnus meet ISS safety req’ts for interfacing with a human rated spacecraft These are examples of human-rated spacecraft prop systems that form the basis of collective NASA/industry experience
JSC 67723 Human Rated Spacecraft Propulsion Standard
Most of the JSC-67723 requirements are margins, inspections, fault detection capability, or test requirements that address a cause for catastrophic hazard The word “shall” is used as it is derived from the need to control catastrophic hazards In many cases we elevate guideline document that say “should” to “shall” The words “in best practice” or “should” may appear in the Guidance/Rationale “Shall”s are contained in the JSC-67723 document with the intent that this is a Type 2 document or requirement Type 2 = “shall” standard or requirement Type 3 = “reference or guideline” Tailoring Tailoring of this NASA Technical Standard for application to a specific program or project shall be formally documented as part of program or project requirements and approved by the responsible Technical Authority in accordance with NPR 7120.5, NASA Space Flight Program and Project Management Requirements.
A Tailoring Matrix in Excel Format will be provided If document is levied as a Type 3, then “shalls” become “should in best practice”, except for those requirements specifically called out as Type 2 or in program requirement documents.
Alternate Standard or Design Approach In some situations, an alternate or design approach may satisfy the intent of the JSC-67723 requirement for controlling the hazard JSC-67723 is not intended to eliminate design approaches that meet the intent Verification of the alternate requirement or design approach shall include test or inspection
Industry Review This review process is intended to gather industry as well as additional NASA feedback
Purpose of the Industry TIM is to get some specific feedback on individual requirements
Type 2 Standards called out by JSC-67723
Type 2 Standards called out by JSC-67723 (cont.)
Type 3 Reference Guidelines
Example Requirements – Identifying Gaps and Lessons Learned
S = Standard Exists but needs to be Type 2 in whole or in part SC = Standard Exists but needs Clarification or Augmentation G = Gaps in the Standard or Requirement
S = Existing Standard SC = Clarification to Existing Standard G = Requirement that address a gap in an Existing Standard Lesson Learned Links
Appendix A: Tailoring Matrix
3.1 Vehicle-to-Propulsion
3.2 Propulsion System & Component Testing
(SMC-S-016)
3.3 Pressurant and Propellants
3.4 M&P , Fluid Compatibility
3.5 General Pressurized (MDP)
3.6 Pressure Vessels and Propellant Tanks
3.7 Pressure Relief and Regulation
3.8 General Valve Requirements
3.9 Propellant Feed system
3.10 Mechanical Fittings and Flanges
3.11 In-space Fluid Transfer and Modules
3.12 Filters and Filtration
3.13 Pyrotechnic Valves
3.14 TWFPB
3.15 Spacecraft Engines
3.16 Software, FDIR, Instrumentation/Data
3.17 Electrical
3.18 Flight and Ground Interface
3.1.1 Vehicle Performance
3.1.2 Critical Math Models
3.1.3 Reusable Prop Systems
3.1.4 Redundancy Fault Tolerance
3.1.5 Fault Tolerance Exceptions DFMR
3.1.6 Protection of Redundant Functions
3.1.7 GNC to Thruster
3.1.8 Plume Impingement
3.1.9 Slosh
3.1.10 Differential Draining, C.G.
3.1.10 Load and Dynamics
3.1.12 POGO – Thrust/Structural
3.1.13 Thermal
3.1.14 Vents
3.1.15 Problem Resolution
3.2.1 General Tests
3.2.2 System Qual
3.2.3 System development tests
3.2.4 Propulsion System Acceptance, AI&T
3.2.5 Leakage Measurement
3.4.1 M&P NASA-STD-6016
3.4.2 Assembly, Cleaning Fluids
3.4.3 Material Compatibility and Tests
3.4.4 Oxidizer Compatibility Assessments
3.4.5 Softgoods
3.4.6 Contamination Control
3.4.7 FOD, Air, Moisture Intrusion Control
3.4.8 Welding and Bimetallic Joints
3.5.1 MDP
3.5.2 Fracture
3.5.3 NDE
3.5.4 Threaded Fasteners
3.3.1 General Fluid Proc and Usage
3.3.2 Interface, Sampling
3.3.3 Pressurants, Cold Gas
3.3.4 Monopropellants,
3.3.5 Monopropellant hazards
3.3.6 Bipropellants
3.3.7 Earth Storable hazards
3.3.8 Cryogenic hazards
3.3.9 Fluid Property Traceability
3.6.1 Integrated Pressure vessels
3.6.2 Metallic Pressure Vessels
3.6.3 COPV
3.6.4 Composite with plastic liner
3.6.5 Type V all composite
3.6.6 Liiquid PMD
3.6.7 Slosh
3.6.8 Gauging and Un-usables
3.7.1 Pressure Reg System
3.7.2 Overpressure Protection
3.7.3 Reactive Vapors
3.8.1 General (5017, etc)
3.8.2 Tolerance stackup analysis
3.8.3 Torque/Force Margin Tests
3.8.4 Cycle Life
3.8.5 Valve electrical
3.9.1 Engine Interface
3.9.2 Feed-system Activation
3.9.3 Feedsystem MDP
3.9.4 Feed system model V&V
3.9.5 Inhibits to Bulk Prop Leakage
3.9.6 Backpressure Relief
3.9.7 Fluid Line Materials, Routing, etc
3.10.1 Use of Fitting vs. Weld
3.10.2 1FT Design, Qual, Acceptance
3.11.1 In-Space Transfer
3.11.2 Separation of Spacecraft
3.12.1 Identification of Sources
3.12.2 Sensitivity to Contamination
3.12.3 Filter Locations
3.12.4 Filter Spec, Qual, ATP
3.12.5 Alternate to Wire Cloth/Etched Disc
3.13.1 Type NC vs NO requirements
3.13.2 General and Propulsion Specific Requirements
3.14.1 TWFPB Failure Modes
3.14.2 TWFPB JSC-67035
3.14.3 Flow Induced Vibration
3.15.1 Heritage Evaluation
3.15.2 Strength and Life - 5012
3.15.3 Reusable Engines
3.15.4 Test Requirements SMC-S-025
3.15.5 Delta-Qualification
3.15.6 Combustion Stability
3.15.7 Thermal Management
3.15.8 Ignition Systems
3.15.9 Control of Hardstarts, Zots, etc
3.15.10 Engine Leak Detection
3.15.11 TVC
3.16.1 FDIR
3.16.2 Data Rates
3.16.3 System Leak Detection
3.16.4 Instrumentation Types
3.17.1 Electrical Bonding
3.17.2 Powered Device Switching
3.18.1 Time and Cycle Tracking
3.18.2 Data Needs for Flight Ops
3.18.2 Flight to Ground Interface
3.18.3 Hardware Warnings/Markings
Public Use Permitted JSC 67723 Spacecraft Propulsion System Standard
3.1.1 Vehicle and Performance Models
| [PSR-01G] = Specify mission critical propulsion system critical performance parameters |
| [PSR-02S] = Specify Environments SLS-SPEC-159 |
3.1.2 Critical Math Models
| [PSR-03S] = Critical models must meet NASA-STD 7009 |
| [PSR-04G] = Define which propulsion system models are critical models; Performance, Maximum Design Pressure, Thermal Model, GNC and Thruster Math model |
3.1.3 Reusable Vehicle
| [PSR-05SC] = Qualification for repeated inflight and turnaround exposures (ref SMC-S-016 Section 3.4) |
| [PSR-06S] = JSC080802B G-1, G-52, - Accessibility, Time/Cycle Critical Controls, Reuse of flight hardware |
| [PSR-07G] = Operations and Maintenance Requirements and Specification Document |
3.1.4 Redundancy and Fault Tolerance
| [PSR-08S] = NASA-STD-8719.29, NASA Technical Requirements for Human Rating (1 FT) |
| [PSR-09G] = Identify 2nd failures needed to cause catastrophic hazard. |
| [PSR-10S] = JSC80802B G-8 Design for Redundancy Verification |
3.1.5 Failure Tolerance Exceptions (aka DFMR)
[PSR-11SC] = Section 4.3 of NASA-STD-8719.29, NASA Tech. Req. for Human Rating
3.1.6 Separation or Protection of Redundant Functions
[PSR-12S] = JSC080802b – G-2 Separation of Redundant Functions
3.1.7 GNC to Propulsion
| [PSR-13G] = GNC Attitude Control and Thruster Performance and Service Life requirements definition |
| [PSR-14G] = GNC Delta-V Engine (DVE) requirements definition (includes integrated Spacecraft liquid abort engines now) |
| [PSR-15G] = Evaluation of Engine Options at SDR against GNC requirements |
3.1.8 Plume Impingement Loads, Dynamics, Heating, and Contamination
| [PSR-16S] = JSC65829 LD22,66,67,68, 69 Plume Impingement Loads and Dynamics |
| [PSR-17G] = shall be analyzed, designed, tested, and operated to ensure that project/program-defined limits for the deposition of residue |
| [PSR-18G] = shall evaluate plume heating of sensitive surfaces |
| [PSR-19G] = shall evaluate plume impingement and ingestion into sensitive areas (ie parachute cavities, doghouses) |
3.1.9 Slosh Coupling
| [PSR-20SC] = JSC65829 Section 6.6 Slosh Coupling + Impact on liquid acquisition, gauging |
| [PSR-21G] = GNC Control Slosh Requirement such Angular Momentum or Damping |
| [PSR-22G] = Slosh Feature to damp coupled slosh/swirl in vehicles with multiple tanks |
3.1 Vehicle-to-Propulsion
3.1.7 GNC-to-Propulsion
Delta V and RCS Engine Trades:
1) Gimbaled Delta-V engine
2) Off-pulsing/Throttling DVE
3) RCS control of fixed DVE
4) RCS maneuvering and control Trade drives RCS Duty Cycle, Min/Max EPW, Profile Duration, Thrust level, etc Need these defined to select engine and identify design/qual test gaps
Apollo 11 SM retrograded towards CM after jettison due to slosh (ref 3.1.9-1) Apollo 11 LEM slosh caused gage to be inaccurate while landing (ref 3.1.9-2)
3.1.9 Slosh Coupling
3.1.10 Propellant Draining and Center of Gravity Impacts
[PSR-23G] = Track shift in CG for series tanks and control differential draining
3.1.11 Load and Dynamics
| [PSR-24S] = JSC 65829 in its entirety |
| [PSR-25G] = Thrust Overshoot Quantification |
| [PSR-26G] = Vehicle loads and deflection on propulsion system lines and supports |
3.1.12 Unstable Dynamic Coupling of Engine/Thruster, Feed System, and Vehicle Structure (POGO)
| [PSR-27S] = JSC-65829 LD93, 94 |
| [PSR-28,29S] = SMC-S-025 6.4.4, 7.3.7, structure, engine compliance pump & pressure fed. Note High thrust liquid abort systems on spacecraft |
3.1.13 Thermal
| [PSR-30G] = Thermal models to establish min/max temp limits not exceeded |
| [PSR-31S] = Thermal Model meet NASA-STD-7009 & validated with test data |
| [PSR-32S] = SMC-S-016 3.62 and 4.4.2 for thermal uncertainty margins |
| [PSR-33G] = Hardware and Fluids thermally controlled within ATP min max test |
| [PSR-34SC] = SMC-S-016 Qual and ATP Tables 6.3-1, 6.32, Section 6.3.8, 6.3.9, 7.3-1, 7.3-2, 7.3.7, Tables 8.3-, 8.3-2, Section 8.3.7, 8.3.8 |
| [PSR-35SC] = >3 C (5 F) Margin above freezing point of propellant in addition to the uncertainty and power margins |
| [PSR-36G] = >28 C (50 F) margin against auto decomposition temperatures in addition to the thermal uncertainty |
| [PSR-37G] = Thruster inlet propellant margin, relative to qualified operating box, minimum of 11C for passive or a power margin of 25% |
| [PSR-38G] = Maintain gas pressurization systems 11 C above vapor condensation dew point |
| [PSR-39G] = Active and Passive thermal control shall be 1 FT against failure of the passive system (MLI, tape etc are not DFMR items) |
| [PSR-40G] = Test data for thermal parameters (e.g. emissivity, contact resistance) |
| [PSR-41SC] = Active cooling single string margin of 100% at initial design and 25% after flight or TVAC tests. Augment SMC-S-016 4.4.2.2.1 |
3.1.14 Vents
| [PSR-42S] = JSC080802B F-1 with added provision vent flow restriction pressure in included in the cavity pressure (MDP) |
| [PSR-43G] = Venting shall be non-propulsive or net zero torque, unless intended (ie for settling propellant) |
| [PSR-44G] = Propellant vents or leakage shall be evaluated for hazards such as compatibility with surrounding materials and cabin ingestion |
| [PSR-45G]= shall be evaluated for freezing of the vented commodity that may block the vent or for other hazards. |
3.1.15 Anomaly, Issues, Problem Tracking and Resolution
[PSR-46SC] = JSC080802B G-15, Resolution of Flight Equipment Failures/Anomalies Prior to Launch augmented to include heritage hardware past failures
3.1 Vehicle-to-Propulsion
Public Use Permitted
Apollo 15 CM RCS dump of raw fuel caused burning and damaged of riser Ref 3.1.14-1
Crew exposed to 750 ppm N2O4 due to entry sequence error firing thrusters with isolation valve closed during cabin repress. Pilot became unconscious.
Ref 3.1.14-2
Boeing CST-100 Starliner Pad Abort Test | NASA Image and Video Library
3.2.1 General Test Requirements
| [PSR-47S] = SMC-S-016 in its entirety with the following augmentation |
| [PSR-48G] = Perform Leaks tests before, during, and after vibration, shock, and thermal cycle, qualification and acceptance. |
| [PSR-49G] = Perform heritage qual gap assessment per Aerospace Report Number TOR-2013(3909)-1, Objective Reuse of Heritage Products |
| [PSR-50G] = Trending of ATP data and out of family identification |
| [PSR-51G] = Planetary surface dust testing |
3.2.2 System Level Qualification Tests
[PSR-52G] = System Level Hotfire Qualification Test with detailed requirements for high hardware fidelity and mission duty cycle profile testing Test scope in accordance with the requirements of section 8.0 in SMC-S-025 Use of flight-representative fluid commodities.
Use of flight-representative fluid components. (includes the flight instrumentation) Use of flight-representative fluid lines.
Use of flight-representative engines/thrusters and pod/cluster configurations.
Use of flight-representative thrust vector control (TVC) actuators and electronic controllers Use of flight-representative electrical power sources and valve driver avionics.
Use of equivalent passive and active thermal control elements for temperature conditioning of the engine/thruster hardware and the propellants Use of flight-representative servicing/deservicing and ground turnaround interfaces and procedures for the liquid and gaseous fluid commodities capability to fully saturate the liquid propellants with pressurant gas at all pressure/temperature conditions included in the test matrix Perform hot fire sequences at vacuum (altitude) conditions and variable backpressure for entry vehicle applications Mission profiles that encompass EPWs, DC%, and profile duration content to demonstrate all nominal and contingency transient dynamic events in the pre-launch and in-flight concept of operations exposure of the hardware to all relevant external environments that could drive adverse interactions with the loaded propellants structural coupling and thrust dynamics evaluation to verify no unstable coupling of the mounting structure and liquid-propulsion system Includes content for engine/thruster chug and combustion stability evaluation per the requirements of JANNAF-GL-2022-0001 Combustion Stability Spec Utilizes a development instrumentation system needed to provide qualification data, as a supplement to the onboard flight instruments Utilizes a structured test readiness review (TRR) process to finalize all test plans and test procedures, document TLYF exceptions
3.2 Propulsion System/Component Testing & SMC-S-016
Public Use Permitted System Level Hot-fire with Mission Duty Cycle Profile with Environments is a Critical Test
1998 Mars Polar Lander Failure, Post flight System Hot-fire Test Bed uncovered valve failure mechanism, Replicated only during system level hot-fire Ref 3.2.2-1
3.2.2 System Level Qualification Tests (cont.)
[PSR-53SC] = Complete propulsion system qualification prior to first uncrewed test flight
3.2.3 System level development tests
[PSR-54G] = Conduct engine and system level development tests to determine acceptability prior to CDR
3.2.4 Propulsion System and Component Acceptance, AI&T
| [PSR-55SC] = Acceptance test at minimum and maximum predicted temperature extremes, ie use LH2 (SMC-S-016 only says to consider this) |
| [PSR-56G] = Perform acceptance hot-fire test of engine assembly (SMC-S-016 does not require this explicitly) |
| [PSR-57SC] = Perform end-to-end gas flow test to check for blockages, JSC-08080 F20 |
| [PSR-58S] = JSC 8080 2B G-3 Electrical and Fluid System Checkout |
| [PSR-59SC] = Perform Cryogenic propulsion system tanking tests and hot-fire acceptance testing |
| [PSR-60G] = Perform Hydrogen Peroxide propulsion system propellant loading and tanking down to thrusters for acceptance |
3.2.5 Leakage Measurement
| [PSR-61G] = Propulsion System Allowable leak rate determination |
| [PSR-62SC] = Use NASA-STD-7012 for leak measurement methods including supplementary provisions. Note: 7012 only says pick one. |
| [PSR-63G] = Specify that propulsion system shall be tested using 1) system level total decay, 2) local measurement, 3) spacecraft real-time leak check |
| [PSR-64G] = Specify that individual / local measurements shall use LTR 15 Method II accumulation (ie mass spec of joint wrapped in bag) |
| [PSR-65SC] = Special considerations for leak checking bellows and flexhoses using LTR 15 |
3.2 Propulsion System/Component Testing & SMC-S-016
System Blockage Tests for Hypers, Green Run for Cryogenics, Global and Local Leak Tests Public Use Permitted Ref 11-1
LH2 Leaks caused launch delays on 6 flights.
Real-time leak detection Ref 3.2.5-2
SSC20210116_GR9312 | NASA Image and Video Library SLS Core Stage Green Run (Ref 3.2.5-1)
3.3 Propellant and Fluids Procurement and Usage, Hazards
3.3.1 General Fluid Procurement and Usage Requirements
| [PSR-66G] = Procurement and usage spec of a propellant shall be utilized and controlled for the propulsion system; if none exists then one shall be created |
| [PSR-67G] = Manufacturing process change for propellants requires compliance verification and demonstration test with engine testing |
| [PSR-68G] = Propellant storage systems shall have specification for materials, soluble contamination, moisture, particulate, duration, pressure, temperature, saturation, |
| [PSR-69G] = Documentation of formal training for designers and operators in the use and hazards for all propellants and a formal process to identify hazards |
3.3.2 General Fluid Interface, Sampling
| [PSR-70G] = GSE filtered at the propulsion system interface to prevent particulate larger than the minimum size associated with the specified precision cleanliness level | |
| [PSR-71S] = Sampling of Fluids per JSC 8080-2 F-27 | |
| [PSR-72G] = Sampling of ground storage vessel periodically prior to each spacecraft loading event and prior to refilling - concentration of other gases or contaminates | (weathering) |
| [PSR-73G] = Sampling at the interface to the vehicle – check out GSE plumbing |
3.3.3 Pressurants, Cold Gas
| [PSR-74S] = Helium per MIL-PRF-27407 Type 1 Either grade A or B provide all qual tests and flight are done with the same fluid |
| [PSR-75S] = Nitrogen per MIL-PRF-27401 Grade B or C, (not A due to moisture and O2) |
| [PSR-76G] = inert gas hazards – asphyxiation , low temps, overpress of spacecraft compartments |
Public Use Permitted
Cryo Testing at ML, Pad 39B | NASA Image and Video Library
Spacecraft fueling technicians from Kennedy Space Center take a sample of the monomethylhydrazine propellant KSC-2010-1055 | NASA Image and Video Library
3.3.4 Monopropellants (including some that are used in bipropellant systems)
| [PSR-77S] = Hydrazine per High Purity Hydrazine (HPH) per MIL-PRF-26536 |
| [PSR-78S] = HPH assessed for contaminates not controlled in specification; NESC Technical Bulletin 22-08, |
| [PSR-79S] = Hydrogen Peroxide per MIL-PRF-16005. NASA/TM-2005-213151 |
| [PSR-80S] = Nitrous Oxide CGA G-8.2 QVL-A, Commodity Specification for Nitrous Oxide – Seventh Edition |
3.3.5 Monopropellant Hazards
| [PSR-81G] = Establish Component worst case temperature cause by environment and failures | |
| [PSR-82G] = Maximum Allowable Hydrazine temperature of 160 deg F for valves and engine head end components (meeting NASA-STD-6016 and NASA-STD-6001) | |
| [PSR-83G] = If engine valve and headend components wetted with hydrazine exceed 160 deg F, then additional testing is required | |
| [PSR-84G] = Monopropellant shall be screened for variables that impact auto-decomposition temperatures (saturation, pressurization rates, heating rates, contaminations) | |
| [PSR-85S] = JSC-8080-2F-6 Temperature and Pressure Monitoring Requirements for Potentially Hazardous Reactive Fluids | |
| [PSR-86S] = AIAA SP-084-1999, Fire, Explosion, Compatibility, and Safety Hazards of Hypergols – Hydrazine | |
| [PSR-87G] = Nitrous Oxide application shall be evaluated for hazards observed as reported in Scaled Composites N2O Safety Guidelines 6.17.09.doc, AFRL-RZ-ED-TP-2008-184 | |
| [PSR-88S] = Hydrogen Peroxide systems shall be evaluated for hazards per NASA HYDROGEN PEROXIDE PROPELLANT HAZARDS TECHNICAL MANUAL. | |
| [PSR-89G] = Hydrogen peroxide systems shall follow documented and proven/verified contamination control and inspection requirements | |
| [PSR-90G] = The occurrence of cavitation shall be evaluated and avoided in hydrogen peroxide systems. Reference NESC Technical Bulletin 21-01, | |
| [PSR-91G] = Evaluation of the increased catalytic effect of materials of construction on decomposition of hydrazine, and other monopropellants at maximum predicted temp | |
| [PSR-92G] = Evaluate adiabatic / rapid compression detonation of monopropellants with presence of decomposition gases or pressurant gas bubbles (N2H4, H2O2, N2O) | |
| [PSR-93G] = Throat plugs for engines/thrusters using monopropellant hydrazine shall have a flow through purge to prevent to reduce carbon dioxide exposure at the air interface | |
| 3.3 | Propellant and Fluids Procurement and Usage, Hazards |
Human Spacecraft are being developed with many different propellants or new usage, Need to Understand Hazards
Ref 3.3.5-2
KSC-2014-4771 | NASA Image and Video Library
KSC-MA9-174 | NASA Image and Video Library
3.3 Propellant and Fluids Procurement and Usage Specification
3.3.5 Bipropellants
| [PSR-94S] = MIL-PRF-25508, Performance Specification, Propellant, Oxygen |
| [PSR-95S] = MIL-PRF-27201, Performance Specification, Propellant, Hydrogen |
| [PSR-96SC] = MIL-PRF-26539, Performance Specification Propellants, Dinitrogen Tetroxide, Clarify water content below 0.05% and iron content below 0.1 ppmw |
| [PSR-97G] = Nitric Oxide (NO) content greater than 1% must be maintained during all operations of the propulsion system (NO will vaporize off ) |
| [PSR-98S] = MIL-PRF-27404, Performance Specification Propellant, Monomethylhydrazine |
| [PSR-99S] = MIL-PRF-32207, Performance Specification, Propellant, Methane. (includes procurement as LNG) |
| [PSR-100S] = MIL-DTL-25576, Detail Specification Propellant, Rocket Grade Kerosene |
3.3.6 Bipropellant Hypergolic MMH/NTO hazards
| [PSR-101S] = AIAA SP-086-2001 (NTO), “Fire, Explosion, Compatibility, and Safety Hazards of Nitrogen Tetroxide.” and AIAA SP-085-1999 “…Hazards of Hypergols MMH” | |
| [PSR-102G] = shall implement and maintain at all time a dry low dewpoint verified purge at all dynamic and environmental seals and openings | |
| [PSR-103G] = Throat plugs shall have a flow through purge to prevent NTO/MON3 propellants from reacting at wetted fuel seat and to reduce moisture exposure at ox | seat |
| [PSR-104G] = Teflon flexhoses are not allowed in spacecraft system due to permeation of propellants |
3.3.7 Cryogenic hazards
| [PSR-105S] = Oxygen Safety Standards ASTM G88-21 is called out by NASA-STD-6016 for material flammability | |
| JSC has a cryo safety manual, as well as other centers. JPR 1700.1M-Chpt 6.4 | |
| [PSR-106S] = ANSI/AIAA G-095A-2017, Guide to Safety of Hydrogen and Hydrogen Systems [also called out by NASA-STD-6016] | |
| [PSR-107G] = Evaluate hazards due to boil-off that will increase concentration of other hydrocarbons and residuals | |
| [PSR-108G] = Evaluate hazards due to any sub-cooling below normal point of the cryogens (air liquefaction, etc) | |
| [PSR-109G] = Evaluate boiling liquid evaporative explosion (BLEVE) | |
| [PSR-110G] = Low dewpoint purge and monitor dewpoint to prevent ice formation and plugging |
3.3.8 Propellant Properties
| [PSR-111G] = Use propellant properties traceable to NIST |
| [PSR-112G] = If properties do not exist, use NIST methodology and/or processes to obtain or estimate |
There are some unique hazards with each propellant
Ref 3.3.6-1
3.4 Materials and Processes (M&P) and Fluid Compatibility
3.4.1 M&P NASA-STD-6016
| [PSR-113S] = NASA-STD-6016 STANDARD MATERIALS AND PROCESSES REQUIREMENTS FOR SPACECRAFT |
| [PSR-114G] = GSE must also meet NASA-STD-6016 |
3.4.2 Test and Assembly Fluids; Cleaning, Flushing, and Drying
| [PSR-115SC] = DI Water shall meet the requirements of ASTM D1193, Type I (any grade) or Type II (any grade), shall include ‘monitoring’ content of Appendix X1.3 |
| [PSR-116S] = IPA per TT-I-735 Grade A, with the final rinse and sampling using reagent grade or better. |
| [PSR-117S] = CGA G-11.1, Commodity Specification for Argon, Quality Verification Level (QVL) C, D, E, or F, or MIL-PRF-27415,, Argon, Grade A or B |
| [PSR-118S] = HFE per A-A-59150 [ Work is occurring to find a substitute] |
| [PSR-119S] = Leak Detection Fluid per MIL-PRF-25567 |
| [PSR-120G] = Assess compatibility of cleaning fluids with propulsion system materials and fluids |
| [PSR-121G] = shall perform verification of dryness at component level during acceptance testing and at integrated propulsion system level after cleaning/flushing |
3.4.3 Material Compatibility and Tests
| [PSR-122G] = Qualification of systems and components shall include full duration exposure tests to propellants, environment, and other relevant fluids (not just coupon tests) |
| [PSR-123G] = Fluid and manufacturing tooling material compatibility (ie, internal tube bending tooling, etc) |
| [PSR-124G] = NTO applications should limit the use of CRES |
| [PSR-125G] = Failure of sensor diaphragm and Material compatibility |
3.4.4 Propellant Oxidizer and Material Ignition and Combustion [PSR-126SC] = NASA-STD-6016C 4.2.1.4 (Oxygen Compatibility) or 4.2.1.3 (Fluid Compatibility, Fluids Other Than Oxygen) with additional clarifications
3.4.5 Softgoods
| [PSR-127S] = Shall assess soft good properties change with propellant and cleaning fluid exposure at temp, and pressure (swell, permeation, strength, etc), S.L. duration |
| [PSR-128G] = Cleaning fluids must be specific to propellant intended under use |
| [PSR-129G] = Swapping ox and fuel components after cleaning or exposure to propellants is not allowed. Require full disassembly and softgood replacement |
Common-cause failures of multiple thrusters in flight Corrosion due NTO + DI Water w/Chlorides, Soft good swell
Shuttle STS-9 APU 1 Explosion Ref 3.4.3-1
3.4 Materials and Processes (M&P) and Fluid Compatibility
3.4.6 Propulsion System Cleaning
| [PSR-130S] = NASA STD-6016 Sections 4.2.6.7 and 4.2.6.8 (also Meets JSC 8080 F-17 and F-19) |
| [PSR-131SC] = IEST-STD-CC1246 with added provision that no particles larger than maximum |
| [PSR-132G] = Final Cleanliness Verification of components with liquid (e.g. HFE, IPA) and component vacuum dried |
| [PSR-133SC] = Spacecraft assembly at Class 8 per ISO 14644-1 (note equiv. to Class 100,000 per FED-STD-209E) |
| [PSR-134G] = lines designed to be capable of final verification of cleanliness and after R&R (flush, borescope, xray) |
| [PSR-135G] = Feedline capable of being removed for cleaning after any trim to fit prior to welding |
| [PSR-136G] = Surveillance on Tube segments and welded assemblies with borescope inspection and sampling |
| [PSR-137G] = For tubing where borescope inspection is not possible, then process demonstration can use next size up |
| [PSR-138G] = Precision cleaning of the borescope used for internal inspections |
| [PSR-139G] = Verified tube cutting process and tool maintenance |
| [PSR-140G] = Protecting against system contamination during tube preparation |
| [PSR-141G] = verification by 1) inert gas flow process demonstrated to move particles, 2) internal borescope, 3) x-ray |
| [PSR-142G] = TWFPB need a specific process developed and verified. |
| [PSR-143G] = Flexhose Cleaning |
3.4.7 External FOD Control
| [PSR-144S] = JSC 8080-2b and NAS412 FOD prevention |
| [PSR-145S] = JSC 8080-2B G4 FOD protection |
| [PSR-146G] = Features to prevent 1) leaving it in-place inadvertently, 2) dropping into the plumbing, or 3) shedding pieces |
| [PSR-147G] = Locking feature on GSE threaded fasteners interfacing with flight hardware openings |
| [PSR-148G] = Periodic inspections and closeout photos to insure no loose parts or FOD |
| [PSR-149G] = Dry purge or Seal against moisture-laden air intrusion |
| PSR-150G] = Ingestion of water into the propulsion system and engine chambers |
3.4.8 Welding and Bimetallic Joints
| [PSR-151S] = Welds per NASA STD 6016 Class A | |
| [PSR-152G] = Clarify MIL-STD1252, Bimetallic Inertial Welds or transition joints shall have lot testing and acceptance | using first and last SEM examined for brittle intermetallic |
Contamination found by Borescope after tubing Verified Clean Metal Particles seen in X-ray
Brittle Bi-metallic Joints
Hydrazine Thruster Valve Leak MSL Descent Stage
Ref 3.4.8-1
3.5 Propulsion System Pressurized Hardware
3.5.1 MDP
| [PSR-153S] = JSC 65828 STR0022 Pressure regulators, relief devices and thermal control systems (e.g.heaters) shall collectively be two-fault tolerant to exceeding MDP |
| [PSR-154SC] = MDP shall include relief system setpoint. Exception to JSC-65828 3.2.8.3 STR0021 which allows MDP exceedance by 10% during relief of pressure |
| [PSR-155G] = NASA/TM-20210022275, Treatment of Transient Pressure Events in Space Flight Pressurized Systems |
3.5.2 Fracture
[PSR-156S] = NASA-STD-5019 Rev A w/ Change 2, Fracture Control Requirements for Spaceflight Hardware
3.5.3 NDE
[PSR-157S] = NASA-STD-5009 Rev A, Nondestructive Evaluation Requirements for Fracture-Critical Metallic Components
3.5.4 Threaded Fasteners
[PSR-158S] = NASA-STD-5020 Rev A, Requirements for Threaded Fastening Systems in Spaceflight Hardware
Treatment of Transient Pressure Events (Pressure Spikes) Needs Clarification Maximum Design Pressure (MDP):
The Maximum Design Pressure (MDP) for a pressurized system is the highest pressure defined by the maximum relief pressure, maximum regulator pressure, maximum temperature and transient pressure excursions based on two credible system failures.
Public Use Permitted Ref 3.5.1-1
3.6 Pressure Vessels and Propellant Tanks
3.6.1 Integrated Propellant Tanks
[PSR-159G] = full tank assembly level(Pressure Vessel + PMD + Lines + Supports) analysis and test requirements for structural integrity and material compatibility
3.6.2 Type I Metallic Pressure Vessels
| [PSR-160S] = JSC 65828, including paragraph 3.2.8.4 [STR0022] governing Metallic Pressurized Hardware |
| [PSR-161SC] = Clarify 1.25 proof/1.5 Burst tank can meet JSC-65828 , with NDE, and disallow proof pressure as sole means of flaw screening. |
| [PSR-162S] = NASA-STD-5009 NDE |
| [PSR-163G] = POD of 90/95 that accounts for double-wall radiography of metallic pressure vessels. NESC Technical Bulletin 19-02 |
| [PSR-164G] = Aspect ratios at A/C=1.0 and A/C=0.2 shall each be evaluated. |
3.6.3 Type II and III COPV
| [PSR-165S] = JSC 65828, including paragraph 3.2.8.5 [STR0023] governing Composite Overwrapped Pressure Vessels (COPVs). |
| [PSR-166SC] = Models shall be correlated to the qualification tank per JSC-65828 STR066, STR0067, STR0068, STR0070. |
| [PSR-167G] = Bond line sensitivity studies shall be performed for tanks . NASA NESC Technical Bulletin No.20-07 |
| [PSR-168G] = POD of 90/95 that accounts for double-wall radiography of metallic liners tank welds. |
| [PSR-169S] = NDE methods in NASA-STD-5009 shall be followed |
| [PSR-170G] = Aspect ratios at A/C=1.0 and A/C=0.2 shall each be evaluated |
Additional pressure vessel NDE requirements and integrated tank are required
Public Use Permitted Ref 3.6.3
3.6 Pressure Vessels and Propellant Tanks
3.6.4 Type IV Composite with plastic liner
| [PSR-171G] = JSC ES 151001-1 “Use of ASME Code or CFR 49 (DOT)Pressure Vessels | |
| [PSR-172SC] = AIAA-G-082: 2022 - Guide: Space Systems - Composite Overwrapped Pressure Vessels With A Plastic Liner. Not Sufficient by itself for human | spaceflight |
| [PSR-172aG] = Tank design and qualification standards shall be reviewed by NASA appointed SME. | |
| [PSR-172bG] = Tests of mission representative duration if reactive media can penetrate the overwrap either by permeation or submersion | |
| [PSR-172cG] = Composite compatible with all fluids contacting it thru permeation, without detrimental deformation, leakage, or rupture | |
| [PSR-172dG] = Controls shall be listed for the raw materials used to make the liner | |
| [PSR-172eG] = Assessment for damage tolerance | |
| [PSR-172fG] = Statistical basis for material properties is required for all materials including the liner material | |
| [PSR-172gG] = External pressure conditions need to be examined for conditions of vacuum filling, purge, applied external pressure and buckling | |
| [PSR-172hG] = determine credible sources of mechanical damage to the COPV. These credible sources will be provided in the Damage Control Plan(DCP) | |
| [PSR-172iG] = Unique ascent and space operating environments shall be examined more closely for Type IV CPV with plastic liner. | |
| [PSR-172jG] = designed to sustain the negative pressure differential without detrimental deformation, detrimental leakage, or rupture | |
| [PSR-172kG] = Examination of full saturation when assessing for permeation shall be performed. | |
| [PSR-172lG] = credible flaws/indications are identified through an assessment the credible range of sizes/shapes/depths and shall direct the NDT capabilities |
3.6.5 Type V all composite
[PSR-173G] = No standard exists for Type V. Need to develop one.
3.6 Pressure Vessels and Propellant Tanks
3.6.6 Liquid PMD
| [PSR-174G] = PMD in a liquid propellant tank shall provide gas-free liquid to the propellant feed lines during engine/thruster operation under acceleration levels per GNC |
| [PSR-175G] = surface tension screen galleries in a liquid propellant tank, a minimum safety factor of 2.0 for bubble point |
| [PSR-176G] = surface tension vanes in a liquid propellant tank, minimum safety factors of 3.0 on friction/flow losses and 2.0 on surface tension |
| [PSR-177G] = sponges in a liquid propellant tank, a minimum safety factor of 2.0 for the deliverable volume vs. the demand volume shall be maintained |
| [PSR-178SC] = Positive expulsion thin wall flexible metallic bellows or diaphragms shall meet the fracture control requirements or TWFPB JSC 67035 |
| [PSR-179G] = Positive expulsion elastomeric and metallic design shall include assessment of the material compatibility and permeation of propellant vapors |
| [PSR-180G] = Diaphragm delta pressure limits |
| [PSR-181G] = PMD, attached to the pressure vessel wall as part of the propellant tank assembly, shall be qualification tested… |
| [PSR-182G] = Performance testing of the integrated propellant tank assembly as part of unit qualification and acceptance per SMC-S-016 |
3.6.7 Slosh Damping Device
| [PSR-183G] = slosh damping devices within a propellant tank shall be designed to mitigate swirl motion (single and multi-tank), vortex, and lateral motion |
| [PSR-184G] = Performance of the slosh damping devices within a propellant tank shall be demonstrated through a combination of analysis and test |
| [PSR-185G] = Slosh features shall meet structural margins and test requirements |
3.6.9 Gauging and Un-usables
| [PSR-186G] = design of a spacecraft propulsion system shall incorporate a method of propellant quantity gauging to address the inadvertent depletion |
| [PSR-187G] = if burn time integration is only gauging method, a separate means of detecting external/overboard propellant leakage and off-nominal engine perf. |
| [PSR-188G] = Any uncertainty or error associated with the propellant gauging method shall be considered as unusable commodity |
| [PSR-189G] = Performance verification of the propellant quantity gauging method shall be accomplished via testing, a 3-sigma Monte Carlo analysis |
| [PSR-190G] = Any uncertainty associated with the propellant loaded into the propulsion system during pre-launch ground operations shall be considered as unusable |
Ref 3.6.6 Ref 3.6.6
3.7 Pressurization Subsystem
3.7.1 Pressure Reg System (Series and Parallel configuration of iso valves, regulator/valve, filter, check valves)
| [PSR-191G] = shall specify outlet pressure range as a function of flowrate and inlet pressure in the system |
| [PSR-192G] = shall be dynamically stable with a return to stable operation, no sustained organized oscillations |
| [PSR-193G] = shall be tested for slam start transients to measure overshoot when the system is activated |
| [PSR-194G] = overshoot pressure upon termination of flow shall remain below the hardware MDP and RV setpoint |
| [PSR-195G] = overshoot pressure shall account for liquid that may in zero-g be located in the pressurization system lines |
| [PSR-196G] = fault tolerance shall include failures in the electronic control, such as pressure sensing |
| [PSR-197G] = each serial or parallel stage in a redundant configuration shall be tested in qual and acceptance |
| [PSR-198G] = each serial or parallel stage in a redundant configuration shall be tested in qual and acceptance |
3.7.2 Overpressure Protection
| [PSR-199G] = shall Provide full flow relief at 100% of the system MDP (note JSC -65828 STR-0021 is 110%) |
| [PSR-200G] = shall perform Pressure relief device performance testing per F-18 JSC-08080-2 |
| [PSR-201G] = relief device, vent line location, and vent line sizing shall consider the migration or presence of liquid propellant into vent line |
| [PSR-202G] = a positive (i.e. non-permeable) vapor barrier (e.g., burst disk) upstream shall be included in the design to prevent corrosion and ice |
3.7.3 Reactive Vapors
| [PSR-203S] = ‘separation of hypergolic reactants’ requirements of paragraph F-15 in JSC-08080-2 | |
| [PSR-204SC] = Check valves, valves, elastomerics, and tank liquid retention devices are not barriers to vapor migration | |
| [PSR-205G] = shall control of condensation of propellant vapors in pressurization system | |
| [PSR-206G] = Use of common pressurization restricted to short term use (with prior pyro isolation) and proven with | exposure tests of 4x duration |
| [PSR-207G] = Propellant tank pressurization port liquid retention device is required if design not shown to be tolerant of liquid in pressurization system |
Catastrophic Hazards Include Loss of Helium (Prop Function), Rupture due to Mixing of Ox and fuel
Loss of Mars Observer occurred upon system pressurization for Mars Orbit insertion burn Mars Observer (MO) was a satellite propulsion system designed for an early mission apogee burn, but was repurposed for planetary missions MO Loss was due to either Regulator Fail Open- NTO Corrosion*, Regulator leakage due to Contamination, Reaction of Ox and Fuel, Pyro valve failure (expulsion of NSI) *Regulator Fail Open NTO Corrosion is most likely: Filter/screen used AMS 4774 Braze material that was not compatible with NTO and was not called out on drawings for review. Corrosion was dislodged during pyro firing and plugged regulator sense orifice.
Ref 3.7.3 Guernsey, C. S., 2001, "Propulsion lessons learned from the loss of Mars Observer", https://hdl.handle.net/2014/36825, ['37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference', 'Salt Lake City, UT, USA'], JPL Open Repository; 01-1441.pdf
Shuttle MPS Helium Pressurization Panel experienced regulator instability causing fail open, RV popping open during activation, check valve chatter, isolation valve bellows failure, etc Ref 3.7.1-1
3.8 Propulsion System Valves
3.8.1 General Requirements for Valves
| [PSR-208S] Valves shall meet all requirements in NASA-STD-5017 |
| [PSR-209G] Reserved for future NASA standard on valves |
3.8.2 Dimensional Analysis and Clearances
[PSR-210G] Include effects of propellant exposure in NASA-STD 5017 4.1.2
3.8.3 Torque/Force Margin Analysis
| [PSR-211SC] Valve torque and force margin analysis account for pressure transients, avionics/wiring, in NASA STD-5017 4.3.3.1 DDMR9 (missing) |
| [PSR-212SC] Include effects of propellant exposure and soft good swell/permeation in NASA STD-5017 4.3.3.1 DDMR9 (missing) |
3.8.4 Cycle Life
| [PSR-213SC] Include wet and dry ground cycles in cycle life – clarify 4.19.3.2 DDMR75 NASA-STD-5017 |
| [PSR-214SC] Cycle life shall be based on fault cases and 3 sigma GNC Monte Carlo simulations – augment 4.19.3.2 [DDMR75] of NASA-STD-5017 |
| [PSR-215G] factor of 4x on the specified cycle-life of the unit, spread across the full range of applicable operating conditions for the hardware |
3.8.5 Valve Electrical
| [PSR-216S] shall comply with the requirements of NASA-STD-8739.10, Electrical, Electronic, And Electromechanical (EEE) Parts Assurance Standard |
| [PSR-217S] shall comply with the requirements of EMI/EMC for space systems per MIL-STD-461G |
Contamination, Incorrect Materials for Propellant Exposure & Environment, Not Accounting for how Operated, Insufficient Qualification, Acceptance Testing, Quality Control, etc
Shuttle MPS LH2 Prevalve Actuator Ground checkout cycling damaged seat thus causing leaks Added Anti-slam valves onto actuator Ref 3.8.4-1
Ref 3.8.3-1
3.9 Propellant Feed System
3.9.1 Propellant Feed System and Engine Interface Conditions
| [PSR-218G] Propellant Feed system designed to meet engine interface limits for pressure, temperature, gas bubbles, over mission profiles per GNC, # engines |
| [PSR-219G] Integrated dynamic analysis of system and engine chamber pressures (water hammer, slumps, overpressures) over tank pressure, temps, gas sat. |
| [PSR-220G] Pressure slump in feed system shall maintain 1.25 margin over propellant vapor pressure to avoid bubble collapse dynamics ACD, Seat damage, etc |
| [PSR-221G] Assume all dissolved gases come out of solution thru pressure drops (NESC Tech Bulletin 22-07) |
3.9.2 Propellant Feed System Activation; Priming and Repriming
| [PSR-222G] concept of operations for the propellant feed system activation shall be determined at SDR |
| [PSR-223G] redundant instrumentation to monitor pressure shall be provided in each isolated manifold to ensure non-hazardous priming |
| [PSR-224G] priming/repriming analysis shall encompass the worst-case pressure, propellant quality, propellant vapor and non-condensable gas bubble size |
3.9.3 Propellant Feed System Maximum Design Pressure Transients
| [PSR-225G] determination of MDP values for the hardware shall include all water-hammer or surge transient conditions and events of any duration |
| [PSR-226G] dynamic amplification factor shall follow NASA/TM-20210022275, Treatment of Transient Pressure Events in Space Flight Pressurized Systems |
3.9.4 Feed System Model Verification and Validation
| [PSR-227G] breadboard/prototype system level test, including wetted propellant lines, shall be conducted by PDR |
| [PSR-228G] feed system analysis, that is anchored to test data using referee fluids and/or actual propellants, shall be conducted by PDR |
| [PSR-229G] feed system model per NASA-STD-7009, Standard for Models and Simulations, and be maintained/updated in the critical math model database |
3.9.5 Propellant Isolation – Inhibits to Bulk Propellant Loss
| [PSR-230G] shall provide a minimum of three (3) independently verifiable mechanical inhibits to the leakage/release of bulk propellant prior to activation |
| [PSR-231G] shall provide a minimum of two (2) inhibits to the leakage/release of bulk propellant through the intended propellant flow path(s) during operation |
| [PSR-232G] Mechanical joints shall provide a minimum of two (2) independently verifiable mechanical inhibits to the leakage/release of bulk propellant |
| [PSR-233G] Propellant service valves shall provide three (3) mechanical inhibits to the release of bulk propellant, minimum of one (1) independently verifiable |
3.9.6 Feed system back pressure relief
[PSR-234G] Sections of tubing where propellants may be trapped (e.g. hydraulically locked) shall include redundant pressure relief provisions (e.g. back-relief)
3.9.7 Fluid Line Design, Routing and Installation
| [PSR-235G] Detailed drawings and CAD shall be provided for design routing and installation procedures of all fluid lines in the propulsion system |
| [PSR-236 G]fluid line design and analysis shall consider vacuum and gravitational effects, ranging from 1-g to zero-g, |
Feed system water-hammer and surge pressure are major source of failures and hazard such as ACD Public Use Permitted
Apollo LM Breadboard/Prototype system uncovered issues with thruster inlet dropping to vapor pressure resulting in zero thrust, transient pressure exceeding proof pressure Ref 3.9-1
3.10 General Requirements for Mechanical Fittings, Joints and Flanges
3.10.1 Use of Mechanical Fittings/Joints vs. Brazing or Welding [PSR-237G] use of separable mechanical fluid fittings/joints shall be limited to the situations outlined in paragraph MS-15 of JSC-08080
3.10.2 Mechanical Fitting, Joint, and Flange Design, Qualification, & Acceptance
| [PSR-238G] Mechanical fittings, such as K-seals and Dynatubes, joints, and flanges shall ,meet following design, qualification, and acceptance requirements | |
| [PSR-238a] = D: shall contain at least two seals or sealing surfaces in the design | |
| [PSR-238b] = D: shall be verified capable of independently performing the intended sealing function | |
| [PSR-238c] = D: shall have a verifiable positive restraint to preclude loss of seal load | |
| [PSR-238d] = Q: Certification data, when required, shall be summarized by the provider | |
| [PSR-238e] = Q: Test data showing that each individual seal is capable of independently performing the intended sealing function | |
| [PSR-238f] = Q: Vibration qualification test data, subsequent leak tests, to qualify the fitting/joint design for the predicted ground and flight vibration | |
| [PSR-238g] = Q: Thermal cycle qualification test data, subsequent leak tests, and supporting analysis shall be used for the predicted thermal cycles | |
| [PSR-238h] = Q: Pressure cycle qualification test data, subsequent leak tests, and supporting analysis shall be used to qualify the fitting/joint design | |
| [PSR-238i] = Q: Test showing proof, burst, yield and ultimate combined load safety factors of the fittings/joints shall meet JSC 65828 | |
| [PSR-238j] = Q: Analysis, procedures, and test data qualifying the leak rate of the fluid fittings/joints up to MDP | |
| [PSR-238k] = Q: Engagement/disengagement cycle test data to qualify the fitting for the predicted processing cycle life shall for four times (4x) | |
| [PSR-238l] = Q: Compatibility data for fitting/joint materials for the fluid and environmental exposure conditions and durations shall be provided | |
| [PSR-238m] = Q: Test data shall show the ability of the fitting/joint design to meet leakage requirements given dispersions in assembly parameters | |
| [PSR-238n] = Q: include assembly procedures, manufacturing, mis-alignment, under and over-torque, thread relaxation, line loading, supports | |
| [PSR-238o] = Q: Seal savers, if used to repair a leaking joint, shall be qualified and accepted with the same requirements | |
| [PSR-238p] = A: parts shall be of design materials | |
| [PSR-238q] = A: parts meet drawing requirements for surface finish, flatness, tolerances, mechanical features | |
| [PSR-238r] = A: parts shall be proof tested at 1.5MDP, inclusive of each independent seal in flanged joint. | |
| [PSR-238s] = A: Parts shall be cleaned and verified per the drawing or system requirements | |
| [PSR-238t] = A: parts shall be assembled with designated observer (MIP) to verify workmanship, photograph, no FOD, no scratches, | |
| [PSR-238u] = A: torque check operation shall have 24 hours between first torque and final torque check | |
| [PSR-238v] = A: Parts shall be leak tested at 1.0xMDP after final mating, inclusive of each independent seal in a flange joint |
Requirements for Mechanical Fittings and Joints was only in program documentation (ie CCP)
Skylab 2 Dynatube Leak Ref 3.10.2-1 Ref 3.10.2-2
3.11 Fluid Transfer Couplings (FTC) and Fluid Transfer Systems (FTS)
3.11.1 In-Flight Refueling Couplings
| [PSR-239S] AIAA-S-157 “In Space Storable Fluid Transfer for Prepared Spacecraft” shall be used for requirements that control catastrophic hazards |
| [PSR-240SC] FTS shall incorporate 3 barriers against external leakage with the fluid coupling demated or mated and with isolation valves as a barrier |
| [PSR-241SC] FTC shall include 1 FT sealing features that are in place prior to or during the engagement or disengagement of poppets |
| [PSR-242G] FTC shall incorporate filter elements installed immediately upstream and then at some point downstream |
| [PSR-243G] FTC shall have caps or covers that can remain installed on the flight and ground halves individually when not mated, |
| [PSR-244G] FTC shall undergo leak checks of the coupling unmated or mated, prior to and during in-flight fluid transfer operations |
| [PSR-245G] FTS shall have isolation valves upstream and downstream of the FTC that are used for starting/stopping fluid flow (do not use coupling mate/demate) |
3.11.2 Separation of Spacecraft Modules
| [PSR-246S] shall follow ‘fluid lines separation’ requirements of paragraph F-5 in JSC-08080-2, JSC Design and Procedural Standards |
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