| 4.4.8-4-1 Ensure subsystem design including units, assemblies, sub-assemblies and parts meets the mission performance requirements |
Phase A |
Phase B |
Phase C |
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Pre-Phase A, as applicable, ensure the design satisfies the requirements under the conditions specified by the Design Reference Mission. There should be a realistic worst-case scenario to show that the requirements can be met with margin. Phase A onward, the derived CONOPS should be in a particular document (Flight Requirements and Ops documents) or operations working group products. Some mission concepts may not be directly translated to subsystem requirements in terms of the overall mission operability. The subsystem must be validated against how the components will be used for that particular application.
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NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494; Mission Assurance Guide, TOR-2007(8546)-6018, Rev B
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| 4.4.8-4-2 Ensure trade studies were conducted and the design baseline satisfies mission requirements and the analysis of alternatives has identified the baseline as the best value |
Phase A |
Phase B |
Phase C |
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Ensure that all trade studies are realizable in terms of technology used and conform to system requirement and physical constraints. Check that viable candidates received appropriate consideration.
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NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494
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| 4.4.8-4-3 Ensure subsystem technology readiness and risk burn-down plan have been assessed |
Phase A |
Phase B |
Phase C |
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Ensure subsystem technologies, including manufacturing, supplier readiness and programmatic readiness, are mature enough to support the development timeline. Check that the risk mitigation plans are sufficient, funded and conclude at the right time.
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NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494
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| 4.4.8-4-4 Ensure subsystem hardware and software (as applicable) functions are described in the subsystem specification |
Phase A |
Phase B |
Phase C |
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Ensure that descriptive functions for subsystems and units (including software) are detailed enough for new personnel to understand how the unit or subsystem behaves both individually and within the system.
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NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494
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| 4.4.8-4-5 Ensure subsystem hardware and software (as applicable) is identified as heritage, modified, or new |
Phase B |
Phase C |
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Ensure heritage qualification adequacy is documented by analysis and test.
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NA
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NA
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Objective Criteria for Heritage Hardware Reuse, TOR-2010(8591)-19; Reuse of Hardware and Software Products, TOR-2009(8546)-8604
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| 4.4.8-4-6 Ensure all defined contract deliverables and relevant contractor data are complete and accurate to support design reviews |
Phase A |
Phase B |
Phase C |
|
Ensure all relevant data is readily available and delivered to support design reviews and design forums.
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NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494
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| 4.4.8-4-7 Ensure subsystem layout has been provided to include plumbing, thrusters, tanks, panels, etc. |
Phase B |
Phase C |
|
NA
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NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494
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| 4.4.8-4-8 Ensure assembly, integration, and test are accommodated in design |
Phase B |
Phase C |
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NA
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NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494
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| 4.4.8-4-9 Ensure EMC requirements are addressed and a control plan is generated |
Phase B |
Phase C |
|
Ensure that MA EMC spec are flowed down and that the EMC control plan is generated for the subsystem with emphasis on EMC design and verification at the lowest level of build. Ensure EMC issues are identified and have appropriate mitigation plans.
|
NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494
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| 4.4.8-4-10 Ensure proper tank design (sizing, structural, thermal, etc) |
Phase B |
Phase C |
|
Ensure that worst case environments and operation have been accounted for and the margin against capacity is appropriate for the program's phase. Tank shells are long-lead parts and so qualification tasks often need to be performed early in a program.
|
NA
|
NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494; American Institute of Aeronautics and Astronautics, Space Systems-Metallic Pressure Vessels, Pressurized Structures, and Pressure Components, American National Standard, ANSI / AIAA S-080-1998; American Institute of Aeronautics and Astronautics, Space Systems-Composite Overwrapped Pressure Vessels (COPVs), American National Standard, ANSI / AIAA S-081A-2006
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| 4.4.8-4-11 Ensure proper tank propellant management system for all phases and modes |
Phase B |
Phase C |
|
NA
|
NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494
|
| 4.4.8-4-12 Ensure that the thruster design satisfies the requirements and CONOPs including thruster sizing, lifetime throughput and duty cycle, maximum on-time, thermal conditions, etc. |
Phase B |
Phase C |
|
The thruster design must be assessed against the mission need to ensure that the design is appropriate and is likely to pass qualification / acceptance testing.
|
NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494; Spacecraft Pressure-Fed, Hypergolic Bipropellant Propulsion Systems Lessons Learned, ATM-2015-01236; Problem History for Low-Thrust Monopropellant Hydrazine Thrusters, ATM-2015-03173
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| 4.4.8-4-13 Ensure that all plumbing components such as regulators, valves, propellant lines, etc are appropriate for the PS design |
Phase B |
Phase C |
|
Component designs should comply with derived requirements and CONOPS. Interactions between components should be considered, particularly with respect to failure tolerance. Issues of material compatibility and operating pressures/temperatures are particularly important for propulsion systems.
|
NA
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NA
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Space Vehicle Systems Engineering Handbook, TOR-2006(8506)-4494; Design and Test Requirements for Space Flight Pressurized Systems, TR-RS-2015-00005; Space Systems-Metallic Pressure Vessels, Pressurized Structures, and Pressure Components, ANSI / AIAA S-080-1998
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| 4.4.8-4-14 Ensure that any potentially systemic design issues are considered for a Design Advisory |
Phase B |
Phase C |
Phase D1 |
Phase D2 |
Phase D3 |
|
Any design or architecture issue that has severe, systemic, or widespread consequences is a potential candidate for a Design Advisory. Design Advisories provide the community with timely and interim notification of an important design issue which may ultimately be captured in a specification or standard.
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NA
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NA
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NA
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