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IC and Component Selection for Space Sy stems – Presented by Kenneth A . LaBel 9 Risk Requirements • Rationale – T rying to ensure mission parameters such as reliability , availability , operate-through, and lifetime are…

IC and Component Selection for Space Systems – Presented by Kenneth A. LaBel

Programmatic Requirements and

Considerations

• Rationale

– Trying to keep a program on schedule

and within budget

• Personnel involved

– Project manager, resource analyst,

system scheduler

• Usual method of requirements

– Flowdown from parent organization

or mission goals for budget/schedule

• I.e., Launch date

• Buzzwords

– Cost cap, GANTT/PERT chart, risk

matrix, contingency

• Limiting factors

– Parent organization makes final

decision

Programmatics

A numbers game

IC and Component Selection for Space Systems – Presented by Kenneth A. LaBel

Risk Requirements

• Rationale

– Trying to ensure mission parameters such as reliability,

availability, operate-through, and lifetime are met

• Personnel involved

– Radiation engineer, reliability engineer, parts engineer

• Usual method of requirements

– Flowdown from mission requirements for parameter space

• I.e., SEU rate for system derived from system availability specification

• Buzzwords

– Lifetime, total dose, single events, device screening, “waivers”

• Limiting factors

– Management normally makes “acceptable” risk decision

IC and Component Selection for Space Systems – Presented by Kenneth A. LaBel

An Example “Ad hoc” Battle

• Mission requirement: High resolution image

– Flowdown requirement: 14-bit 100 Msps ADC

• Usually more detailed requirements are used such as

ENOB or INL or DNL as well

– Designer

• Searches for available radiation hardened ADCs that

meet the above requirements

• Searches for commercial alternatives that could be

upscreened

– Manager

• Trades the cost of buying Mil-Aero part requiring less

aftermarket testing than a purely commercial IC

• Worries over delivery and test schedule of the candidate

devices

– Radiation/Parts Engineer

• Evaluates existing device data to determine reliability

performance and additional test cost and schedule

• The best device? Depends on mission priorities