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IC and Component Selection for Space Sy stems – Presented by Kenneth A . LaBel 21 Is T esting Always Required? • Exceptions for testing may include – Operational • Ex., The device is only powered on once per orbit and th…

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

IC’s with no Guarantee or Heritage

• Radiation testing is required in

the vast majority of cases

– Testing complexities and

challenges are discussed

elsewhere (e.g., Swift during this

short course, LaBel during the

conference)

– The true challenge is to gather

sufficient data in a cost and

schedule effective manner.

• A backup plan should be made in

case device fails to pass radiation

criteria.

• Reliability testing has similar

concerns

FPGA-based motherboard

SDRAM mounted on a daughtercard

“Abandon all hope, ye’ who enter here”

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

Is Testing Always Required?

• Exceptions for testing may include

– Operational

• Ex., The device is only powered on once per orbit and the

sensitive time window for a single event effect is minimal

– Acceptable data loss

• Ex., System level error rate may be set such that data is

gathered 95% of the time. This is data availability. Given

physical device volume and assuming every ion causes

an upset, this worst-case rate may be tractable.

– Negligible effect

• Ex., A 2 week mission on a shuttle may have a very low

TID requirement. TID testing could be waived.

A FLASH memory may be acceptable

without testing if a low TID

requirement exists or not powered on

for the large majority of time.

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

Understanding Risk

• Risk for a mission falls in to the same topic areas as parts

selection

– Technical, programmatic, and reliability

• Technical risks

– Relate to the circuit designs not being able to meet mission

criteria such as jitter related to a long dwell time of a telescope

on an object

• Programmatic risks

– Relate to a mission missing a launch window or exceeding a

budgetary cost cap which can lead to mission cancellation

• Reliability risks

– Relate to mission meeting its lifetime and performance goals

without premature failures or unexpected anomalies

• Each mission must determine its priorities among the three

risk types