Put everything in the UW orbital FMEA Spreadsheet as well (https://docs.google.com/spreadsheets/d/1HXKbXskj5TnBeDjVg0VAIt9JYc2V_OU_VXXN9zo_Tto/edit#gid=589520811)

https://drive.google.com/file/d/1y10zV6jmWYmp0U_AIgdWFCLCG26iBUiD/view

https://sites.google.com/site/manitobasat1/subsystems/aodcs?authuser=0

Steps:

  1. FMEA Pre-Work and Assemble the FMEA Team
    1. Having easy access to the EPS Block Diagram would be useful - where on earth is it? It doesn't appear to be in the wiki for some reason

Severity Scale

Rating Effect Description
5 Very Bad Catastrophic, imminent mission failure
4 Major Serious permanent capacity damage
3 Moderate Potential permanent damage
2 Minor Temporary, difficult to correct error
1 Low Temporary, easily correctable error

Occurrence Scale

Rating Effect Failure Rate
5 Lots Once a minute or less
4 Frequent Hourly
3 Sometimes Daily
2 Occasional Weekly
1 Very rare Could happen once a mission

Detection Scale

Rating Effect Description
5 No chance that it will be detected
4
3
2
1 Easily detectable, features planned or in place to find such an error

Failure Modes

Failure Function Severity Rating Detection Rating Occurrence Rating Mitigation
Battery failure Charge/Discharge issues (MPPT circuit fails, etc.) 10
Battery failure Insufficient charge capacity due to battery degradation 8 3
Battery failure Mechanical failure (disconnection, etc.) 3
Battery failure Launch killswitch fails to disengage 10 1 1
MPPT failure MPPT failure 7
MPPT failure Diode O-ring circuit failure 8
Battery heater failure Battery 8 3
Solar Panel failure Not getting enough sunlight because of poor orientation 7 3
Solar panel failure Solar panels degrade 8 2
Power control/regulation EPS MCU failure
Power control/regulation CDH MCU failure 9
Power control/regulation Thermal circuit degradation
Power control/regulation Mechanical circuit degradation (wire comes loose, solder failure, PC104 header failure) 8 3 Lots of quality control
Power control/regulation Power converter failure (DC-DC, buck-boost converters 7
Power control/regulation Power regulator failure (incorrect voltage on rails) 7
Power control/regulation Power amplifier failure
Power control/regulation ESD issues
Power control/regulation/distribution Radiation shielding failure
Power control/regulation Power transfer failure (wires)
Power control/regulation Short/Open circuit
Power distribution Protection circuit failure
Power distribution Load switch circuit failure
Power distribution CDH-EPS communication failure (no data)
Voltage spikes Single upset events
General Circuit Degradation Total Ionizing Dose 6