SCIAMACHY Life Limited Item (LLI) Tracking
have an in-flight switches/cycles budget which must not be exceeded.
|switches/cycles||burning time (hr)|
|NDFM||49000a / 98000b||n/a|
|APSM||49000a / 98000b||n/a|
|Cryo Heatpipe||22c / 40d||n/a|
a) with safety factor (margin) 2 (no longer applicable)
b) without safety factor
c) with high safety factor 3 (no longer applicable)
d) with safety factor 2
In support of the operational LLI tracking, SOST-IMF performs a LLI 'prediction' by estimating the LLI activations based on the planned timelines. As long as the actual operations do not differ from the planned operations, LLI estimate and operationally tracked LLI usage shall be identical. The LLI prediction can be found on the LLI status page. Note that the prediction includes the non-LLI entries 'ASM diffuser exposure' and 'ESM diffuser exposure'. It was found useful to accumulate a record of the diffuser exposure times during the mission lifetime.
For the Cryo Heatpipe item, LLI tracking is performed via recording execution of decontamination.