Background:

Since it is not planned to have instrument operational heater zone 7 enabled, the camera is not heated and will maintain it’s own temperature through internal heat dissipation of it’s electronics. The nominal on orbit temperature of the camera electronic will be on the order to 0-5° C (TBC). A survival heater will protect it from going below -7° C. Therefore, if the electronic should overheat, it is likely the result of it’s own heat dissipation. AP#31 will initiate RTS#47 if the electronics temperature reaches 50° C, pausing any active sequence and turning off the camera.

Note: If something has gone awry with the decontamination or operational heaters, AP#27, 28 and RTS#43, 44 will have turned off the heaters prior to the camera electronics temperature reaching 50° C.

ACTIONPOINT logic:

If ( Instrument CCD Electronics Temperature > 50 degrees C

(for 24 or more consecutive samples) ) Execute CAM_TEMP

file: cam_temp.atf

00:00:00 /ICSQPAUS

00:00:00 /ICPWCMOF

Key Telemetry:

‘inst_thermal’

IOINCCDETEMP - CCD Electronics Temperature

Instrument: Camera Electronics High Temperature #1 Sensed

Value #1: The Actionpoint number that failed its limit.

Value #2: The RTS number that was requested.

Value #3: The number of consecutive failures that triggered this Actionpoint

Value #4: Unused.

Recovery Procedure:

1. Notify EOF and S/C OE to begin anomaly investigation

2. Reset AP#31 to ACTIVE (/LCAPSTATE AP=31, ACTIVE)

3. Turn camera power back on with TI_cm_on

4. Resume sequences via ground command (/ICSQRESM) or by timeline

References:

TRACE C&DH FSW User’s Guide

http://tracedata.nascom.nasa.gov/~trace/cdhsw/trace/design/sc/pre_rts.htm