Larry J wrote:
I know on the DSCS-III satellites that I used to control, there was no mechanism for disabling safe mode. I wouldn't be surprised if the same was true for Galileo.

Alex writes:
Yes and no. As you note, safe mode is incorporated for a very good reason. However, for interplanetary spacecraft with significant TWLT values safe mode can be (and is) routinely disabled for mission critical events such as orbital insertion; for example, this happened with MGS. This was no big deal for MGS, as no science data were being collected during this time, and the same holds true for most but not all such spacecraft. Galileo, on the other hand, did collect data (the Probe Relay mission) in the timeframe immediately prior to JOI. In this instance, safe mode was not disabled, though the Project utilized another technique known as critical mode, which does allow for "graceful degradation" to safe mode.

Alex R. Blackwell
University of Hawaii