There are satellite that use the STT system almost entirely independently of all other systems. Particularly ones that need to remain in a certain orientation for 100% of their service life, such as geostationary telecom and weather satellites that orbit along the equator and are always aimed towards the visible hemisphere of earth. On those, the directional hemisphere and spot beam antennas are fixed in place (or can only move a few degrees motion at best, such as Ku band spot beam antennas), relying on the body orientation of the satellite to service a certain area of the visible hemisphere.
Satellites are designed to go into "safe mode" if certain fault protection events happen, or the multiply redundant control systems/onboard computers don't agree with each other. Safe mode usually means shutting down all nonessential electrical loads and trying to orient themselves so that solar panels receive the greatest amount of charge, while listening for command and control data on their omni (L and S band) TT&C antennas.
With this event it sounds like something REALLY went wrong since not only did the satellite try to correct a nonexistant wrong orientation via its reaction wheels (reaction wheels are not nearly as powerful in real life as they are in kerbal space program), it then decided to start expending propellant and spun itself up to such a RPM of revolutions that it tore off its own solar panels, and anything else that would be vulnerable to high centrifugal G forces. Automated code that expends propellant is usually checked much more carefully than this, since the amount of propellant is fixed and non renewable, usually the primary constraint on the total service life of the satellite. Most satellites run out of stationkeeping/orientation propellant (or propellant for ion engine delta-V changes) long before their multiply redundant solar/charge controller/battery/computer control systems fail.
Satellites are designed to go into "safe mode" if certain fault protection events happen, or the multiply redundant control systems/onboard computers don't agree with each other. Safe mode usually means shutting down all nonessential electrical loads and trying to orient themselves so that solar panels receive the greatest amount of charge, while listening for command and control data on their omni (L and S band) TT&C antennas.
With this event it sounds like something REALLY went wrong since not only did the satellite try to correct a nonexistant wrong orientation via its reaction wheels (reaction wheels are not nearly as powerful in real life as they are in kerbal space program), it then decided to start expending propellant and spun itself up to such a RPM of revolutions that it tore off its own solar panels, and anything else that would be vulnerable to high centrifugal G forces. Automated code that expends propellant is usually checked much more carefully than this, since the amount of propellant is fixed and non renewable, usually the primary constraint on the total service life of the satellite. Most satellites run out of stationkeeping/orientation propellant (or propellant for ion engine delta-V changes) long before their multiply redundant solar/charge controller/battery/computer control systems fail.