Command_Loss_Timer_Reset
Command Loss Timer Resets are part of the CCSDS communications system to spacecraft either in Earth orbit or beyond Earth orbit.
The Command Loss Timer Reset, if it is not received in a timely manner by the spacecraft, generally forces the spacecraft to engage in safety and self-protection procedures.
- Command Loss Timer Reset systems involve both hardware and software, whereas watchdog timers are essentially hardware-only affairs.
- Most spacecraft have more than one Command Loss Timer Reset for subsystem level safety reasons, with the Voyager craft using at least 7 of these timers.
- Technically the Command Loss Timer Reset is a glorified array of Watchdog timers, each with different settings.
Overall spacecraft safety is very important for missions of multi-year duration. This means that the Command Loss Timer Reset subsystem has to be used to avoid multiple computer reboot events. Generally speaking, when a computer reboots it decreases the overall safety of the spacecraft for a very brief time.