re command loss timer re galileo update alan carter writes on april a no op command was sent to reset the command loss timer to hours its planned value during this mission phase this activity is regularly reported in ron s interesting posts could someone explain what the command loss timer is the name is rather descriptive it s a command to the spacecraft that tells it if you don t hear from earth after hours assume something is wrong with your the spacecraft attitude and go into a preprogrammed search mode in an attempt to reacquire the signal from earth the spacecraft and earth are not in constant communication with each other earth monitors the telemetry from the spacecraft and if everything is fine there s no reason to send it any new information but from the spacecraft s point of view no information from earth could mean either everything is fine or that the spacecraft has lost signal acquisition just how long should the spacecraft wait before it decides that something is wrong and begins to take corrective action that how long is the command loss timer during relatively inactive cruise phases the command loss timer can be set to rather long values in this case earth is telling galileo expect to hear back from us sometime within the next hours
