Goa'uld recall device
Device incorporated into Apophis's death gliders following Teal'c's first rebellion on planet Chulak. Before this time, such a device had not been necessary. Upon the launch of a death glider there are several moments which pass before the recall device takes control of all flight operations, directing the craft to Apophis' home world.
This message then resounds from Apophis himself: "Shol'vah! To all those who would turn against their god, know this. For your insolence you will die in the cold of space. What is rightfully mine will now return to me!"
Samantha Carter believed there would be a safety to prevent any tampering with the recall device which would result in more immediate consequences. Depending on the ship's location in space, the glider could potentially take many hundreds of years to arrive at Apophis' original home planet.
It is possible the recall device lies in the memory of other ships Apophis controlled, such as Tel'taks and troop transports.
Tangent - Test flying the X-301 interceptor, Teal'c and O'Neill are sent into deep space on course through the Ort cloud nebula which will lead to Apophis' original home planet.
Fail Safe - Carter is still concerned after she tells her teammates she has found no signs of a recall device from Yu's downed Tel'tak.