AFSS meaning in Space Science ?

In the field of rocketry, range safety may be assured by a system which is intended to protect people and assets on both the rocket range and downrange in cases when a launch vehicle might endanger them. For a rocket deemed to be off course, range safety may be implemented by something as simple as commanding the rocket to shut down the propulsion system or by something as sophisticated as an independent Flight Termination System (FTS), which has redundant transceivers in the launch vehicle that can receive a command to self-destruct then set off charges in the launch vehicle to combust the rocket propellants at altitude. Not all national space programs use flight termination systems on launch vehicles.

Range safety officers or RSOs are also present in the hobby of model rocketry and then are usually responsible for ensuring a rocket is built correctly, using a safe engine/recovery device, and launched correctly.