Range safety
[2] To assist the range safety officer (RSO) in monitoring the launch and making eventual decisions, there are many indicators showing the condition of the space vehicle in flight.
These included booster chamber pressures, vertical plane charts (later supplanted by computer-generated destruct lines), and height and speed indicators.
[2] Throughout the flight, RSOs pay close attention to the instantaneous impact point (IIP) of the launch vehicle, which is constantly updated along with its position; when a rocket is predicted to cross one of the destruct lines in flight because of any reason, a destruct command is issued to prevent the vehicle from endangering people and assets outside of the safety zone.
Previously, the RSO transmitted an 'arm' command just before flight termination, which rendered the FTS usable and shut down the engines of liquid-fueled rockets.
Range safety transmitters operate continuously at very high power levels to ensure a substantial link margin.
The signal levels seen by the range safety receivers are checked before launch and monitored throughout flight to ensure adequate margins.
When the launch vehicle is no longer a threat, the range safety system is typically safed (shut down) to prevent inadvertent activation.
[citation needed] After initial lift-off, flight information is captured with X- and C-band radars, and S-Band telemetry receivers from vehicle-borne transmitters.
[citation needed] At the Eastern Test Range, S and C-Band antennas were located in the Bahamas and as far as the island of Antigua, after which the space vehicle finished its propulsion stages or is in orbit.
The arm switch shut down propulsion for liquid propelled vehicles, and the destruct ignited the primacord surrounding the fuel tanks.
[citation needed] The Cape Canaveral Space Force Station saw around 450 failed launches of missiles and rockets (of around 3400 total) between 1950 and 1998,[8] with an unknown amount of flights ending by intervention of onboard or ground-based safety mechanisms.
[9] For launches from the Eastern Range, which includes Kennedy Space Center and Cape Canaveral Space Force Station, the Mission Flight Control Officer (MFCO) is responsible for ensuring public safety from the vehicle during its flight up to orbital insertion, or, in the event that the launch is of a ballistic type, until all pieces have fallen safely to Earth.
[citation needed] The MFCO is guided in making destruct decisions by as many as three different types of computer display graphics, generated by the flight analysis section of range safety.
This real time footprint was developed in response to the Space Shuttle Challenger disaster in 1986 when stray solid rocket boosters unexpectedly broke off from the destroyed core vehicle and began traveling uprange, toward land.
[citation needed] The U.S. Space Shuttle orbiter did not have destruct devices, but the solid rocket boosters (SRBs) and external tank both did.
[10] After the Space Shuttle Challenger broke up in flight, the RSO ordered the uncontrolled, free-flying SRBs destroyed before they could pose a threat.
During the Soviet era, expended rocket stages or debris from failed launches were thoroughly cleaned up, but since the collapse of the USSR, this practice has lapsed.
[16] From the early 2020s, the China Aerospace Science and Technology Corporation (CASC) started developing and implementing methods to prevent uncontrolled reentries of their Long March rocket boosters, most prominently by the use of parachutes.
On the successful third launch attempt of the rocket, it was reported that officials activated the flight termination system on the first stage after separation, presumably to destroy evidence in an effort to prevent reverse engineering if the booster were to be recovered by South Korea or allies.
[27] As it is the only thing that is able to ensure the safety of ground facilities, personnel and spectators during a rocket launch, it is required to be effectively 100 percent reliable.
[28][29] To prevent other components from interfering with its decisions, the FTS has to operate entirely independently from the rocket; as such, it needs separate maintenance and comes with its own power source.
[26] This is done by detonating high explosives, usually linear shaped charges,[36] in specific areas of the rocket, which initiates structural failure and renders the vehicle aerodynamically unstable.
[45][46][47] Previously, inadvertent separation destruct systems had already been deployed to destroy parts of rockets, usually side boosters, autonomously when they were unintentionally removed or loosened from the remainder of the vehicle.
The 'polar corridor' would involve turning south shortly after liftoff, passing just east of Miami, with a first stage splashdown north of Cuba.
[52] Such a launch corridor is not feasible with a ground-commanded system due to radio interference from the rocket's own exhaust plume facing the ground station.
[55] Upon activation, the explosive ordnance detonated as expected, but destruction was delayed;[56] the vehicle was only destroyed at T+3:59,[36] 40 seconds after the AFTS was estimated to be triggered.
The AFSS onboard Ariane 5 is called KASSAV (Kit Autonome de Sécurité pour la SAuvergarde en Vol).
[60] The SpaceOne KAIROS solid-fuel rocket uses an AFTS;[61] it was activated mere seconds into the vehicle's maiden flight because the speed and thrust of the launcher at liftoff was lower than intended.
