Editing Missile (section)

===Guidance, targeting and flight systems===
{{main|Missile guidance}}
[[File:Missile homing.jpg|thumb|200px|A semi-active missile [[Homing (missile guidance)|homing]] system]]
A missile is most often guided by a guidance system though there are missiles that are unguided during some phases of flight.<ref name="Siouris">{{Cite book|title=Missile Guidance and Control Systems|first=George|last=Siouris|year=2006|isbn=978-0-3872-1816-8|publisher=[[Springer New York]]|page=6}}</ref> Missile guidance refers to methods of guiding a missile to its intended target. Effective guidance is important because reaching the target position accurately and precisely is a critical factor for its effectiveness.<ref>{{Cite book|url=https://books.google.com/books?id=wjVnisG_6KMC&q=Probability+of+guidance&pg=PA34|title=Fundamentals of Strategic Weapons: Offense and Defense Systems|isbn=978-9-0247-2545-8|last1=Constant|first1=James N.|date=27 September 1981|publisher=[[Brill Publishers|Martinus Nijhoff Publishers]] }}</ref> The missile guidance system accomplishes this by four steps: tracking the target, computing the directions using tracking information, directing the computed inputs to steering control and steering the missile by directing inputs to motors or flight control surfaces.<ref name="USO">{{Cite book|title=Aviation Ordnanceman 3 & 2|page=355|year=1967|publisher=United States Bureau of Naval Personnel}}</ref> The guidance system consists of three sections: launch, mid-course and terminal with same or different systems employed across sections.<ref name="USO"/>
[[File:Solid-Fuel Rocket Diagram.svg|thumb|200px|A simplified diagram of a solid-fuel rocket. {{olist
  |A [[Rocket propellant|propellant]] is packed with a hole in the middle
  |An [[Pyrotechnic initiator|igniter]] combusts the propellant
  |The hole acts as a [[combustion chamber]]
  |The hot exhaust is choked at the throat
  |Exhaust exits the rocket
}}]]

The guidance and [[Homing (missile guidance)|homing]] systems are generally classified broadly into [[Active radar homing|active]], [[Semi-active radar homing|semi-active]] and [[Passive radar homing|passive]].<ref name="Siouris"/> In active homing systems, the missile carries the equipment needed to transmit the radiation needed to illuminate the target and receive the reflected energy. Once the homing is initiated, the missile [[fire-and-forget|directs independently]] towards the target.<ref>{{Cite book|title=Weapons System Fundamentals: Synthesis of systems|page=60|year=1960|publisher=[[United States Government Printing Office]]}}</ref> In semi-active systems, the source of the radiation is located outside the missile usually in the launch vehicle which might be an aircraft or a ship and the missile will receive the radiation to direct towards the target. As the source is located outside, the launch vehicle needs to continue supporting the missile till it is guided to the intended target.<ref name="Ctr">{{Cite book|title=Fire Control Technician M 3 & 2|publisher=[[United States Navy|United States Naval Education and Training Command]]|year=1978|page=87}}</ref> In a passive system, the missile relies solely on the information from the target.<ref name="Ctr"/> The homing system might use [[light]] such as [[infrared homing|infrared]], [[laser guidance|laser]] or [[visible light]], [[radar guidance|radio wave]]s or other [[electromagnetic radiation]] to illuminate the target. Once the guidance system identifies the target, the target might required to be tracked continuously if it is in motion. A guidance system might use [[Inertial navigation system|INS]] which consists of a [[gyroscope]] and [[accelerometer]] or might use  [[satellite guidance]] (such as [[Global Positioning System|GPS]]) to track the missile’s position relative to a known target.<ref>{{Cite encyclopedia|url=https://www.britannica.com/technology/inertial-guidance-system|title=Inertial Guidance System|encyclopedia=[[Britannica]]|access-date=1 December 2023}}</ref> The missile computers will compute the flight path required to steer the missile towards the target.<ref name="Ctr" /> In [[command guidance]], a human operator may operate it manually or a support or launch system will transmit commands by using either [[optic fiber]] or [[radio-control|radio]] to guide the missile.<ref>{{Cite encyclopedia|url=https://www.britannica.com/technology/command-guidance-system|title=Command Guidance System|encyclopedia=[[Britannica]]|access-date=1 December 2023}}</ref> The flight system uses the data from the targeting or guidance system to maneuver the missile in flight which might be accomplished using [[thrust vectoring|vectored thrust]] of engines or aerodynamic maneuvering using [[flight control surface]]s such as [[airplane wing|wings]], fins and [[canard (aeronautics)|canards]].<ref>{{Cite web|url=https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/vectored-thrust/|title=Vectored thrust|work=[[NASA]]|access-date=1 December 2023}}</ref>