Page 242 - NAVAL SCIENCE 3 TEXTBOOK

248 NAVAL SKILLS

Guided Missile Trajectories lvlissile trajectories include many shapes or types of CllIyes.
The exact nature of the curve is determined by the type of guid-
The Imjee/or)' of a missile is its p<lth ti'OIll lauIlch to impact or
allce and the nature of the control system used, A hyperbolic tra-
destruct. There arc two basic types of missile tnljectories: ballis-
jectory, for instance, will occur with a missile lIsing a hyperbolic
tic and aerodynamic. A number of other trajectories are named
guidallCe system. The missile ",ill first climb to the desired altitude,
according to the p<lth tr~l\'eled. such as glide, pO\\'ered flight, termi-
then follow an arc of a hyperbola before diving on its target.
nal, and standard, among others.
A pursuit curve is followed by most homing and beam rider
In a ballistic trajectory, the missile is acted upon only by gr,w-
missiles. At an)' given instant, the missile is pointed directly toward
it)' ilnd aerodynamic drag after the propulsive force is terminated.
the target. If sllch a missile pursues a crossing target, the missile
Gun projectiles have a purely ballistic trajectory. The major part of
must follow a curved trajcctoq'. In some cases, the extreme cur-
the trajectory of ballistic missiles is of this type. An C1eroriY'/{/lI/ic
vature required by the pursuit course as the missile nears the tar-
tmjectory is one in which aerodynamic forces (thrust, drag, weight,
get may be too sharp lor the missile to follow. In this case, <l highly
and lift) are used to Illaintain the flight path.
maneu\'erablc aircraft with <l proficient pilot may be sllccessful in
LINE OF SIGHT (LOS,,>

,
TARGET FLIGHT P
\ r o
\ J" SHARP
\ CURVATURE CAUSES
\ <0 HIGH
\ '" ACCELERATIONS
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\ \_----MISSILE FLIGHT PATH
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The pursuit homing or zero-bearing missile intercept path followed by most homing and beam rider missiles.