20b respectively which also effectively seals chamber 18 for a period of several milliseconds to thereby accomplish projectile flight path correction as the pressure in chamber 18 in fig5 dissipates within the several millisecond period the resilient means 30 described above causes the rear end 13 to return to its original position shown in fig4 with its longitudinal axis coaxial with front end 9 electro optical and sensing portion 10 may thereafter fire another gas cartridge for further projectile course correction in fig5 vanes such as 19a and 19b or 20a and 20b are shown as pairs of vanes as mentioned previously this is required for the proper functioning of my invention for the example given gas cartridge 17 was fired expanding chamber 18 and vanes 15 and 15a expanded up against vanes 19a and 20b respectively however provision must be made for firing others of the gas cartridges in the event gas cartridge 17a is fired vanes 15 and 15b need vanes 19b and 21b respectively to expand against similarly firing of gas cartridge 17b causes chamber 18b to expand and and vanes 15a and 15c move against vanes 20a and 29b respectively without pairs of vanes this operation is not possible in fig6 is shown the optical view 22 seen by the projectile in the terminal phase of its flight when it 34 sees 34 the laser designated target 27 the optical view is broken up into six sections corresponding to the previously described chambers created in rear end 13 of the projectile each section has a number of bands although only three bands 24 25 and 26 are representatively shown in fig6 when target 27 is.