{HEAD ~ The spring} thus duplicates the force pulse acting on a fired projectile and also allows for {TAIL ~ the drop vehicle} to be reused 
allows for
{ HEAD ~ The spring } thus duplicates the force pulse acting on a fired projectile and also allows for { TAIL ~ the drop vehicle } to be reused
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH