The term 'Missile Heading' can be broken down into two crossword solutions: VECTOR (6 letters) and VIBE (4 letters). VECTOR is a term used in mathematics and physics to describe a quantity that has both magnitude and direction. It is often used to represent the velocity, acceleration, or force of an object. VIBE is a slang term used to describe the atmosphere or feeling of a place or situation. It is often used to describe the overall mood or energy of a group of people. Together, these two terms can be used to describe the direction and atmosphere of a missile heading.