Rockets bending around enemies?

Hello, all. I have a quick fps question. I have these rockets that the player can shoot, but I have the problem that they don't explode on my enemies, they bend around them and continue their path. I can tell they are going around the enemy because I've made a smoke trail and it shows them going around the enemy. the enemy has a sphere collider for a head(for head shots) and a character controller for the main body. The rocket has a simple box collider. Here is the rocket script.

 @script AddComponentMenu("FPS / Weapons / Rockets")
 @script RequireComponent(AudioSource);
 
 var explosionRadius : float;
 var damage : int;
 var power : int;
 var particleEffect : GameObject;
 var sound : AudioClip;
 var lifeTime : float;
 var Speed : float;
 var enemyRocket : boolean = false;
 private var audioSource : AudioSource;
 
 function Awake()
 {        
     var Player : Transform = gameObject.FindWithTag("Player").transform;
     if(enemyRocket)
         transform.LookAt(Player);
     
     audioSource = gameObject.GetComponent(AudioSource);
     Destroy(gameObject, lifeTime);
 }
 function OnCollisionEnter(col : Collision)
 {
     if(col.gameObject.tag != "Enemy")
         Explode();
 }
 function OnTriggerEnter(col : Collider)
 {
     if(col.gameObject.tag != "Enemy")
         Explode();
 }
 function Update ()
 {
     rigidbody.velocity = transform.forward * Speed;    
 }
 function Explode () 
 {
     var explosionPosition : Vector3 = transform.position;
     var colliders : Collider[] = Physics.OverlapSphere (explosionPosition, explosionRadius);
     for(var hit in colliders)
     {
         hit.SendMessageUpwards("ApplyDamage", damage, SendMessageOptions.DontRequireReceiver);
         if(hit.rigidbody)
         {
             hit.rigidbody.AddExplosionForce(power, explosionPosition, explosionRadius, power);
         }
     }
     if(particleEffect)
     {
         var go : GameObject = Instantiate(particleEffect, transform.position, transform.rotation);
     }
     if(sound != null)
     {
         audioSource.PlayClipAtPoint(sound, explosionPosition);
     }
     Destroy(gameObject);
 }