Rotating an object according to the way it's moving

I am trying to rotate an object so the pointy end will be what hits the enemies. I instantiate it with AddForce and this is the code of the Shooting Script. I've tried with Quaternion and transform but I've maybe missed something important
if (Input.GetKey(fireKey) && tm.canShoot)
{
//Makes the tank shoot
GameObject missile = Instantiate(missilePrefab, transform.position + transform.up * 2f, transform.rotation) as GameObject;
missile.GetComponent<Rigidbody2D>().AddForce(transform.up * missileForce);
missile.GetComponent<MissileScript>().owner = gameObject;

tm.canShoot = false;
Invoke("Reload", 3f);
}
}
public void Reload()
{
tm.canShoot = true;
}

 

First things first: Using code tags properly

Second, can you please show a screenshot of your current object (I assume it's the tank's cannon), and the missile, both with their default (Quaternion.identity) rotation? If both are set up correctly, using "transform.rotation" should give your missile the same rotation as the cannon, making it point the way it is shot.