Projectile Trajectory line in real time

Hello guys. I’m trying to draw a realtime line of the trajectory of a cannonball in 3 dimensions. It works, however, the line itself does not rotate correctly. It shows the trajectory of a cannonball, fired from the front of a ship, yet, the line only has the original rotation of the gameObject it starts from.

Can you guys look at this, and perhaps give me som tips/tricks on how to make this work the way i intend it to work?

Thanks in advance.

Here is the code.

    public Rigidbody projectile;
	public Vector3 muzzleVelocity;
	public float power;
	public GUIText powerGUI;
	
    void Update()
	{
		powerGUI.text = muzzleVelocity.ToString();
		
		if(Input.GetKey(KeyCode.Space))
		{
			muzzleVelocity = muzzleVelocity + power * Vector3.forward;
			Trajectory(gameObject.transform.position,muzzleVelocity,gameObject.transform.rotation, Vector3.down);
		}
		
        if (Input.GetKeyUp(KeyCode.Space))
		{
            Rigidbody clone;
            clone = Instantiate(projectile, transform.position, transform.rotation) as Rigidbody;
            clone.velocity = transform.TransformDirection(muzzleVelocity);
			muzzleVelocity = GameObject.Find("Ship").rigidbody.velocity + Vector3.forward * 10;
    	}
	}
	
	//Cannonball trajectory calculation and render
	void Trajectory(Vector3 initialPosition, Vector3 initialVelocity, Quaternion initialRotation, Vector3 gravity)
	{
		int trajectoryLineSteps = 100;
		float timeDelta = 1.0f / initialVelocity.magnitude;
		
		LineRenderer lineRenderer = GetComponent<LineRenderer>();
		lineRenderer.SetVertexCount(trajectoryLineSteps);
		
		Vector3 position = initialPosition;
		Vector3 velocity = initialVelocity;
		Quaternion rotation = initialRotation;
		
		for (int i = 0; i < trajectoryLineSteps; i++)
		{
			lineRenderer.SetPosition(i,position);
			lineRenderer.transform.Rotate(Vector3.up,Vector3.Angle(Vector3.zero,transform.position));
			
			position += velocity * timeDelta + 0.5f * gravity * timeDelta * timeDelta;
			velocity += gravity * timeDelta;
		}
		
	}

}

Like, if the cannon is pointed straight along the X axis when the game launches, then the line always points that way all the time, even if you move the cannon in game.