iOS change direction of moving sprites in Spritecode

[rubu]

Okay heres what i want to do:
i got a bullet. At the moment its moving across the screen on the x-axis.
I want to get i moving up.

    CGPoint location = CGPointMake(self.frame.size.width, _ship.position.y);
    SKAction *laserMoveAction = [SKAction moveTo:location duration:.5];

the above is the code that makes the bullet (laser) moving.
How do i get the laser up?