This strat uses a shinespark to reach the missile location.

You can attempt a 2-tap short charge, and if you run into one of the enemies you can continue holding Dash and Left, and use your i-frames to get through the rest of the enemies. Then charge the shinespark, open the door, and spark through. After you crash against the wall, hold Left and Angle Down and fire a shot, and you'll pick up the item.