First Missile Room
|Adjacent rooms||Construction Zone|
If you can manage a turnaround as you grab the missile, then you can hold the Shot button during the item fanfare, and you will fire a shot as soon as play resumes. Otherwise you'll need to fire the shot after Samus is done turning around.
Optimally you should do a short-hop mockball after Samus has reached full run speed, which will take about half the room's width.
If you're not consistent at this short-hop mockball, you can use the door transition to your advantage: do a short hop and aim down into the door transition, then you can do the down-into-right inputs when the room loads.