Part 12: Dual Missle Upgrades
Moving on past the hot spots, you will start to notice some gray platforms. Which is a sign that a upgrade is near and that upgrade is a set of 5 more missles. Pass the upgrade is another hotspot. Get into the safezone and freeze the drifter. Now just wait for the rocks to pass and Samus will run into what looks like a dead end. Curl up and roll through the invisible wall. A few blocks will block your path, but that is when a bomb becomes useful.
On the otherside you will see the same thing that you have just went through. A hotspot with a drifter, do the same and move on. A sweeper will come into view, don't let it get you. Shoot the door wide open and Samus will now be in a vertical room. There is no where to go but down. Drop off and hold right to land on the edge below. Enter through the door where another sweeper waits. Another series of hot spots separates Samus from the next missle upgrade.
After all the hot spots a swarm is guarding the upgrade. Blast them into pieces and collect the second missle upgrade in this section. There is nothing else to discover, now Samus must head back. In the vertical room, shoot the blocks above to make them disappear and keep jumping til they reappear. Samus may take damage, but at least you will be able to get back up. Continue backtracking until you're in the elevator room.