early missile expansions: burrow
To get this missile before the plasma beam, start in Hidden Court. From the ledge closest to the gate, space jump forward and left, landing on a bar. Get on the ledge next to this bar and approach the gate from the side. Do a single bomb jump or spring ball, using hyper ball at the peak to destroy the target from outside.
Space jump on the back of the gate itself, and again to a small ledge on your right. Destroy the second target to lower it and get inside Burrow.