Security Station B is a room in the Agon Wastes. The room connects the Command Center to the Main Reactor.
The room is divided into two sections. The Command Center side has a corridor connecting two doors to the Command Center, the easternmost of these doors being a Red Blast Shield. The second section has two terminals, one of which can be scanned to download the Space Pirate Log entry "Log 07.013.6 (Federation Attack)." The two sections are separated by a gate that can only be lowered by shooting a white crystal with the Dark Beam.
When Samus first enters the room from the Command Center, she will see Dark Samus in the Reactor side, but will be unable to engage her.