The Enclave relay 0X9-B, referred to as the satellite relay station, is a large building inhabited by Enclave troops and some robots, reached through the Rockland Car Tunnel. It has one interior section.
The exterior is a small valley stretching from north to south. The collapsed end of Rockland Car Tunnel and the door through which the area is accessed is at the southern end while the satellite relay station itself and another collapsed car tunnel are at the northern one. The valley itself is split into an elevated road on the eastern side and a wider grass area to the west. The road is initially blocked by Enclave force-fields and the whole area is fortified with automated turrets. A multitude of Enclave soldiers protects the area.
The facility itself is a fairly extensive, yet linear building spanning across multiple floors and guarded by 32 Enclave soldiers in total. The first room encountered when entering the facility itself is filled with rubble. The only way further inside the building is a small service tunnel with a small locker room on the side which ends in a room with generators, computers and a metal staircase leading upwards.
While the intermediary level holds nothing of interest, the topmost level has room with tables and more computers on the one side and a small corridor on the other. After passing by yet another computer room, the corridor ends in another staircase, this time leading downwards. At the bottom level, there is a storage room or lounge connected to another service tunnel. Featuring a lot of crates and a barricade, the tunnel opens out into room with pipes on its floor. Yet another metal staircase leads to a room with microfiche readers and more computers with a small bathroom on the side. A large door at the end reveals the next service tunnel which is fairly shortly and ends in a computer room with a satellite uplink terminal. Stairs guarded by an automated turret lead to the building's other exit to the Capital Wasteland, up a cliff north of Rockland Car Tunnel.
This area has its own world map, i.e. it's technically not part of the Capital Wasteland.
When you exploit the glitch to gain the Beta Tesla cannon, you are able to drop down onto a ledge with burning transformers and dead Enclave soldiers on it. The door, although it can be opened, leads nowhere.
Depending on your choice at the end of Broken Steel, when you return here you find that Liberty Prime's head is still here, but also at the Citadel, strangely.
If you return here during Who Dares Wins, the goal marker on the HUD will point to the tunnel. On the map, the tunnel will just be a point on the path to the goal. The path will extend from you, to the tunnel, to far off the southwestern corner of the map. It will then return to the map from somewhere to the south and head to a point almost on the path leading from the tunnel. Finally, from there it will lead to a goal marker right by the southern most satellite dish.
It appears that the first point from the player may actually appear at any location on the map instead of just the tunnel, such as the entrance to the facility. The goal marker on the HUD will always point to the location of the first point.
Should you re-enter the base after you have already gone through during Who Dares Wins, you may find it re-filled with more Enclave soldiers that will attack you normally, but they have no armor on. When you kill them, however, and search them, you will find that they are still carrying armor.