I was running the Sardok bounty and had just finished the Shrine of Oryx mission. While running around grabbing drops, I came across a big door at the back of the room. I remembered reading a forum post a day or two ago about Eris saying the purpose of our Ghosts is to open doors. On a whim, I pulled out my Ghost, and the door opened. I couldn't go through the door, but it did open. Now I have to try every door I come across.