I've listened to it and second that recommendation. The "13 minutes" is the amount of time it took for the Eagle to leave the orbiter and fall to the moon's surface. The episodes go through the history of the mission and the construction of the spaceship.

Finally, they play the entire 13-minute sequence. By that time, you understand the meaning of every communication between Eagle and Houston, all of the warning codes and calls and responses. It's good stuff.