Here is my 100% Guide for Deliver Us The Moon!
This is obtained in chapter 2 (Pearson Space Station).
Once you get into the central command area (Basically one round room, with seats in the middle and a monitor).
Head out of an exit, until you find something called "Ol Lybra" on the wall.. Go through the pipe here and down.
You will have to turn yourself the right way up using either
Once your the right way up, go to the right in the sleeping quarters, on the left you see Sarahs room which has an audio log in it.
On the right hand side door, is Rolfs room.
Head into Rolfs room, interact with the telescope there and wait until a cute little teddy bear floats on by.
Go to 33:00 in the video to see how and where this unlocks.
Hope This Helps!