Use the door controls to the right side of the door for an interesting puzzle. The answers are as follows, in this order:
1. Rotate the center block counter-clockwise
2. Rotate the rightmost block clockwise
3. Rotate the leftmost block counter-clockwise
And the door will open. Speak with B-4R5 inside to receive your blank transponder code card, precisely the item Tienn Tubb needs back at the Landing Pad to allow you to be caught by Goto's Yacht - which, by the way, happens automatically after you leave. As you make your way back to the docks, you'll encounter three HK-50's waiting for you at #15a. See above for details.