On the left of the picture (forward) you can see the boundary layer fence. Those little sections hinged up to create a boundary layer that separated from the aircraft and flowed over the door opening before reattaching aft of the door.

To the right of the main portion of the telescope "spider" you can see two smaller telescopes which are bore-sighted down the main telescope's axis. These were the acquisition and tracking telescopes that were used to point the main telescope. Each was attached to an extreme low-light, image intensified television camera.