I'm trying to set up a comms network by throwing up some satellite in low Kerbin orbit. I've watched a couple of tutorials and built myself an SSTO with a cargo bay. I then built a satellite small enough to fit in the cargo bay, but I'm having no luck at all trying to get the satellite loaded into the bay. How is it done? I loaded up the SSTO then load/merged my satellite in there but I can't get it to attach to the rear or front of the cargo bay. I've tried couplers on the satellite and on the cargo bay but no luck. I tried using docking ports instead of a coupler but that too did not work at all.
What am I missing? I'm guessing it's something simple that I've not picked up on in the tutorials. How do you guys load and mount satellites in cargo bays?