How do you get through that locked door in that czerka station?

Bay 1 door get the ebon hawk and return to citidel station (this is where you will land)

Bay 2 (ithiorian docking bay) door complete ithorian missions to get the shuttle, or get the ithiorian credidentials from lorso to steal the droid, or for the black market lie to the ithiorian gate gaurd to steal the prototype shield

Bay 3 door (czerka docking bay) complete the czerka missions

There is also a way to get into the czerka bay WITHOUT doing the czerka missions. Here's what you need to do:

1: Do everything on Telos UNTIL you get to the point where you deliver the droid and get the illegal gun
2: talk to grenn and start the black market side quest
3: go back to grenn and tell him about it to get the goods case
4: make sure you're alone, or else it has a high chance of not working
5: go to the dealer and give him the case, which will take you inside the bay

Here's the tricky part: you want to not engage the dealer, rather you want to go into the storage room for as long as possible (that's what I did, hoping there would be goodies) eventually, grenn and the tsf would have knocked out samhan, and when they do, you can go out of the storage room and explore the bay. If you want to leave, just talk to samhan. (Talking to grenn or the tsf won't do anything). There you go, a light side way to get the bay 3 map