"Venture Into Deep Space"
Kurland doesn't give an option to turn the mission in after going to Operations at DS9. The mission itself isn't listed when turning it in. He, however, shows any other mission you can do or have already. It also shows the checkmark above his head as if you can turn it in.
I've tried dropping the quest and getting it back from T'Nae, and relogging, but neither work
The only way to get this mission and the path of missions from it is by talking to him directly in Ops. He doesn't offer it through Hailing or anything else.