We know of the station Deep Space Nine of course, and we have heard of Deep Space Five, I believe. How many "Deep Space" stations are there? Which is the closest to Sector 001 and which is the farthest?
Please provide a source.
Memory Alpha lists the following 7 Deep Space Stations:
Memory Beta lists the following 25 Starfleet/Federation stations entitled 'Deep Space X':
I think the closest Deep Space station to Sector 001 was probably the Tau Ceti space station, with the Tau Ceti station being just 20 light years away (Source).
Based on looking through the below map, the farthest Deep Space station from Sector 001 is probably K7, right on the border of the Klingon Empire.
Please appreciate that not all of the space stations could be compared, simply because several of them are merely mentioned in passing and no specific location is provided.