Berlin (currently) has two airports:
Both are well-connected to Berlin-Mitte by public transport during all hours of the day!
You can come by train to the following train stations:
- Hauptbahnhof (main station), further taking S5 (-> Strausberg Nord), S7 (-> Ahrensfelde), S75 (-> Wartenberg) to S+U Jannowitzbrücke
- Ostbahnhof (east station), further taking S5 (-> Spandau), S7 (-> Potsdam Hbf), S75 (-> Spandau) to S+U Jannowitzbrücke
Deutsche Bahn is selling train tickets from all major German cities to Berlin.
Although sleep is not allowed at c-base (no joke!), you could however stay there overnight, if you're (with) a member and a cey member is keeping the space station open. The no-sleep-option is not something one might want to pursue for a couple of days though.
The below list is just an excerpt of what is available in the close surrounding (close to the S/U-Bahn lines U2, U8, S5, S7, S75).
Many hotels are located in Berlin-Mitte. You won't have trouble finding a room most likely, depending on if you're willing to pay for it.
There are plenty of (admittedly not necessarily nice) hostels in the close surroundings of the space station.