TransNusa Air Services flies daily between Kalabahi airport and Kupang in West Timor, which can be reached via a connecting flight from Jakarta, Surabaya or Denpasar. However, as always in Indonesia, things can change quickly and frequently so for the latest information about flights check out tiket.com.
Pelni ships offer services to and from Kalabahi from a number of different points in eastern Indonesia. You can check schedules and prices on the link provided. If you’re island hopping over from the Solor Archipelago and don’t want to wait around for the next Pelni ship, head down to the nearest port and make inquiries about local passenger/car ferries which service the mostly short crossings much more regularly.