The earliest scientific encampment on planet Gateway was established in the later half of the 2260s decade, after the USS Enterprise's first visits to this world. The scientists lived and worked in temporary lodgings near the location of the time portal. This expedition was massacred by Romulans who sought the Guardian's secrets in 2269, along with Enterprise landing party personnel defending the portal. The Romulans were stopped thanks to the efforts of Zar, Spock's son who had been born in Sarpeidon's ancient history. (TOS - The Yesterday Saga novels: Yesterday's Son, Time For Yesterday)