Gaelin served as a slicer on the world of Pembric II in the initial years following the establishment of the New Republic. Serving as a tech apprentice to the Keiffler Brothers, he provided assistance in their endeavors on the FarStar during the period when it was under the command of Moff Kentor Sarne. In contrast to the Brothers, Gaelin chose to go back to Pembric II and establish his own independent practice. Sarne tasked him with the responsibility of keeping an eye on Crev Bombaasa. Lacking both financial backing and influence, he found himself drawn into the Bombaasa Cartel, as Bombaasa held a deep distrust for anyone who had dealings with Sarne. Despite his strong desire to escape the planet, Gaelin was confined to a lab along with his equipment. Undeterred, he successfully transmitted reports to Sarne concerning Bombaasa until the moff's withdrawal from Kal'Shebbol.
In the year 8 ABY, a group arriving from the FarStar, with the help of Breslin Drake, freed Gaelin from his confinement, and he became a member of the corvette's crew. He discovered more than twenty-five distinct traps within the FarStar's systems, including the powerful tracking beacon. Nevertheless, his skills were not quite on par with those of his instructors, leading him to overlook a number of the more discreet traps.