Gotana-Retz was an astronaut from Kelemane's planet, a planet with a tachyon core which caused a differential in space-time such that each second that passed on the orbiting USS Voyager was the equivalent of an entire day on his planet.
Retz was part of a mission, Orbital 1, sent to investigate the ancient "Sky Ship" which was revered by the people of his planet. When Captain Janeway explained the situation and asked him for his help Retz agreed to return to the surface and enlist the aid of his people. A short time later Voyager came under attack from the surface.
Retz returned to his planet with specifications of Voyager and convinced his people to help Voyager break orbit. Two ships from the planet surface returned and used a tractor beam to break Voyager free. (VOY: "Blink of an Eye")