An astronaut from Petaluma has returned to Earth. Forty-Five year-old Nicole Mann and three astronauts under her command splashed down into the Gulf of Mexico Saturday night after spending 157 days on the International Space Station. During her time in space, Mann participated in two space walks and conducted hundreds of experiments with her team. She is the first Native American woman in space being a member of the Wailacki of the Round Valley Indian Tribes in Northern California.