They had to make a U-turn or otherwise they would be flying off into outer space. Funny thing though, no one has ever taken a photograph of the edge of the earth. I asked a flat earther a few years ago on this site why this was and he said because going to the edge of the earth is a hard thing to do. I take from that that they are not very ambitious. They said that all photographic evidence of a round earth is fake yet do not provide any of there own. Another guy said once that there is no oxygen there at the edge. Yeah, well take and air tank for crying out loud. Truly pathetic responses.