 When they tried to put the flag, the post, into the ground, the lunar topsoil wasn't very deep. They couldn't get the post into the ground very deeply, but they managed to get it down just enough so the thing would stand. There was no wind. It wasn't going to blow over. But when the Apollo, the lunar module ascent vehicle took off, it produced the wind from the engines. And according to one report from Buzz Aldrin,