About 19minutes after Armstrong's first step, Aldrin joined him on the surface, becoming the second human to walk on the Moon. They began their tasks of investigating how easily a person could operate on the lunar surface. Armstrong unveiled a plaque commemorating the flight, and with Aldrin, planted the flag of the United States. Although Armstrong had wanted the flag to be draped on the flagpole, it was decided to use a metal rod to hold it horizontally. However, the rod did not fully extend, leaving the flag with a slightly wavy appearance, as if there were a breeze. Shortly after the flag planting, President Richard Nixon spoke to them by telephone from his office. He spoke for about a minute, after which Armstrong responded for about thirty seconds. In the Apollo 11 photographic record, there are only five images of Armstrong partly shown or reflected. The mission was planned to the minute, with the majority of photographic tasks performed by Armstrong with the single Hasselblad camera.