Fallen Astronaut is a 3.5-inch (8.9 cm) aluminum sculpture created by Paul Van Hoeydonck. It is a small stylized figure, meant to depict an astronaut in a spacesuit, intended to commemorate the astronauts and cosmonauts who have died in the advancement of space exploration. It was commissioned and placed on the Moon by the crew of Apollo 15 at Hadley Rille on August 1, 1971, next to a plaque listing the 14 men known who died. The statue lies horizontal on the ground among several footprints. The crew kept the memorial's existence a secret until after completion of their mission. After public disclosure, the National Air and Space Museum requested a replica of the statue. Controversy soon followed, as Van Hoeydonck claimed a different understanding of the agreement made with the astronauts and attempted to sell up to 950 copies of the statue. He finally relented under pressure from NASA, which had a strict policy against commercial exploitation of the US government space program.