Paul McCartney has asked NASA officials to withdraw their support fund for testing of radiation used with spider monkeys. He believes that researchers can find a solution so that the animals are not used as guinea pigs. According to the website Starpulse.com Paul McCartney wrote a letter to the director of NASA, Charles Bolden, and said: "I think NASA has enough ingenuity to examine the effects of space travel without confinement and do experiments on animals. I'll be terribly disappointed if, in your eagerness to explore new frontiers and learn more things about the fascinating world we live in, you start to fall in your treatments to animals with whom we share this planet. I ask you to stop these experiences.