Buzz Aldrin called Armstrong "a true American hero and the best pilot I ever knew", and said he was disappointed that they would not be able to celebrate the 50th anniversary of the Moon landing together in 2019. Michael Collins said, "He was the best, and I will miss him terribly." NASA Administrator Charles F. Bolden, Jr. said, "As long as there are history books, Neil Armstrong will be included in them, remembered for taking humankind's first small step on a world beyond our own".