"Some years ago, I was lucky enough invited to a gathering of great and good people: artists and scientists, writers and discoverers of things. And I felt that at any moment they would realise that I didn't qualify to be there, among these people who had really done things. On my second or third night there, I was standing at the back of the hall, while a musical entertainment happened, and I started talking to a very nice, polite, elderly gentleman about several things, including our shared first name. And then he pointed to the hall of people, and said words to the effect of, "I just look at all these people, and I think, what the heck am I doing here? They’ve made amazing things. I just went where I was sent." And I said, "Yes. But you were the first man on the moon. I think that counts for something." And I felt a bit better. Because if Neil Armstrong felt like an imposter, maybe everyone did."

"His achievements were the stuff of legend, and I am lucky to have known him, if only for a brief time, I am sad that he's gone, proud as a member of the human race that he did what he did for all of us."

"You got a bunch of guys about to turn blue. We're breathing again."

"As the first human to land on any world outside the Earth, and probably the first living creature of any sort to come from the Earth and reach the Moon, his legacy will be safe as long as intelligent life survives in this corner of the cosmos."

"He was the best, and I will miss him terribly."

"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. [...] Besides being one of America's greatest explorers, Neil carried himself with a grace and humility that was an example to us all. When President Kennedy challenged the nation to send a human to the Moon, Neil Armstrong accepted without reservation. As we enter this next era of space exploration, we do so standing on the shoulders of Neil Armstrong. We mourn the passing of a friend, fellow astronaut and true American hero."

"I am deeply saddened by the passing of my good friend, and space exploration companion, Neil Armstrong today. As Neil, Mike Collins and I trained together for our historic Apollo 11 Mission, we understood the many technical challenges we faced, as well as the importance and profound implications of this historic journey. [...] Whenever I look at the Moon I am reminded of that precious moment, over four decades ago, when Neil and I stood on the desolate, barren, yet beautiful, Sea of Tranquility, looking back at our brilliant blue planet Earth suspended in the darkness of space, I realized that even though we were farther away from Earth than two humans had ever been, we were not alone. Virtually the entire world took that memorable journey with us. I know I am joined by many millions of others from around the world in mourning the passing of a true American hero and the best pilot I ever knew. My friend Neil took the small step but giant leap that changed the world and will forever be remembered as a historic moment in human history."

"Neil Armstrong was also a reluctant American hero who always believed he was just doing his job. He served his Nation proudly, as a navy fighter pilot, test pilot, and astronaut. He remained an advocate of aviation and exploration throughout his life and never lost his boyhood wonder of these pursuits."

"I believe that every human has a finite number of heartbeats. I don't intend to waste any of mine running around doing exercises."

"During my testimony (to the House Science and Technology Committee) in May I said, “Some question why Americans should return to the Moon. “After all,” they say “we have already been there.” I find that mystifying. It would be as if 16th century monarchs proclaimed that “we need not go to the New World, we have already been there.” Or as if President Thomas Jefferson announced in 1803 that Americans “need not go west of the Mississippi, the Lewis and Clark Expedition has already been there.” Americans have visited and examined 6 locations on Luna, varying in size from a suburban lot to a small township. That leaves more than 14 million square miles yet to explore."

"Later Apollo flights were able to do more and move further in order to cover larger areas, particularly when the Lunar Rover vehicle became available in 1971."

"Preflight planners wanted us to stay in TV range so that they could learn from our results how they could best plan for future missions. I candidly admit that I knowingly and deliberately left the planned working area out of TV coverage to examine and photograph the interior crater walls for possible bedrock exposure or other useful information."

"There was great uncertainty about how well we would be able to walk in our cumbersome pressurized suit."

"It is true that we were cautious in our planning. There were many uncertainties about how well our Lunar module systems and our Pressure suit and backpack would match the engineering predictions in the hostile lunar environment. We were operating in a near perfect vacuum with the temperature well above 200 degrees Fahrenheit with the local gravity only one sixth that of Earth. That combination cannot be duplicated here on Earth, but we tried as best we could to test our equipment for those conditions. For example, because normal air conditioning is inadequate for lunar conditions, we were required to use cold water to cool the interior of our suits. We did not have any data to tell us how long the small water tank in our backpacks would suffice. NASA officials limited our surface working time to 2 and 3/4 hours on that first surface exploration to assure that we would not expire of hyperthermia."

"For The United States, the leading space faring nation for nearly half a century, to be without carriage to low Earth orbit and with no human exploration capability to go beyond Earth orbit for an indeterminate time into the future, destines our nation to become one of second or even third rate stature. While the President's plan envisages humans traveling away from Earth and perhaps toward Mars at some time in the future, the lack of developed rockets and spacecraft will assure that ability will not be available for many years. Without the skill and experience that actual spacecraft operation provides, the USA is far too likely to be on a long downhill slide to mediocrity. America must decide if it wishes to remain a leader in space. If it does, we should institute a program which will give us the very best chance of achieving that goal."

"It would be impossible to overstate the appreciation that we on the crew feel for your dedication and the quality of your work."