Once in a while a world event comes along so huge that everyone, decades later, remembers exactly where they were that day. D-Day, JFK’s assassination. Princess Diana’s death. 9/11.

July 20, 1969. I remember that day. It was sunny and hot. I was working in a law firm in London, England, just before leaving for Canada. Normally, the city buzzed with the usual rush of commerce and throngs of tourists. But the only talk in town was of three guys 393,309 kilometres away. People everywhere were glued to radios and televisions and the queues for the latest newspaper editions were deeper that soccer game line-ups. But this was the ultimate game in hardball science: Apollo 11’s mission to the surface of the moon aboard “Columbia’ and the landing craft ‘Eagle’.

The whole idea was incredulous right from the get-go. But from the moment the Soviet Union launched Sputnik 1 in October 1957 the space race between the Americans and the Russians was on. The Sputnik event spurred the formation of NASA in July 1958. On April 12, 1961, Russian Yuri Gagarin became the first man in space and within weeks Mercury astronaut Alan Shepard became the first American in space. But on May 25, 1961, President Kennedy raised the bar. “This nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth.”

Trouble was, he forgot to check with the scientists. No one had a clue how to do it. The 1960s was a time when you could still crank a car engine, televisions were made with valves, Elvis was hot, Vietnam was not and computers were six feet tall with 32K memory and less technology than a cell phone. But it sent anyone with Physics 101 scrambling for napkins to scribble down science formulas. They ultimately blossomed into the Gemini and Apollo programs and that remarkable spider machine called the Lunar Excursion Module (LEM).

Slung around the far side of the moon, Michael Collins, command module pilot, steadied Columbia as astronauts Neil Armstrong and Edwin ‘Buzz’ Aldrin took control of Eagle. “The eagle has wings!” Armstrong’s voice crackled over the airwaves to Mission Control as the two craft re-established contact with Houston. They flew in formation one more time around the moon before the LEM began its precarious descent to the surface.

“...Seventy-five feet... looking good,” Neil Armstrong’s voice hung between worlds. “Down a half...40 feet forward.... picking up some dust.... three feet....four forward.... drifting to the right a little... O.K.... Engine stopped. Houston. Tranquility Base here. The Eagle has landed.”

The most dangerous part of the whole mission was that last minute before landing. Flight director Gene Kranz in Mission Control had a team of brilliant young minds with an average age of just 26. But program alarms were sounding off. Communication to the LEM was weak. Eagle had just enough fuel to get to the pre-planned landing site. But the descent had started three seconds late and the craft was three miles beyond where it should have been. They were heading for a bolder-filled crater. Armstrong flew the Eagle manually like a helicopter looking for a safe landing as fuel got dangerously low. As they picked up that dust and the landing gear probe touched the surface, Aldrin shut the engine with just 15 seconds of fuel to spare. It was 4:17:42 pm EDT, 102 hours, 50 minutes, 42 seconds since leaving Earth. Six-and-a-half hours later, Armstrong would inch down that famous ladder.

“That’s one small step for man, one giant leap for mankind.”

Forty years on, it still is.