It was broadcast around the world, but Neil Armstrong's first steps on the moon might not have been witnessed without a number of Australians, and Australian technology.
David Cooke is 87 years old and enjoying retirement.
But 50 years ago, the Australian was working as a receiver engineer in Parkes, a country town of just 8,500 people in NSW, when history was made.
Mr Cooke was inside the Parkes telescope - colloquially known as "the dish" - when Neil Armstrong became the first person to set foot on the moon.
"Most of us were watching this little green TV set where we could see the landing module sitting on the surface of the moon," he told SBS News ahead of the 50th anniversary of the moon landing this week.
"And then Armstrong coming down the ladder and finally putting his foot down onto the moon, and making his famous speech"
"I think a big cheer must have gone up when that happened."
It was 21 July 1969 and 12.56pm on Australia's east coast when Armstrong took those first steps, and the Parkes telescope helped NASA share the pictures of it on TV sets around the world.
Watching were 600 million people - or about a fifth of the world's population at the time.
Nineteen minutes later, Buzz Aldrin joined him, while Michael Collins stayed on board the command module Columbia, in lunar orbit.
There was still work to be done - and it was only once it was over, that the enormity of the achievement really dawned on Mr Cooke.
"I went down outside the telescope with my camera and took a photo of the telescope, which included the storm which was disappearing," he said.
"And I thought to myself, well how amazing is all this, that all these people have co-operated together to make this possible, and up there on the moon that I could see there were three people, three men, two of them on the surface of the moon.
I thought to myself, well how amazing is all this, that all these people have co-operated together to make this possible.
- David Cooke, 1969 Parkes engineer
"And they'd successfully been put there. I was quite amazed that we had been a part of doing that."
How was TV broadcast from the moon?
Signals were received from the moon by NASA's tracking station in Goldstone, California, and facilities at Honeysuckle Creek, near Canberra, and Parkes, about 400 kilometres west of Sydney.
Other stations in Australia also played a key role in the mission, including Tidbinbilla in the ACT, Carnarvon in WA and the Culgoora radioheliograph in NSW.
The Parkes radio telescope opened in 1961, and has a diameter of 64 metres, making it one of the largest single-dish telescopes in the southern hemisphere.
"The Parkes telescope was the most advanced, and one of the most sensitive radio telescopes in the world," the telescope's current operational scientist John Sarkissian said.
"And NASA wanted the most sensitive, most advanced instruments tracking the lunar module at those very critical moments, and the CSIRO agreed to do that, specifically for the reception of the moonwalk TV."
The broadcast operation was many months in the making, and the Australian receivers were recruited by NASA a year before, in 1968.
NASA needed 24-hour contact with Apollo 11, and that could only be achieved by having receivers on the opposite side of the planet to the United States.
At the start of the broadcast, NASA switched between vision from Goldstone and Honeysuckle Creek - but because of Parkes's superior technology, it was able to provide a vastly clearer picture.
Once the switch was made to the vision from Parkes, NASA stayed with it for the remaining two-and-a-half hours of the broadcast from the moon.
"When they switched to Parkes, about eight minutes into the broadcast, it was so much better, they stayed with Parkes," Mr Sarkissian said.
"When you see the video of the switching, and then the final switch to Parkes, it's obvious that Parkes had the very best picture.
"So, thanks to Parkes, the world was able to view the moonwalk with the greatest possible clarity."
It nearly didn't happen
The telescope was fully tipped over to see the moon when a series of wind gusts, some reaching around 110 kilometres per hour, hit Parkes.
The telescope's then-director, John Bolton, kept the dish operating throughout the broadcast, despite the safety rating of only 40 kilometres per hour.
Mr Bolton could have taken the Parkes telescope offline to protect it, but that would have left NASA with only the lower-quality pictures from the other stations.
The legacy of the moon landing
Fred Watson knows a thing or two about space.
He's an astronomer with the Australian Astronomical Observatory and says the moon landing is one of mankind's greatest achievements.
"I think it was one of the defining moments of our species, because for the first time a terrestrial species, namely homo sapiens, set foot on another world," Mr Watson said.
"It is a staggering achievement, and especially when you look at the kind of technology that was available at the time.
"The 1960s technology, compared with what we have today, left a lot to be desired. So I really think it was a defining achievement."
NASA has plans to send people back to the moon by 2024. It's an ambitious deadline, set by US President Donald Trump.
NASA hasn't developed a lunar lander since the end of the Apollo program in 1972.