Over the thump of the helicopter, Bill Wilcox listened to the crackling radio as man took his first steps on the moon.
But as he and his team of engineers flew over the Vietnamese jungle, Bill had his mind on something different - saving the lives of the soldiers who, somewhere below them, had been hit by a mine.
He had no idea that it was only moments until he and his comrades would be lying bleeding in the dust.
It was July 21, 1969, a day that changed the world - but it was also a day which changed Bill's life forever.
His story is one of courage in an event which inspired the lyrics of the famous Australian song, "I Was Only Nineteen" by Redgum.
And this year, at 2.20pm, Bill will be kneeling in the spot in the jungle where he was injured exactly 50 years before.
The call to battle
Bill Wilcox was raised in the small town of Oberon in the Central Tablelands of NSW, a fitter and turner by trade, and a bit of a larrikin.
But his world was altered on the day his birth date turned up in the 'lottery', as they used to call it, for young men to be conscripted to Vietnam.
"I didn't even hear it over the radio when they announced it. I just got my letter, telling me to go for a medical," he said.
The year was 1968 and Bill was 20 years old.
"I had mixed feelings about it. Poor old Mum didn't want me to go, but Dad was pretty good about it all. He had served in World War Two, so I figured if it was good enough for Dad, it was good enough for me."
Bill was to be an engineer in a reinforcement crew, which filled the spots of men who had been injured or killed.
"That was comforting," he joked.
Bill only completed his training one week before he was sent to war.
In April 1969, Bill boarded a plane at Mascot bound for Ho Chi Minh City.
"That was a pretty hard day," he remembered.
"It's just, you didn't know if you were coming back. Even poor old Dad was pretty upset then. All the other guys had family there, too. You could see them all standing there together as we boarded the plane."
But there were comforts.
"The plane had been hired by the army to take us there, so it wasn't even half full. So the trip was fun. The booze was flowing," he said.
"We had a stopover in Singapore. And they told us we had to wear a civilian shirt so we would blend in. But a bunch of blokes walking around wearing civilian shirts and army pants - we looked pretty funny."
But there was little time for fun - Bill arrived in Nui Dat by Caribou plane, set to begin operations the next day.
In the thick of it
Bill makes his job in Vietnam sound pretty straight forward - he was a field engineer, in charge of checking villages, tunnels and bridges for mines.
In truth, his job was a terrifying one. Checking tunnels for Viet Cong was no walk in the park.
Bill would enter small tunnels, which were only large enough to fit a small adult, and crawl in, feeling his way along.
"All you had was a torch, a pistol and a bayonet. You had to be pretty careful," he said.
"You had to feel along and find mines. Often there would be booby traps and trip wires.
"Our job was make sure it was OK, that there was no prisoners, and then blow it up."
Bill said they found all sorts of things in the tunnels besides Viet Cong, including food caches, and once a 20-man hospital.
It was also his job to destroy mines.
"If they found a mine that hadn't exploded, we had to explode it," he said.
One time Bill found a massive unexploded B52 bomb.
"And they said to me - 'you found it, you blow it up'," he said. "So we moved it away from the village and I blew it up.
"It was better than setting a cracker off."
A day of the moon and mines
"We've got a job in the Light Green."
This was the news Bill and his crew of engineers received from Corporal Dave Wright on July 21, 1969, when they were headed back to their Nui Dat base.
"We got word that the Third Platoon, A Company, 6th Battalion, the Royal Australian Regiment had walked into a minefield and we had to go and rescue the soldiers and replace the engineers," he said.
Six in all, the men were winched in to the jungle, because there was no landing spot for the helicopter.
Here they faced a frightening scene.
A hidden mine had exploded, and before them the damp jungle floor was littered with bleeding men.
"We found out that Lieutenant Peter Hines had accidentally stepped on a hidden mine," he said.
Eighteen men had been thrown off their feet in an explosion of dust and blood.
Lt Hines had used his dying breaths to instruct his men to complete their mine drill.
Faced with this scene, Bill and his team had the terrifying task of picking their way towards the wounded, while clearing a place for the helicopter to land.
"We found a marker on a tree with three prongs, which meant there were three mines," Bill said.
The men had already found one and safely destroyed before the second hit them, leaving only one mine to find.
"We would make 'safe lanes' after checking with the mine detectors, so everyone knew where it was safe to walk," Bill explained.
It was here that Bill met Frank Hunt - or 'Frankie' as he is called in Redgum's famous song.
Frank had lost half of his blood and had two broken legs, but Bill helped load him onto a stretcher and he was lifted out.
It was this moment where a medical officer stepped out of a safe lane and directly onto the third mine.
The massive explosion flung the men in a shower of dust and shrapnel.
"All I can remember was landing on the ground," Bill said. "I don't even remember the sound. But it made one hell of a hole.
"We didn't know at that stage where it had come from, or whether we were being attacked."
Bill said the only thing that saved his life was the fact the mine malfunctioned - instead of popping up above the ground, it exploded below the surface.
But he was lucky - the explosion took the life of his good friend Private Johnny Needs.
Bill was flung 20 feet away and lay bleeding with 60 wounds to his left side. His hand and his knee were smashed.
He remembers the heat of the wounds.
"Only one spot on my left side was untouched, and that was where the battery pack for the mine detector I was carrying sat on my upper leg," he said.
"The funny part was I wasn't in any pain. I don't know if it was adrenaline."
The helicopter was full, but Bill was in bad shape, so he was strapped to the skid.
He remembers seeing the trees as he was flown over the jungle.
"And I was thinking 'If I'm not dead now, I will be soon'."
And it was a close call - Bill was read his Last Rites both on the way and in hospital.
When the news of the mine incident got out, it shared the front page of the Sydney Morning Herald with the moon landing.
Bill was in surgery for 18 hours.
"The first thing I remember hearing when I came to was 'One small step for man, one giant leap for mankind'. They were replaying the moon landing in the hospital."
The metal man
Bill spent six days in intensive care in an American hospital at Vung Tau, before being sent to an Australian hospital for a week. He was keen to be on home soil, but he began bleeding internally, so he spent four more days in hospital at the Butterworth base in Malaya before flying home to Australia.
He couldn't walk for three months.
But Bill wasn't a quitter and he still had six months of his deployment left, and despite his injuries, he insisted on finishing his service.
He spent his time driving trucks and carrying out tasks for the Australian military.
To this day Bill still has many pieces of shrapnel lodged in his body.
"It makes going through metal detectors at the airport very interesting," he said.
A life of dedication
If you call by the Oberon RSL Sub Branch on a Saturday, you will see Bill and his good friend Neville Stapleton busy at work.
As the president of the branch, Bill has worked tirelessly to build up a wonderful place for veterans to meet.
He regularly meets up with other veterans, but one of the most memorable meetings was when he tracked down Frankie in 2017 after 48 years and they talked over old times.
Bill and Neville also work to take care of Legacy widows, taking them on outings and doing odd jobs for them.
He is also the president of Blue Mountains RSL.
But one of the lasting contributions they have made is building up an exceptional museum to honour those who have served in war.
Amongst the collection of artefacts, photos, weapons, letters and medals is Bill's most prized possession - the watch he was wearing the day he was hit.
And that watch is about to make a very special journey.
In 2010 Bill returned to Vietnam with his wife Sue to find the spot where he was injured.
"And as soon as I did that, I always planned to come back for the 50th anniversary," he said.
"It will be the last time I will go there.
"Where I was hit is in a North Vietnamese Army camp, so it still looks very familiar. A few trees are missing, but it looks exactly the same. They still use the trails we used 50 years ago."
Bill is heading back to Vietnam with his great niece Tara and great-great niece, nine-year-old Amelia, for eight days to honour the anniversary.
"I will show them around the places I knew, around Nui Dat and Long Tan," he said.
"I have mixed feelings about going back, but I'm glad I'll have the girls with me."
And on July 21, at 2.20pm local time, the exact anniversary of when he was hit, Bill will be in the spot he was injured.
"I hope some of the 6th Battalion will be there too," he said.
And while the rest of the world looks to the sky to celebrate the moon landing half a century ago, Bill won't be.
He'll be looking down, kneeling in the Vietnamese dirt, looking at the face of his watch, which is peppered with shrapnel holes.