But one teenager, gazing at the endless sky from a window of a Russian school, was petrified.
It was Yuri’s niece, Tamara Filatova, who was 14 at the time.
“I was worried sick for him,” she says, sitting at the tiny Gagarin museum in the town where the first cosmonaut grew up – and which now bears his name.
“I remember that day – I was at school, and our teacher suddenly said: ‘Tamara, your uncle is a pilot, right?’
“‘Yes,’ I said.
“‘Well, do you know that he’s in space?'”
Tamara just wanted Yuri to come back to Earth, and only when her teacher announced 108 minutes later – the duration of his trip – that Gagarin had safely returned, was Tamara able to sigh with relief.
“At that time, although satellites had already been sent into orbit and animals flew and came back alive, space was still seen as something very scary, very dangerous, like a black abyss that could easily gulp someone.
“So my first feeling was that of extreme concern for a person I cared for deeply.”
Ms Filatova is one of those few people from Gagarin’s inner circle of family and friends who is willing to openly discuss his short but very eventful life.
The charismatic Russian cosmonaut was transformed into a hero when he returned from his brief trip to space.
Described as the first “citizen of the world”, Gagarin was welcomed by the capitalist US and socialist France alike, embraced by Fidel Castro and introduced to Queen Elizabeth II.
But the details of Mr Gagarin’s early years – especially of a rural childhood overshadowed by World War II – are more obscure.
The small village of Klushino lies about 200km from Moscow, surrounded by vast fields.
Clucking hens wander around old, lopsided wooden houses. A tractor roars nearby.
It looks just like many other Russian villages, but a sign off the main road – a dusty two-lane stretch of broken asphalt – reads: “Home of the first cosmonaut.”
But Klushino does not exactly look like the birthplace of a legend.
All that reminds us of the cosmonaut in Klushino is the sagging road sign with peeling, discoloured paint, and an old one-storey house. This house is an exact replica of the one where Yuri’s family lived before they moved to the nearby city of Gzhatsk (now renamed Gagarin).
Not only did the family take along all their possessions, but the walls and the ceilings too. Gagarin’s father completely dismantled the house, moved it to Gzhatsk and re-built it there.
A replica of the original Gagarin family home was constructed in Klushino in 1971 and has now been turned into a museum, cared for by a devoted worker who has been there for more than three decades – Nadezhda Yakovleva.
The museum in Klushino has never been funded by the government, she says. The cosmonaut’s family and friends, as well as a handful of people from the city of Gagarin, have been looking after the place as best they can.
This may explain the absence of tourists. Getting to Klushino is a pain – there are no proper roads, no infrastructure to welcome visitors, and there has never really been any kind of publicity campaign to draw attention to the forgotten village.
“Yuri was a very bubbly, fun-loving boy,” says Ms Yakovleva, who has spent years studying the life of the cosmonaut and his family, talking to his relatives and friends.
“The family lived here from 1933 to 1945. His father was a carpenter and his mum a milkmaid.”
The family – like many others in Russia – was thrown into turmoil during World War II.
Gagarin had just started in school when the German army invaded Klushino in November 1941, on their way towards Moscow.
Many villagers were forced out of their homes, and the Gagarin family had to leave the house in the hands of a Bavarian officer.
“They were allowed to stay on their land behind the house, where they grew vegetables,” says Ms Yakovleva, pointing to a patch of land that is now fenced off.
“So they constructed a tiny mud hut, where they spent the entire German occupation – a year and nine months.”
The mud hut’s replica in today’s Klushino is no more than three by three square metres, with a small table, two narrow bunk beds where the parents and two older children slept, and a heater which could also be used as a bed.
It was shared by Yuri, then aged seven, and his younger brother Boris.
Even after the occupation ended, school pupils had to use spent ammunition cartridges to learn addition and subtraction because of a lack of basic supplies.
Path to space
In early 1946, when the future cosmonaut was 13, the Gagarin family moved to Gzhatsk.
Yelena Kozlova taught Gagarin botany at school there.
“It was not his favourite subject, but he approached it very seriously, just like he did with physics and maths, which he enjoyed the most,” the 91-year-old former teacher recalls.
Gagarin liked pranks, she says, but he was always able to get people to forgive him.
“No-one was able to resist his smile! And girls always liked him, too.”
Ms Kozlova said that Gagarin was in the sixth grade when he joined the school’s aviation club and started dreaming of the stars.
Although his first job was as a foundryman, Gagarin later enrolled in the Saratov Technical College, where he learned to pilot a light aircraft.
Ms Filatova says: “When he was a student [in Saratov], he didn’t have much money, and to make some extra cash he had to work part-time as a dock labourer on the Volga River – and he used the money to buy presents for his family.
“My first real presents, like a bicycle, were from him.”
Gazing at her uncle’s picture on the wall at the museum in Gzhatsk, she says: “I loved Yuri very much. We were very close – he was only 13 years old when I was born and he became my godfather. But he was like my older brother, really – I could talk to him about anything.”
Feet on the ground
In 1955, Yuri Gagarin entered the Orenburg Pilot School, and upon graduation joined the Soviet air force as a lieutenant.
It was from among the best pilots that cosmonauts were selected.
Gagarin was just 27 years old when he blasted off on the first manned spaceflight.
“It was such an important day for everyone,” remembers his teacher Ms Kozlova.
“The school was closed for three days, there were celebrations everywhere.
“After he returned to Earth, he went to visit his parents here in Gzhatsk and came by his old school.
“When he approached me, his first question was: ‘How are your little girls?’ This touched me deeply. I thought then: ‘My God, he is world-famous, but he remembered to ask about my children!’
“Then he was called into a reception room where all the teachers had gathered. As he entered, everyone just froze. We were all shy and did not know how to address him properly.
“Then someone finally said: ‘Come in please, Mr Gagarin’.
“As he heard that, he laughed and replied: ‘Mr Gagarin? To you all, I will always be simply Yuri!'”
However keen he was to show that he still had his feet on the ground, Gagarin’s life had been transformed by his celebrity status.
But the cosmonaut continued with his training, keen to improve his skills as a pilot, eventually embarking on a fateful flight from which he would never return.
“He was supposed to come back for his father’s birthday in 30 March 1968 – he always used to come to his parents’ birthdays,” Tamara Filatova recalls.
“He called his dad and told him he’d be there. But three days before the birthday, on 27 March, he died in a plane crash.”
Exactly what went wrong on the training flight, and why Gagarin and his co-pilot Vladimir Seregin did not eject from the MiG-15 plane before it hit the ground at 600km/h, are unclear.
But theories abound. According to one idea, another jet – flying below its minimum altitude – triggered turbulence that caused the pilots to lose control of their plane.
The crash also gave rise to conspiracy theories and speculation, ranging from claims that Gagarin was drunk to suggestions that he was deliberately killed following a dispute with Soviet leader Leonid Brezhnev.
For Tamara Filatova, the different versions carry little meaning. All she cares about is that someone very dear to her passed away on 27 March 1968.
“It’s been so many years since he died, but I still can’t accept it,” says Ms Filatova.
“There is one thing that makes me very sad – that I don’t see him in my dreams.”