Jim Lovell clearly wants to give the impression of a still spry octogenarian. The veteran of Gemini 7, Gemini 12, Apollo 8 and commander of Apollo 13 appears with a spring in his step. Recently returned from a skiing trip, he has the same bright blue eyes that stare out from the yellowing magazine covers – Time, Newsweek, Paris Match – that adorn the walls of the suburban Chicago restaurant owned by his son.

But as the former astronaut, who turned 83 on March 25, climbs the stairs to his office, his age starts to show. His shoulders hunch over, one nostril is caked in dry blood because of a sinus problem, and he confesses that the skiing trip was probably his last.

The office is cluttered with books for signing events and memorabilia from the Apollo 13 film. Lovell is genial, direct and plain-spoken. He talks fast and without superlatives, fitting for a man chiefly remembered for one of history’s most famous understatements – “Houston, we have a problem” (In fact, he actually said, “Houston, we’ve had a problem.”)

Lovell situates his life within the history of flight. “I was born a year after Lindbergh made his historic trip across the Atlantic,” he says. “Boys like either dinosaurs or airplanes. I was very much an airplane boy.”

As a child, he built home-made rockets in his back garden using US postal service mailing tubes. “For fuel, we mixed sulphur, potassium nitrate and charcoal – the ingredients of gunpowder,” he laughs. “They flew – not much, but about 80-100 feet.”

Even so, it was not obviously Lovell’s fate to be an astronaut, and anyone less determined might not have made it. His first application to the US Naval Academy was rejected. His first attempt to be a Navy pilot was also dismissed. He failed to pass the first round of astronaut selections. His second application was successful and he joined Nasa in 1962, making his first space flight three years later, aboard Gemini 7.

Lovell is the only person to have travelled to the moon twice without landing on it. He was to have done so in 1970 on Apollo 13, but an explosion crippled the craft, forcing the crew to squeeze into the lunar module, which they used as a lifeboat to return to Earth.

While the accident aboard Apollo 13 gave the US its first knife-edge space drama, Lovell says the highlight of his career was two years earlier, on Apollo 8. “We got to the moon on Christmas Eve 1968, at the end of a poor year for this country. We had Vietnam. We had civil unrest. We had the assassinations of Robert Kennedy and Martin Luther King. But we went around the moon and saw the far side for the first time. A script writer couldn’t have done a better job of raising people’s hope.”

Lovell and his peers were lionised in their day. Twenty-five years later, Ron Howard honored him again on the big screen. “I was only a hero by default,” he says. “The flights were few and far between. There weren’t that many astronauts. The moon flights were so interesting and exciting.” But ultimately, he admits, the early space flights “made people proud to be American”.

He thinks the current US space program has lost its way.

“NASA put the cart before the horse. If you’re going to go into space, you have to have an objective, a mission. Where do you want to go? Earth orbit? The moon? Mars? What’s the technology to get there? You develop the technology for the mission. The present space programme wants to develop technology but they don’t know what to do with it.”

Lovell and the Apollo 13 crew traveled farther into space than any other humans ever had, or have since. “We didn’t slow down, unlike the others, when we got to the moon because we needed its gravity to get back, so we hold the altitude record. I never even thought about it. Records are only made to be broken.”

What does he recall from his time in space? “The impression I got up there wasn’t what the moon looked like so close up, but what the Earth looked like,” he says.

“The lunar flights give you a correct perception of our existence. You look back at Earth from the moon and you can put your thumb up to the window and hide the Earth behind your thumb. Everything you’ve ever known is behind your thumb, and that blue-and-white ball is orbiting a rather normal star, tucked away on the outer edge of a galaxy. You realise how insignificant we really all are. Everything you’ve ever known – all those arguments and wars – is right behind your thumb.”

Lovell is warming to his philosophical theme, but after 90 minutes of talking, he is also flagging, and keen to join his family for dinner.

“People say: Did you violate Heaven?” he says. “Well, God is down here too. If you believe in God, you believe in God here as well as 240,000 miles away.”