For 75 years the sonnet High Flight, by Royal Canadian Air Force (RCAF) pilot John Gillespie Magee Jr, has been a favourite poem of aviators the world over.
Describing the elation and freedom of flight, it was most famously quoted in January 1986, by then-US President Ronald Reagan following the Challenger space shuttle disaster.
Russell Crowe also recites it in his film For The Moment.
Yet High Flight was first penned in the skies above the wartime RAF base at Llandow in the Vale of Glamorgan, south Wales.
On 18 August 1941, a 19-year-old Magee was taking part in a high altitude Spitfire training flight when he was struck by the phrase "to touch the face of God".
On touching down, he finished the rest of the words and posted them on the back of a letter to his parents in Washington DC.
It said: "I am enclosing a verse I wrote the other day. It started at 30,000 feet, and was finished soon after I landed. I thought it might interest you."
High Flight's 75th anniversary is to be marked at a ceremony at the MoD St Athan station church on Thursday - beneath the skies where some of the words could potentially have been dreamt-up.
The Venerable (Air Vice-Marshal) Jonathan Chaffey QHC, Chaplain-in-Chief of the Royal Air Force, summed up the appeal of the poem.
"In High Flight, Magee captures the joyous freedom and deeper sense of spiritual insight he and subsequent pilots have found in flying.
"It has significance for many members of the Royal Air Force, as they discover in its words an expression of the joy, spirituality and pathos of their own experiences."
Tragically, just a few months after writing High Flight, Magee was killed in a mid-air collision over Lincolnshire.
He was buried there at Scopwick Cemetery, near Digby, and the first and last lines of the poem are inscribed on his grave.
American and Canadian RAF personnel visited Lincolnshire in 2011, to mark the 70th anniversary of the death.
Thursday's service at St Athan will be attended by John Gillespie Magee's younger brother - Padre Magee - who is now in his early nineties.