The Cornish jinx struck out of the blue on a perfect morning for launching a balloon.
By Helen Briggs
BBC News Online science reporter, in St Ives
Weather conditions were excellent off southwest England with a clear sky and a gentle wind.
Triton launch ship: Everything seemed to be going so well
However, two-thirds of balloon missions fail before they get off the ground and this was the fate of the world's largest helium balloon built for manned flight.
As it was being pumped with 44 million cubic feet of the gas - enough to fill almost four billion party balloons - something went wrong.
It is possible the balloon became twisted as it was being unfurled on the deck of its launch ship, RV Triton, some 20 kilometres (12 miles) out to sea, and a seam split.
HISTORIC BALLOON FLIGHTS
Pilots have constantly pushed the latest technology to fly their balloons ever higher and further
There wasn't enough helium to refill the fragile envelope - even if it could be repaired - so the mission had to be called off.
All or nothing
For pilots Andy Elson and Colin Prescot it is a devastating blow.
After three years of preparation, their one chance to launch this year has been thwarted by a technical problem.
Disappointment was etched on the face of mission controller Brian Jones at a hastily convened media conference at the mission's temporary HQ on the cliffs above St Ives.
"Things were going extraordinarily well and because of that I think it's an even more devastating blow for the team on board and for us at mission control," he said.
As he pointed out, the team had only one shot at filling the balloon. It had never been fully inflated before and now never will be.
But Jones, who holds three world ballooning records including the longest flight around the Northern Hemisphere, is no stranger to the challenges of the game.
It took 22 goes to fly a balloon successfully around the world and the altitude record has not even been attempted since 1961.
"It's a technical challenge; it's a great adventure; it's a personal challenge for the pilots - why should we stop now?" he said.
Fully inflated it would have been as tall as the Empire State Building
When I arrived in Cornwall on Monday, the staff at my hotel joked that the balloon would never get off the ground.
"It's the Cornish jinx," they said. "It always happens here - we had the eclipse and it rained."
In the end they were right - for this year anyway. But there is no indication that the pilots, who were prepared to risk their lives in pursuit of the record, will give up now.