Space balloon's final test

The pilots will take the balloon to a height of 25 miles

Final tests are being carried out on the largest helium balloon ever made before an attempt on the world altitude record.

Adventurers Andy Elson and Colin Prescot plan to take their balloon to an altitude of 25 miles, 132,000 ft, to break the 40-year record.

The pair will carry out a test inflation of the 1,500 ft (440m) high Somerset-made balloon from a ship off the Dorset coast, on Wednesday.

But weather conditions have forced them to delay their record attempt, due to take place off St Ives, in Cornwall, next month.

The balloon is higher than the Empire State Building

During the 11-hour flight Mr Prescot, 51, from Stockbridge, Hants, and Andy Elson, 48, from Wells, Somerset, will be strapped to an open flight deck, wearing space suits.

"We're really looking forward to it," said Mr Elson.

"This is the final test session, the whole team are revved up and ready to go."

The flight would break the current record, set by two Americans in 1961, by 18,000 ft.

Mr Elson said the risk had been minimised.

"The idea is for the team of engineers and scientists to design out the risk," he said.

"During the course of the project I will probably drive 100,000 miles on the roads in Britain, the risk in driving 100,000 miles in 18 months is about the same as making this flight."

Research about the climate conditions have forced the team to review their plans.

"We've got a few weather problems.

We're trying to bring science and space to Britain

Pilot Andy Elson

"The upper winds are very strong and there is a lot of cosmic radiation because of the high solar activity.

"That runs in a cycle and this is a peak year for the cycle, that's come out of the research we've been doing."

But he said the climactic conditions are set to die down by late September or early October.

The pair will carry out a series of experiments during the planned flight.

"We're trying to bring science and space to Britain," he said.

"We'd like to make Britain the third nation to put a man into space.

"One experiment will look at cosmic radiation because the next generation of passenger aircraft will be travelling above 60,000 ft and the affects of cosmic radiation aren't known about."