A petrol station owner and an Iraqi adventurer trying to fly from Oregon to Montana in tandem lawn chairs suspended from party balloons have had their dreams popped after thunderstorms forced them to abort their flight.

Kent Couch and Fareed Lafta were about seven hours into their flight when they were forced to descend, coming down near a reservoir about 30 miles east of their starting point.

But after they scrambled out of the contraption, it floated up again.

Flight organiser Mark Knowles said: "They came down hard. The craft went back up. It's sitting up in the sky right above us."

Earlier on, about 90 volunteers and several hundred onlookers counted down and then cheered as the pair lifted off from Mr Couch's Shell petrol station.                 

"The interesting thing is, anybody can do this," Mr Couch, the veteran of several lawn chair balloon flights, said before the flight. "They don't have to sit on the couch thinking,'I should have done it'. They can do it."

Mr Lafta, a mountain climber and skydiver, said he had shared Mr Couch's childhood dream of floating like a cloud.

Kent Couch has made several attempts before

He sent Mr Couch an email two winters ago after reading accounts of Mr Couch's earlier flights.

"I want to inspire Iraqis and say we need to defeat terrorists," Mr Lafta said. "We don't need just an army. We need ideology and to just have fun."

Volunteers filled 350 1.5-metre diameter red, white, blue and black balloons with helium and tied them to Mr Couch's homemade tandem lawn chair rig.

The balloons were arranged in bunches to represent the colors of the US and Iraqi flags. An American flag flew from the bottom of the framework supporting the chairs.
                 
Just before lift-off, they had to ask children in the crowd to return four balloons to provide extra lift.

The rig included 360kg of ballast. Besides a GPS, navigation gear, satellite phone, oxygen, two-way radios, eight cameras and parachutes, the couple were carrying two Red Ryder BB rifles and a pair of blowguns to shoot out enough balloons so they could float down to earth.

"The landings are very tough," Mr Couch said. "I don't think about the landings until I have to land. That's how I do it."

Expecting to float at 4,572 metres to 5,485 metres, where temperatures drop well below zero, they packed sleeping bags to stay warm.

Electronic gear was powered by a solar panel. A flare gun was tied onto the framework for emergencies. They also carried the ashes of a family friend to spread over the high desert.

Mr Couch said their biggest challenge had been finding enough helium to fill all the balloons. Each balloon that popped on inflation represented a $50 loss.

The flight was a warm-up for plans to fly a tandem lawn chair balloon rig in Baghdad sometime in the future.

Mr Couch's first time up was in 2006, when he got only 99 miles before the balloons started popping and he had to make an emergency landing.

In 2007, he flew 193 miles before running low on helium and landing in the sagebrush of eastern Oregon.

In 2008, things went much more smoothly. After lifting off at dawn July 5 with the help of scores of volunteers, Mr Couch floated at 35mph across the high desert, reaching his goal of crossing the Idaho state border.

Mr Couch was at it again in 2010, racing another lawn chair balloonist in a flight that went about 70 miles.