About six hours into their flight, Kent Couch and Fareed Lafta started to descend from an altitude of 10,000 feet because of the weather, flight organizer Mark Knowles told The Associated Press.
The website tracker showed them about five miles south of the town of Prineville, about 30 miles northeast of their starting point. The pair initially floated about 40 miles north before winds sent them back south, then east, the direction they wanted to go.
"Thunderstorms are around them," Knowles said by cellphone. "We've got visual contact. I can't see their faces."
Earlier, volunteers filled 350 5-foot diameter red, white, blue and black balloons with helium and tied them to Couch's homemade tandem lawn chair rig. The balloons were arranged in bunches to represent the colors of the U.S. and Iraqi flags. An American flag flew from the bottom of the framework supporting the chairs.
Just before liftoff, they had to ask children in the crowd to return four balloons to provide extra lift.
About 90 volunteers and several hundred onlookers counted down and then cheered as the pair lifted off from Couch's Shell gas station. The duo safely cleared a two-story motel, a coffee stand and a light post.
The rig included 800 pounds of ballast - red Kool-Aid in 40-gallon barrels. Besides a GPS, navigation gear, satellite phone, oxygen, two-way radios, eight cameras, and parachutes, they were carrying two Red Ryder BB rifles and a pair of blowguns to shoot out enough balloons to come to earth when the time is right.
Expecting to float at 15,000-18,000 feet, where temperatures drop to near zero, they also 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.
Lance Schliep, an appliance repairman, helped Couch with the latest design, made entirely from items bought at local hardware stores and junk from Couch's garage.
"It's about as redneck as you can get," Couch said.
Lafta, a mountain climber and sky diver, said he had shared Couch's childhood dream of floating like a cloud. He sent Couch an email two winters ago after reading accounts of Couch's earlier flights.
"I want to inspire Iraqis and say we need to defeat terrorists," Lafta said. "We don't need just an Army. We need ideology and to just have fun."
Couch said their biggest challenge was finding enough helium to fill all the balloons. They sent as far as the Midwest for bottles. Each balloon that popped on inflation represented a $50 loss, but Couch would not divulge the total cost.
"The interesting thing is, anybody can do this," he said before the flight. "They don't have to sit on the couch thinking, 'I should have done it.' They can do it."
The two men had hoped to fly through the night across the mountains of Idaho and touch down Sunday morning somewhere in southwestern Montana.
The flight was a warm-up for plans to fly a tandem lawn chair balloon rig in Baghdad sometime in the future.
Couch said receiving Lafta's email in the dead of winter, at a time he was bored, inspired him to go aloft again.
"I never really thought I would do it again," Couch said. "I thought I had had enough excitement.
"I started thinking, it sounds fun. It takes six months after you land for your brain to get over the fear and just the emotions."
They planned to fly over Iraq last year, but ran into problems getting permission from the government.
"I really enjoy being able to share the experience with somebody else," Couch said. "I could only tell people about the experience," until now.
Couch has wanted to float like a cloud since he was a child, and was inspired by a TV show about the 1982 lawn chair flight over Los Angeles by truck driver Larry Walters, who gained urban myth immortality.
Couch's first time up was in 2006, when he got only 99 miles before the balloons started popping and he had to bail out.
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, he floated at 35 mph across the high desert, reaching his goal of crossing the Idaho border. That's when he pulled out his trusty BB rifle and shot out enough balloons to come to earth in a pasture outside the tiny farming community of Cambridge, Idaho.
Couch was at it again in 2010, racing another lawn chair balloonist in a flight that went about 70 miles.