Lawn Chair PilotsJoe Barbera and his team will launch a cluster of three weather balloons and a modest payload Sunday morning from a field next to his house.If things work out well this weekend, the half-dozen guys will try it again later this month on a larger scale. And on that June 21 flight, the payload will include Barbera.He’s looking forward to seeing the world from his high-flying lawn chair.“It’s seriously cool technology, but it’s stuff you can build in your backyard,” Barbera said.Lawn-chair ballooning has been on his to-do list for more than 30 years, Barbera said. So, this is not a spur-of-the moment enterprise.That’s the reason for Sunday’s test flight, when three helium-filled balloons — each about 5 feet in diameter — will lift off with a payload of about 11 pounds.“We’re doing an unmanned flight first, to prove a couple of technology things,” Barbera said.The launch is tentatively scheduled for 10 a.m. “Maybe earlier, depending on the weather,” Barbera said.“We need winds that are blowing away from Portland and Seattle, to the northeast,” he said at his home in a wooded area north of Battle Ground.The team has plotted out a climb rate of about a meter a second. It’s a slow, steady ascent — not the trajectory of a rocket launch — although they need enough lift to ensure that the craft will actually leave his own property. Joe Barbera models his makeshift flight suit as he relaxes in the lawn chair he hopes to pilot on a June 21 flight featuring 45 helium-filled weather balloons.