A Lake Elsinore man hoping to become the first person to fly across the United States using only solar power set off on his journey from this eastern Riverside County desert town. After two aborted takeoffs, Eric Raymond, 33, caught the thermal winds he needed to reach an optimal soaring altitude and then headed due east, the pilot's spokesman, Jack Whitehouse, said. Raymond hoped to travel 206 miles on the first leg in his homemade craft, the Sun-Seeker, and land in Carefree, Ariz., 20 miles north of Phoenix, Whitehouse said. But he fell ill and set down at Quartzsite, Ariz., just east of the Colorado River. Whitehouse attributed the illness to fatigue from preflight preparations.