He came back down in one piece, too - a little dinged up and his steam-powered vessel a little cracked up.

Still, mission accomplished for a guy more daredevil than engineer, who drew more comparisons to the cartoon character Wile E Coyote from his critics than he did to iconic stunt man Evel Knievel.

"Mad" Mike Hughes, the rocket man who believes the Earth is flat, propelled himself about 1875 feet (571 metres) into the air on Saturday before a hard landing in the Mojave Desert. He told The Associated Press that outside of an aching back he's fine after the launch near Amboy, California.

"Relieved," he said after being checked out by paramedics. "I'm tired of people saying I chickened out and didn't build a rocket. I'm tired of that stuff. I manned up and did it."

The launch in the desert town - about 320km east of Los Angeles - was originally scheduled in November. It was scrubbed several times due to logistical issues with the Bureau of Land Management and mechanical problems that kept popping up.

The 61-year-old limo driver converted a mobile home into a ramp and modified it to launch from a vertical angle so he wouldn't fall back to the ground on public land. For months he's been working on overhauling his rocket in his garage.

Sometime after 3pm and without a countdown, Hughes' rocket soared into the sky.

Hughes reached a speed that Stakes estimated to be around 560km before pulling his parachute. Hughes was dropping too fast, though, and he had to deploy a second one. He landed with a thud and the rocket's nose broke in two places like it was designed to do.

"This thing wants to kill you 10 different ways," said Hughes, who had an altimeter in his cockpit to measure his altitude. "This thing will kill you in a heartbeat".

Australian Associated Press