BONNEVILLE SALT FLATS, Utah USA — They are truck drivers, salespeople, computer workers, doctors and accountants. They also are kids at heart and love to shoot high-power rockets thousands of feet into the air.

About 300 rocket hobbyists gathered on Utah's Bonneville Salt Flats on Thursday to open a four-day national convention and launch hundreds of rockets, including some 18-foot monsters and scale models of Patriot and Exocet missiles. Some are designed to climb 25,000 to 35,000 feet at 1,000 mph.

"Bigger boys, bigger toys,'' said Ron Freiheit, an Owatonna, Minn., music-products manager who was preparing to launch a two-stage, 9-foot-long rocket 20,000 feet above the desert.

Neil Davis of Piscataway, N.J., said: "It's good to get out here with a bunch of rocket geeks.'' A thousand weekend spectators were expected to attend the 17th annual Large and Dangerous Rocket Ships launch. 

Sponsored by the Orem-based Tripoli Rocketry Association — one of two national rocketry groups — the event is open to the public. Most of Thursday morning's initial volley of 18 rockets descended gently on parachutes — some toward the crowd of spectators. One rocket's parachute failed to deploy. It became what the rocketeers call a "giant lawn dart.''

Retired Army Lt. Col. Frank Hunt — an adviser to the Utah Rocket Club — builds serious rockets as well as "odd rocs,'' which are rockets placed inside stuffed toy elephants, alligators, Army eagles and other animals.

"I'm the only one who has a three-legged rubber chicken that flies,'' Hunt said. Why spend hundreds to thousands of dollars a year building and igniting rockets?

"When you are a kid, your eyes light up when you see a rocket go off,'' said Hunt, a Fruit Heights resident who has launched thousands of rockets. "You can see it, you can smell it, and you actually can taste it. The excitement is still there when you're a grandpa like me.''

Orem resident Bruce Kelly, president of the Tripoli Rocketry Association, observed: "A lot of these guys are pyros. What can I say? They like the fire, the smoke and the noise.''

Despite that image, "People in this hobby have day jobs and are into Cub Scouts and kids and are normal people. They're not from Montana,'' said Stu Barrett, a Redmond, Wash., software writer.

At least one rocketeer was from Montana: Dale Emery, a Billings doctor whose 31-inch rocket climbed 2,500 feet. It was the smallest of 10 rockets he brought.

"My wife won't let me fly planes, so this is as close as I come,'' Emery said.

"It's a good way to get your aggressions out,'' said Utah Rocket Club President David Sadler of Sandy. "If you are angry at your boss, you can imagine him on board and hope it CATOs — that's catastrophic failure.''

Davis said he knew one rocketeer who built a rocket "with a representation of his ex-wife on the nose cone.''

In other politically incorrect rocketry, the event's official T-shirts depict a woman, clad in a halter top and cutoff shorts, leaning against a V2 rocket and asking, "Your pad or mine?''

Sadler denied rocketry is a phallic-symbol, guy thing and said: "My wife has a rocket bigger than me.'' He said women are responsible for about a fifth of Utah Rocket Club launches.

Hunt's wife, Dot, was prepared to launch a high-power rocket, hoping to become the first woman in Utah to earn a Level 2 certification from the National Association of Rocketry, the other national group. The certification — the middle of three levels — will allow her to buy high-power rocket motors.

A grandmother and retired Sunset Elementary teacher, Dot Hunt hooked her family on rockets after taking a Weber State University aerospace class.

"You get the fever after awhile,'' she said. "You're as young as you feel, not as young as you look.'' Frank Hunt said safety is paramount, and certification is required for high-power rockets and those who launch them. Davis said he knows of no fatality during his years in rocketry.

"If you make your own motors [rather than buy kits] you're likely to have a finger missing,'' said Hunt.

"I've seen two rockets hit vehicles,'' Sadler said. When the parachute failed to open, one rocket plummeted 3,000 feet and "impacted the tailgate of my Jeep Cherokee. It put a ding in it. We make them out of cardboard, paper and plastic so they'll just crumple rather than penetrate.''

Several dozen tripod-like launch stands were set up on the salt flats. Rockets were aimed north into restricted Air Force airspace. Some drifted, prompting Salt Lake City resident Randy Hintze, a launch controller, to announce over a loudspeaker: "Heads up!''

Tripoli evolved from a high-school science club founded in Pennsylvania in 1964. It was named Tripoli because it involved students from three cities and was financed partly by donated old gold coins a member's father got in Tripoli, Libya.

Rocket launches are planned from 8 a.m. to 5 p.m. today and Sunday, and 8 a.m. to midnight Saturday. To reach the site, leave Interstate 80 at Bonneville Speedway exit 4, east of Wendover and 115 miles west of Salt Lake City. Proceed five miles until the pavement ends, then drive onto the salt flats and follow rocket-shaped signs about five more miles.