MAPLE ISLAND, Minnesota USA — For several hours Saturday, a muddy dirt road through snow-covered farmland was turned into something completely different: A launching pad for rockets.

One by one the models blasted into the sky — more than 30 in all — as hobbyists gathered for a launch just northwest of Austin, held in conjunction with the National Association of Rocketry's national convention an hour's drive away in Rochester.

"My most favorite part about the launch is having it go off in the air," 7-year-old Ryan Glascock said excitedly after he and his father, Don, completed their first-ever rocket launch together.

Andy Limper of Rochester prepares his rocket for launch at the National Rocketry convention Saturday in Maple Island.

Rockets with names such as "Praying Mantis" and "Paid Assassin" launched on a day when people were thinking about the history of model rocketry, whose 50th anniversary as a hobby was marked at the convention at the Kahler Grand Hotel. At the same time, the Rochester event marked the first time a national model rocketry convention has been held in Minnesota in 40 years.

In between rocket flights, launch director Andy Limper of Rochester put the hobby into perspective.

Forty years ago, Limper said, the most powerful model rockets had "C" motors. With each one-letter increase representing a doubling in power, the most powerful rocket launched Saturday had a "K" motor, which falls far short of the stars, but still has power Limper said would have been inconceivable to hobbyists 40 years ago.

Rockets brought for launching Saturday ranged from the relatively small, roughly a foot or two for a rocket like Glascock's, to larger rockets like a seven-footer owned by 53-year-old Craig Knippel of Austin.

Knippel, who traced his interest in model rockets back to the ninth grade, said he's drawn to model rocketry not just by the people and the short-but-sweet thrill of launch and recovery, but by the smell of rocket fuel.

He wasn't the only one re-living memories as rockets crackled into the sky Saturday afternoon.

Memories were rekindled in Don Glascock of rockets launched by his brother during their childhood in New Mexico. After his successful blastoff, he talked about possibly launching more rockets in the future with his son.