An event called "Large, Dangerous Rocket Ships" doesn't bring to mind a day of peace and quiet. If nothing else, a field packed with amateur rocketeers blasting things toward the heavens is raucous to say the least. But Sean Lemoine found it all very … zen. "It's very serene out there, just watching the rockets," he says.

Large, Dangerous Rocket Ships is among the world's biggest amateur rocketry events. Some 250 rocketeers from as away as the UK and Argentina gathered on a cracked lakebed in the Mojave Desert, where the Federal Aviation Administration cleared the airspace for miles around. That's essential, because these folks launch rockets capable of reaching 17,000 feet and making Elon Musk smile.

Lemoine's experience with rockets is, well, limited. When he was 10, he spent the summer building a rocket that disintegrated after liftoff. But he heard about the event in 2015 while looking for something quirky to shoot, and figured, "Why not?" Most of the people he met at June's launch, organized by the Tripoli Rocketry Assocation and hosted by the Rocketry Organization of California were engineers or scientists who devote their free time to the hobby. "You think of a rocket as something a child would be interested in, but these people truly appreciate what the rocket is for," he says.

Many camped on the lake bed, separated from the launch area by a line of festive bunting. By 7 am each morning they were lined up to have their rockets inspected. Some were small projectiles built in hours; others were taller than the people who spent months building them. Most looked like rockets, but more than a few models of the USS Enterprise and other iconic ships filled out the fleet.