Vacations and summertime, when he isn’t teaching A.P. or BC Calculus, Steve Feldman, of Goodwin House, skydives. His team, Mass Defiance, recently won the National Championships of four-way formation skydiving, held in Perris Valley, California. “Some great combinatorics math problems,” are what Steve calls the strategies to engineer more efficient ways moving from one formation another. “When do you reach terminal velocity?” asked one student at assembly as the School watched a film summary of the team’s winning rounds. Steve has visited physics classes to talk about projectile motion and acceleration due to gravity within a particularly exciting context.

The team’s task is to jump from the plane and immediately try to cycle through five formations within 35 seconds, when the team members break contact, and separate from each other far enough to open their parachutes for the rest of the fall to the ground.

Steve is the videographer this year. He jumps with or just after the team; a camera is mounted in his helmet, and he records the formations from above as they happen. As soon as the team hits the ground, Steve gives the video of the jump to the judges, who immediately judge the speed and accuracy of the formations.

“It’s something I always wanted to do,” Steve answered one student who asked how he got interested in this athletic pursuit. After college, Steve moved to California with his equally interested college friend, and both pursued certification. Team members practice their skill — connecting and reconnecting in set formats, while falling through the air — in a large wind tunnel. One such wind tunnel will soon open relatively close by, in Nashua, New Hampshire. Steve’s teammates are an eclectic group: a chief technology officer, an engineer at MIT, an owner of a plumbing construction company and a Harvard grad student.