“Zero Gravity” follows a diverse group of middle-school students from San Jose, Calif., who compete in a nationwide tournament to code satellites aboard the International Space Station (ISS). Seen through the wondrous eyes of three young students and their first-time coach, they each take an intimate and personal journey to space as their team grows from amateur coders to representing California in the ISS Finals Tournament — the culmination of a summer-long adventure that sees their incredible accomplishment performed by astronauts in orbit.