High-schooler Grover Beindorf and his younger sister Stacy decide that their parents, Janet and Ned, are acting childishly when they decide to divorce after 18 years of marriage, so they lock them up in the basement until they'll sort out their problems.

Andie Bergstrom, an astronaut eagerly awaiting her first trip to space, runs a summer camp for teenagers with her NASA-employed husband, Zach. One night during an engine test, Andie and four teenage campers are accidentally shot into space. Together, the group -- which includes Kathryn, a pilot-in-training, and Tish, a ditz with a perfect memory -- must work together to operate the spacecraft and return home.