Grandma Lee tours the California wilderness in a motor home with her Americanized family, teaching them Tai Chi and the ancient Chinese way to deal with modern American life.

When an asteroid threatens to collide with Earth, NASA honcho Dan Truman determines the only way to stop it is to drill into its surface and detonate a nuclear bomb. This leads him to renowned driller Harry Stamper, who agrees to helm the dangerous space mission provided he can bring along his own hotshot crew. Among them is the cocksure A.J. who Harry thinks isn't good enough for his daughter, until the mission proves otherwise.