A boy and his family travel throughout the galaxy via the Tomorrowland Transit Authority. An animated space adventure featuring the Callisto family whose home is a spaceship called the Stellosphere. The Callistos work for the Tomorrow Transit Authority. The family consists of Miles, the key character in the series; his elder sister Loretta; and their parents Phoebe and Leo who are both scientists. The family sets out on an adventurous journey meeting new people on their way.