The Gabby and Maddox adventure series continues in this new chapter book when our siblings join the Children's Astronaut Program while visiting their grandparent's in Florida. Shortly after liftoff on a routine trip to the Space Station, something goes horribly wrong. Gabby and Maddox find themselves drifting deep into outer space on a ship with no power. Meanwhile Lieutenant Lenny and his staff at Space Command do all they can to aid the siblings. Lost and helpless in outer space, Gabby and Maddox are rescued by a purple alien named Spark from the planet Ubatuba. Shortly after their arrival on the alien planet, the children are asked to help solve a mystery that baffles the Ubatubans. Gabby and Maddox quickly learn not everything is what it appears. Will Gabby and Maddox be able to solve the mystery? Will Spark keep his promise and help the children get back home? Australian friends Cody and Bindi are launched on a rescue mission to save their young American friends, but will they make it in time? Join Gabby and Maddox on this wild, new, space adventure.