TrilogyÂ Omnibus: All three books in one volume.Â After a field trip at the local Challenger Center, JJ Wren and her friends are hand picked by the mysterious Commander Zota to become Star Challengersâ€”sent into the future on special adventures to a moonbase, a space station, and the asteroids. Their mission is to learn high-tech skills . . . and save the human race from an imminent alien invasion!