 Travis and the teenagers realize the device has numerous practical uses, but it is also a dangerous weapon.They decide to use the squeezers to power a spaceship and plan to arrive at Mars ahead of the slower traveling American and Chinese missions already in transit, and to be available should Jubal's prediction of problems with the American drive prove true.They succeed in building the "Red Thunder" out of used railroad tank cars on schedule, and near their shoestring budget of $1 million and take off.