Mark Whorton works on guidance, navigation, and control systems for spacecraft and launch vehicles at the NASA Marshall Space Flight Center in Huntsville, Alabama. He received a Ph.D. in aerospace engineering from Georgia Tech, teaches Christian apologetics at his local church, and is also the author of Peril in Paradise: Theology, Science and the Age of the Earth.
Hill Roberts holds a Master's degree in physics from the University of Alabama and serves as a chief scientist for a Huntsville-based aerospace research company. He also founded the Lord, I Believe ministry (LordiBelieve.org) for teaching people the rational basis for faith in God's existence and has lectured extensively on Christian apologetics in the United States and Russia.