His commitment to nonviolence came through studying the Hindu leader Mahatma Gandhi, his opposition to the Vietnam War was motivated by meetings with the Buddhist monk Thich Nhat Hanh and some of his most profound conversations about faith and civil rights took place with a Rabbi, Abraham Joshua Heschel.

FORBES: Faith as a Bomb, Faith as a Bridge: Building a 21st Century Interfaith Movement

In the past year or so, he has been studying partly through the Internet and with the help of some other clerics.

NPR: Who Is Al-Sadr? A Closer Look at the 'Radical Cleric'

Since the changes the body goes through in zero G are so similar to the ones it goes through as it ages, studying a weightless senior citizen is supposed to shed light on both processes.

CNN: Victory Lap