One thousand years ago, when the United States of America did not exist and Oxford and Cambridge were backwaters of ignorance, the light of human reason shone brightly in places like Tunis, Cairo, and Baghdad. During the Abbasid caliphate for much of the 8th through middle 11th centuries, and also sporadically thereafter, tolerance of certain non-Muslim groups was enshrined in law.

He shared some of his favorite memories from the mission.

The second shuttle disaster changed the landscape for America's space agency.