Copernicus and Galileo had it easy. Those two lived during the middle of the European Renaissance, a time when creativity and curiosity were norms in society. Sure, the church came down hard on their views on where the earth stood in relation to the rest of the universe. But, basically, the church simply disagreed with the details of their argument. (Well, I guess calling someone a heretic is slightly more than disagreeing with someone, but you know what I mean...)
The scientific minds who really had rough run-ins with the church lived during the fourth century, under the moral guidance of Augustine, the Catholic archbishop of Hippo. At that time, science was a sin, as Augustine likened inquisitiveness to a form of lust. Not a "lust of the flesh", but more of a "lust to find out and know". According to author, William Eamon, Augustine saw no difference between people-watching at the circus or the piazzas and enduring the rigors of scientific study. Check out the rest of Eamon's fascinating analysis here.