Why the angle of attack is 40 degrees for shuttle started to reentry I'm a newbie here. Because I am doing an assignment on the Columbia Shuttle Disaster. I need some data for supporting my statement. The shuttle must then tilt upward to present its flat bottom, covered with heat-resistant ceramic tiles, to the upper atmosphere, with the nose angled upward at 40 degrees, the so-called "angle of attack." This angle is critical to the shuttle's re-entry. If it is greater than 40 degrees, the craft could flip over backward from the atmospheric thrust. Less, and it would risk entering the atmosphere too fast, and overheating and possibly melting its aluminum shell. Thus, I wonder how to calculate initial angle for shuttle reentry is 40 degrees? How about the resistance and gravity acting on the spacecraft? And what's the direction of velocity for it enter the atmosphere? Thanks a lot!