An air force general has run afoul of Congress for granting clemency to a convicted sex offender without any public explanation, the latest case to raise fundamental questions about how the military justice system handles sex crimes.

The case is the second this year in which a three-star air force general has raised lawmakers' hackles by effectively pardoning an officer found guilty of sexual assault, a crime many experts see as a growing problem in the military.

This time the general is a former astronaut who has served as a role model for other female officers as she climbed into the upper ranks of the air force.