Talk:Tactical Jammers/@comment-46.223.1.77-20141016174847/@comment-25787218-20150118021402

Asteroids do not stack. From page 20 of the core rulebook (and the revised text from page 1 of the FAQ),

“When measuring range during combat, if the edge of the range ruler between the closest points of the two ships and inside the attacker’s firing arc overlaps an obstacle token, the attack is considered obstructed. Because of this obstruction, the defender rolls one additional defense die during the “Roll Defense Dice” step of this attack.”

The condition of being obstructed is meet when "the edge of the range ruler between the closest points of the two ships and inside the attacker’s firing arc overlaps an obstacle token". There is no text in the rules to suggest you can be obstructed twice. The discussion on the FFG forums also follows this logic.