Also, the Concusion Missile is Guided. The book says about Guided weapons...
Certain types of projectiles, such as guided missiles, may benefit from course alterations after being fired. If a character misses while firing a Guided weapon and if Guided is activated, he may make an attack check at the end of the round. The difficulty of the check is calculated by comparing the weapon's silhouette of 0 to the silhouette of the target (see page 249), and the check's Green Dice equal the weapon's Guided rating. If the test is successful, the weapon strikes the target, and damage is dealt normally.
Guided requires Three Success to activate, unless otherwise specified in the weapon's description. Remember, the Guided effect can activate on its subsequent attacks, representing the projectile continuing to track the target.
"Spoofing" is a countermeasure designed to work against a particular type of projectile, such as flares designed to draw off infrared missiles. Spoofing directly increases the defense of the target against attacks with the Guided quality.