I don't know, but this:
$Name: FuraFlare
@Laser Bitmap: Blue_Herc_Glow
@Laser Glow: prometheus_glow
@Laser Color: 155, 155, 255
@Laser Color2: 5, 5, 85
@Laser Length: 0.5
@Laser Head Radius: 2.5
@Laser Tail Radius: 2.5
$Mass: 800.0
$Velocity: 30.0
$Fire Wait: 0.50
$Damage: 0
$Blast Force: 0.0
$Inner Radius: 0.0
$Outer Radius: 0.0
$Shockwave Speed: 0.0
$Armor Factor: 1.0
$Shield Factor: 1.0
$Subsystem Factor: 1.0
$Lifetime: 0.02
$Energy Consumed: 0.0
$Cargo Size: 2.0
$Homing: NO
$LaunchSnd: 99
$ImpactSnd: 99
$FlyBySnd: -1
$Rearm Rate: 5.0
$Flags: ( "countermeasure" "Spawn FuraFlareChild, 4" )
$Icon: none
$Anim: none
$Impact Explosion: Kayser_impact
$Impact Explosion Radius: 5.0
$spawn angle: 3
$Countermeasure:
+Heat Effectiveness: 1
+Aspect Effectiveness: 1
+Effective Radius: 300
Seems to work just fine (and it looks great).
Granted, it's a CM, but I don't think that missiles should act any diffrent.