In Bk 2 combat, I'd say that sandcasters were never conceived as point-defense weapons; they're more akin to a smoke screen. It's an active defense inasmuch as someone needs to fire the sandcaster, but after that it's a passive defense as long as your vessel remains close to it and it hasn't dispersed. The actual mechanism that turns a 50kg can of tiny particles into a cloud that doesn't immediately disperse doesn't really concern me; in any case, unless I'm misreading the rules, the can has more than 15 minutes to do it.
In Bk 5, however, it is implied that sandcasters are some form of point defense weapon:
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- "Screens are passive ... as opposed to defensive weapons such as sandcasters ... " [p31]</font>
- "If a weapon scores a hit, then it must penetrate first the defensive weapons and then the passive defenses. Defensive weapons (sandcasters &c) ... must be allocated against the hits of specific batteries." [p40, emphasis added]</font>
In addition, there is no mention in Bk 5 of sand hanging around after it's been fired, which implies that it is not being used as in Bk 2, and also makes sense given the Bk 5 vectorless combat system.
Obviously it's impossible for a defensive weapon to be fired against an enemy weapon that has already scored a hit, so there must be some chronological reordering going on for the sake of playability. That is, perhaps incoming fire from energy weapons is assumed, and so sandcasters are fired as a matter of course. (Bad analogy perhaps, but in BSG the capital ships seem to do a lot of aimless, high-volume slugthrowing on the off chance that it will hit an approaching missile or fighter.)
I looked to Striker for some hints there, and in Striker Bk 1, Rule 27 there is a discussion of the effects of obscuring smoke and aerosols on laser weapons fire, along with an interesting passage concerning "laser sensors", which:
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- "... will detect the fact that a laser is contacting the vehicle. [If a particular roll is made,] ... the unit firing the laser is automatically spotted. In addition, if the target vehicle is equipped with anti-laser aerosols, it may immediately discharge them if contacted by a non-weapons laser [ie a spotting laser]. Laser sensors will not be able to discharge aerosols against a weapons laser; the laser does its damage before the sensor can react." [p43, annotation added]</font>
While I hesitate to transpose Striker ground combat rules to Traveller starship combat, it's worth noting that the Striker coverage of the issue is quite sensible and specific with regard to the usage of anti-laser "chaff" and the manner in which incoming laser fire is detected.
In summary I'd say that the Bk 2 sandcaster is a different animal than the Bk 5 sandcaster. I see no issues with the use of sand in Bk 2 combat, as long as I can swat aside the (dull, for me) issue of how a sand cloud of sufficient size and density is actually formed. In Bk 5, the sandcaster's described role as a defensive weapon is somewhat problematic - an artifact perhaps of having to keep sandcasters in the game while dropping almost all ship movement. In any event I'd suggest that Bk 5 sandcasters are used quite differently than in Bk 2, and that perhaps Striker can offer some clueful details.
