Early shield-burster missile prototypes were developed prior to the outbreak of the Terran-Kilrathi conflict in 2634 by both the Confederation and Kilrathi subject races. The primary obstacle lay in the polarity shift frequency of phase shields, which could simply be increased at time of impact to prematurely detonate the torpedo before it penetrated the shield. Although speculative exercises were conducted by ConFleet in 2622 to experiment with the feasibility of such a weapon, the concept caught little interest and Fleet doctrine continued to stress massed heavy weapon barrages at the start of the war.
Kilrathi leaders were more receptive. Searching for a technological advantage to trump the Confederation's material superiority, they discovered records of the Panama war games from a captured human colony on Fawcett's World and set their subject races to work on developing a practical model. Development was slow, despite urgent pressure from Crown Prince Gilkarg nar Kiranka, but by mid-2634 working prototypes had been completed, which were quickly rushed into production to see action at McAuliffe later that year.
One of the main deficiencies of these early torpedo models was the need for the firing ship to remain stationary during the acquisition process. The other was the inability of capital ships to launch torpedoes without shutting off their own shields, the heavy shielding interfering with the necessary acquisition and lock process. Though the former would eventually be corrected, torpedo runs would still require pilots to fly straight and steady during a lock period of up to thirty seconds. Records showed that the latter remained an issue till late as 2654, with capital ships still powering down shields before launching torpedoes at that time.
A chart of recorded torpedo types in use during the 27th century is seen below.
It should be noted that the Proton Torpedo, a popular civilian weapon, is not a true torpedo in the sense defined by this article.