:: Star Trek Media Online

There are two types of photon torpedoes, the first type contains six slugs of deuterium which are fired at corresponding slugs of antideuterium at detonation, the explosive energies then created are briefly held by a containment field, and then released. Although the torpedo could coast indefinately after launch, it has a maximum range of 750,000 km due to stability limits of the anti-matter containment unit.

The second type of torpedo is the one which Starfleet currently use. This torpedo has a maximum range of 3,500,000 km. In this torpedo thousands of tiny packets of matter and antimatter are held in suspension by powerful magnetic fields. This device also has a variable yield.

Until launch these packets are held in separate regions of the torpedo, as a safety precaution. Upon launch the packets are mixed, although they don't come into contact. At detonation the fields holding the matter/antimatter apart collapse, and the torpedo explodes. The maximum payload in a standard torpedo is 1.5 kg of antimatter and 1.5 kg of deuterium. This payload would cause an explosion of 18.5 isotons. The standard torpedo casing used by Starfleet is 2.1 x 0.76 x 0.45 m and weighs 247.5 kg (before loading)

Torpedo Propulsion

The torpedo can sustain warp velocities due to it's internal multi-mode warp-field sustainer system. This system is not a true warp-engine due it's small size. It is only intended as a matter/antimatter fuel cell, which uses the field sustainer coils to 'grab' and hold a 'hand-off' field from the torpedo launcher in order to maintain the torpedo's velocity if launched at warp. Due to the small size of the matter/antimatter cell the torpedo can only travel 0.75c faster than the launch velocity. The torpedo steers by differentially constricting the sustainer exhaust grills.