Missile Frigates are really nothing more than a retro-fitted Merchant
Cruiser.  They maintain the same speed and range of the Merchant but can
carry twice the firepower.  Commanding a Frigate means that you cannot
take advantage of much of the additional starship equipment available,
but their combat advantages make up for that.  The Missile Frigate is
the only ship outfitted to carry the awesome Photon Missile.  These
weapons of destructions can turn StarPorts into space junk in short
order.  The Photon Missile was also used effectively in the Trantorian
conflict to totally destroy the enemy's home planet.