The Sword of Terra is a Colossus class super weapon powered by a zero point reaction engine capable of generating (for a brief time) the energy output of a single stellar mass through its focusing array. The energy of the reactor is focused into a single main weapon, rendering it incapable of ship to ship combat, but given sufficient time its has the capability of unleashing massive energy based attacks on stationary targets, including planets.
Research on the development of the Sword of Terra was conducted in orbit of the planet Mictlan, a penal colony used to house the breakaway human claris sub-species, and later the humans who chose to the support the Skiron Interstellar Hierarchy. The vessel itself was constructed at the Sirius fleet naval yards. The Sword was used most notably in the destruction of the Tyrum homeworld of Byrum and was the principle agent in that species ultimate extinction. Use of the Sword was among the causes resulting in the Terran-Florian war. During the War in Heaven, the Greater Terran Union would use the weapon to destroy the Xani colony world of Xurt, and to later cleanse their homeworld of Core and its moon Boundary of all sentient life.
On top of it's obvious military applications, the Sword of Terra also found civilian use for some of humanity's more grandiose engineering projects. Namely, the construction of the Ring World in the Al-Waha (Oasis) system. As part of the early stages in their grand effort at stellar engineering, the Sword destroyed all the worlds and moons in the system, resulting in a massive debris field of more manageable sized materials that were collected, processed and forged into the components of the massive ring world. The fact that a weapon of such unimaginable destruction could be turned to such creative purposes was the subject of much discussion in philosophical circles and was hailed in Union propaganda as proof of the ingenuity and flexibility of the human mind.