Pegasi Delta

Pegasi Delta is a small world in the 51 Pegasi-B System. The surface of the planet was made of red rocks and sand. Orange dust permeated the sky. It had seas that were unusually rich in Deuterium and Tritium, which were usable in the reactors of Covenant ships. The world orbited around a faint yellow sun.

During the Human-Covenant War, the Covenant forces constructed a massive refinery on Pegasi Delta. With its close proximity to UNSC space, Pegasi Delta became a massive forward resupply and refueling line for the Covenant ships making incursions in UNSC space.

History
In 2545, the UNSC sent in 300 Spartan-III super-soldiers from Beta Company to destroy the refinery in Operation: TORPEDO. They successfully destroyed the refinery, crippling the Covenant supply lines, but with 298 of the 300 Spartans of Beta Company were killed. Because of this, Lucy-B091, one of the two surviving spartans, was so shocked from the incident that she became mute.

Trivia

 * Pegasi Delta is the UNSC designation for the Covenant colony. It is likely that the Covenant had their own name or designation for it, unrelated to that used by the UNSC.
 * Tom-B292 and Lucy-B091 were the only two Spartans that survived the explosion.