Operation REJUVENATION

Operation REJUVENATION, or as it colloquially known, "Rejuve", was a massive effort on the part of the post-Great War United Nations Space Command and the surviving Unified Earth Government to reestablish connections with far-flung colonies and expand Human influence in the Orion Arm. It promoted massive repopulation drives and colonial efforts, using the valuable information stored in the Colonial Administration Authority's old planetary database to create new colony worlds on suitably habitable worlds. During this gigantic campaign, scout ships were sent out to research possible sites for new colonies relayed by the Sangheilian diplomacy service, and ONI was responsible for sending expeditions to worlds with known Forerunner installations in hopes of salvaging valuable recreative technology to aid in their terraforming efforts.
==Origins==
Operation REJUVENATION was originally proposed in part by Fleet Admiral Terrance Hood, in conjunction with several other high-ranking UNSC officers and some surviving UEG politicians. It was based upon the plans laid by one Nigel Espitalier, a South African survivalism theorist who did extensive studies during the late war on possible solutions to regrowing the Human population in a close-to-extinction situation. The Espitalier Plan, as it was first known, called for the immediate focus on reconstructing Earth before sending out any more colonial expeditions. Without a solid foundation with which to rebuild and recolonize, Espitalier assumed, any and all attempts to reconstruct Human influence would be weak and would ultimately fail. With the UEG's communications with any extrasolar colonies in shambles, both High Command and the Council approved of the plan, which was presented by Lord Hood. There was no way of knowing if any of the colonies outside the Sol System still survived, so restoring Earth was a key priority. Under Hood's guidance, all remaining terraforming units in and around Sol were transferred to the motherworld, where they were immediately tasked with restoring any and all destruction caused by the Covenant. Obviously, some damage, such as the rift left by the opening of the Ark portal, could not be repaired, but thanks to a recent technological breakthrough aided by a Sangheilian gift, a great amount of previously-glassed terrain could be restored to something like its previous state.
After several years of restoration, Earth began to resemble a fraction of its past self, and it was deemed time to expand efforts to encompass the entire Sol System, utilizing all remaining resources in an effort to rebuild a base of power. The asteroid belt and the Jovian and Saturnine moons were swarmed with miners hoping to strike it rich, and raw materials soon began to flow back to Earth and her nearby daughter-colonies. Despite weak protests by some natural-preservation movements, many of the asteroids were strip-mined into husks, while Luna's already-diminished supply of minerals was nearly exhausted. 
In time, with industry going full-throttle, the UNSC was able to build up its strength enough to begin sending out ships of their fleet to colonies that they believed had survived the war. Frigates were repurposed as heavily-armed scout ships, dropping into a system, sending several Pelicans laden with Marines down to the surface of any planet with Human lifesigns, and storing all relative data in their navigation computers. Dozens of surviving colonies were rediscovered in this manner, all with their own special resources to bring to the table. Some, those not discovered by the Covenant had their full populations, people who were willing to work to rebuild Humanity. Others had giant untapped deposits of crucial resources on their surfaces, while still others maintained their relatively-intact infrastructure.
Some worlds still considered critically important, but still technically uninhabitable, such as Reach, were the test sites of new terraforming processes the UNSC had been granted by the leaders of the Separatists. Research bases were set up on the cooling surface, and within a few years, several highly-effective methods were discovered and applied with great effect on worlds that had only been partially glassed. 
In 25XX, Chancellor Reiko Hahn-Mueller announced that Earth and her surviving colonies had a new priority: to rebuild what was lost. Despite the fact that this had already been the aim of the Espitalier Plan, her speech galvanized the remnants of the once-formidable human sphere of influence into working together towards the common goal of man. Operation REJUVENATION was officially announced, a revised and elaborately-planned version of Espitalier's rough draft. The Operation called for several key phases in its timeframe, all of which worked toward its ultimate goal: to have Humanity's reach restored within the century.
==Phase One==
==Phase Two==
Phase Two involved sending out joint military expeditions to worlds with known Forerunner installations on them, in hopes of recovering advanced salvageable technology. Such technology would be applied to Human research and development, advancing technological progress by leaps and bounds, or so it was hoped. There were literally scores of worlds on record as having a major Forerunner presence, and many frigate-based scouting parties were sent out to further analyze the effectiveness of anything found in the ruins.
Several of these expeditions resulted in prolonged and hazardous treks into the wilderness because of still-active defense grids or confrontations with massive amounts of Sentinels controlled by insane artificial intelligence constructs. For the most part, however, most investigations were rather tame, and turned up little, if any, actual results. One planet, however, held a large cache of what were apparently mothballed Forerunner world-altering machines. Upon further inspection, it was found that a great deal of them still functioned, and could be activated by Human touch. High Command immediately ordered them shipped back to Reach, where they were tested to amazing effect, clearing surfaces that would have been considered unable to be restored in only a matter of months.
The most astounding discovery of all, however, was a device known only by its codename: PRELUDE.