The Sphere belonged to an advanced race that shed their biological existence and transferred their consciousnesses into artificial bodies thousands of years ago. At some point, their planet was conquered by a hostile alien race—refer by the Sphere as the "Harvesters"—that harvested its core. The Sphere was the sole survivor of its kind and carries the combined intelligence of its entire species. It then traveled across space and encountered other alien races that were also defeated by the Harvesters, and helping them find refuge on a planet and establishing a major resistance against the Harvesters.
In 2016, the Sphere intercepted a distress message and learned of the Harvesters' first defeat at the hands of humanity on Earth. Knowing that the Harvesters would come to exterminate humanity, the Sphere traveled to Earth in the hopes of evacuating humanity and allowing them to join in its resistance. But upon its arrival at Earth's Moon, the humans mistake the Sphere's spaceship as a hostile force (due to Rhea Base's destruction beforehand) and shot it down, causing it to crash in the Van de Graaff crater. The Sphere survived the destruction and was found by ESD Director David Levinson, who opposed the ESD's decision to shoot it down.
When the Harvester Mothership lead by their Queen arrive, the Sphere was taken to Area 51, where it explains its origins and original mission. Knowing that the Queen has become aware of its presence, the Sphere request the ESD to destroy it in order to prevent the Harvesters from acquiring the coordinates of the refugee planet. However, the humans refused and instead plan an attempt to kill the Harvester Queen by laying out a trap. The Sphere was secured in an isolation chamber with Doctors Brackish Okun and Milton Isaacs, and the ESD duplicated its frequency to serve as a decoy. Although the trap succeeded, the Queen survived and assaulted Area 51 for the Sphere. The Queen almost acquired the Sphere until it was finally weakened and killed by ESD pilots using hijacked alien fighters. The loss of the Queen rendered all alien forces around Earth inactive and forcing the mothership to leave Earth.
The Sphere was impressed by humanity's tenacity and victory. In gratitude, the Sphere offered humanity new technology, which includes FTL travel and asked them to assume leadership of the resistance in preparation for a potential assault on the Harvesters' homeworld.