Scientists named our alien attackers the Ixions after one observer called their ships "fiery wheels of death." We do not know what they call themselves. Linguists are still studying Ixion radio transmissions. We do understand some of their technological advancements, such as how their ships achieve light-speed. Our interstellar capability derives directly engine and ship superstructure salvaged from Ixion wreckage.
We also do not know their motivations for their assaults on our planet, but their use of air and ground units suggest their desire to conquer and colonize Earth. Their capital ships possess weapons of orbital bombardment, which they have not utilized to this date.
Their first assault drained most of Earth's combined military resources, and the evidence of that attack still floats in mid-orbit over the Earth. The wreckage of Ixion ships, Earth's destroyed satellite networks, and leftover nuclear material detonated Earth-based missile warheads create an artificial ring system, seen even from the ground as a glittering band spanning the sky.
The only advantage we seem to have is that the Ixion do not use medium or heavy armor units. The construction of their capital ships suggest that the Ixion have weight and space limitations in order to achieve light-speed, allowing them only to bring lighter armor. It is because of this advantage that Earth has managed to remain free after all these decades.
There has been a total of six Ixion attacks on the planet Earth. As we have developed better detection technology over the years the advance warning for each attack improves significantly, as well as our understanding of their technology and tactics. After all these years, our patient struggle and resistance has provided Earth with a unique opportunity to strike back. As of the writing of this article, the combined resources of the human race has produced a small fleet of our own light-speed capable ships, led by our flagship, the Pegasus.
From bodies recovered from crashed assault ships, biologists determined the Ixions to have a trilateral symmetry. They stand upright and possess mammalian traits, being warm-blooded and able to give birth to live young.
Each third of an Ixion body has an independent circulatory system. This means that physical traumas and blood loss does not directly effect the other two thirds of their body. However, their nervous system is integrated, so brain death usually occurs soon after one part of an Ixion dies.
In terms of military strategy, the Ixions physiology allows them to function for a short period of time even after suffering the human equivalent of a mortal wound. Some Ixion bodies appear to possess artificial organs made of some unknown plastic-based material. This also suggests that a wounded Ixion may be able to survive long enough to undergo surgery and transplantation. As a result, a typical Ixion soldier can outlast even the best of our troops by an unspecified amount of time."