This unintended voyage took nearly three years, during which several mutinies aboard took the lives of over half the passengers and crew. Miraculously, the damaged Marsten Drive dropped the ship back into realspace near a star with a marginally-habitable world. The survivors coaxed the crippled ship into orbit and clawed out a rough existence for themselves for over a century, finally reaching a state of technology and society that allowed them to successfully petition for Member status when they were discovered by the science ship Isaac Asimov just three years before the Republic-Empire War.
Because the original leaders of the dissident expedition were killed during the shipboard mutinies, we will likely never know what kind of society they intended to build. It is to the credit of their descendants, however, that the people of Necessity have already become known throughout the Republic for their unity, inventiveness, engineering prowess, and relentless determination to succeed at any task set before them. This is understandable, for on Necessity, those lacking such traits are unlikely to survive.
Necessity is a cold world, resembling what Terra must have been like during the last Ice Age. Fossil records indicate that, like Terra's, Necessity's climate has undergone cyclic changes over tens and hundreds of thousands of years. Currently Necessity is believed to be on an upswing, tending toward warmer weather over the next several centuries at least. Xenobiologists and paleontologists from various institutes and universities throughout the Republic and former Empire are studying Necessity's rich fossil specimens, some almost perfectly preserved in ice, with considerable interest. Some fossil evidence suggests that there may have been a stone- or early metal-age society of sentient or at least pre-sentient amphibians on Necessity, which was destroyed when the currently-receding ice age began. This, combined with the discovery of former Imperial outpost Eyan, lends considerable weight to the theory that life tends to evolve toward intelligence, and that more alien civilizations do in fact exist throughout the universe.