History

At first the only gravity available aboard spacecraft was based on rotation or acceleration.   Early in Era-1, scientists in the Planetary League discovered a rare material that allowed limited manipulation of gravitational fields.  Gravitonium is generally found in the vicinity of black holes, and neutron stars, making it both rare and dangerous to collect.

During Era-1, as more sources of gravitonium were discovered, Gravity Generators for ships and space colonies became a practical reality.

Also early in Era-1, the art of gravity manipulation made possible the manufacture of Inertial Compensators,  which allowed crewed ships to accelerate at much faster rates without harming those inside.

Midway through Era-1, the Gravity Satellite was invented which allowed the gravitational field of any planet wealthy enough to afford the large amount of gravitonium necessary to be adjusted.

The cost of artificial gravity gradually came down as sources of gravitonium were discovered.  The most major advance in availability and cost for artificial gravity came in Era-3, when scientists in the Galactic Republic discovered an effective means of synthesizing gravitonium.