Noun
inertial space (plural inertial spaces)
(mathematics, physics) A coordinate system (or a frame of reference) defined with respect to the distant stars, whose relative positions do not change over reasonably long periods of time
Alignment with the Earth's axis is the only direction for which the gyroscope's spinning axis can be stationary with respect to the Earth and not be required to change direction with respect to inertial space. Source: Internet
The UVS was mounted on Galileo's scan platform and could be pointed to an object in inertial space. Source: Internet
It does so, not by sensing the Earth's magnetic field, but by using inertial space as its reference. Source: Internet
The logical inference is that just like gyroscopes, the angular momentum of all celestial bodies is angular momentum with respect to a universal inertial space. Source: Internet