(mathematics) A measurable space having a unit measure

(psychology) The awareness of the position, size, form, distance, and direction of an object, or of oneself

The utilization of low gravity and/or high vacuum to carry out various processes in space

(physics) The ratio of magnetic induction to magnetizing force in a vacuum

The reconnaissance of the surface of a planet from an orbiting spacecraft.

(astronomy) The reddening of the light from distant stars because of selective absorption and scattering by interstellar dust

(physics) A difference of a quarter of a wavelength between the spatial positions of two corresponding points in a wave

(computing) a parameter (in some file systems) that specifies the storage space required for a new file

Any device that attempts to simulate the environment of space, especially one used to test components of space vehicles

A journey, by a human or robotic spacecraft, into space for a specific reason (normally to gather scientific data)