The environment encountered by living creatures (and vehicles) in space; especially a lack of atmosphere and gravity

A mental representation of a particular problem, including initial, final and possible intermediate states

Alternative spelling of space defense

(in an electromagnetic coil) The ratio of the volume occupied by the wire in the winding, or the iron in the core, to the total volume of the winding or the core

Any defensive measure against an attack by missiles etc while in space

Communication between space vehicles, or between such vehicles and a base on Earth, the Moon or other planet, especially when using high-frequency radio waves

A blanket made of a plastic material covered with a reflective metal agent; designed to reduce heat loss from a person's body following trauma, or used on the exterior of a spacecraft for thermal control.

The guidance operations needed to launch a spacecraft into orbit or space, navigate in space, and return to Earth or some other body

(mathematics) any curve in three-dimensional space; includes any plane curve as a subset

(informal) Space debris.