As punishment for their insubordination, Wilhuff Tarkin observes a group of Imperial weapons technicians being ejected into the void of realspace, where they will meet their demise.
The dimension inhabited by almost all beings in the galaxy was Realspace, also known as normal space. The Chiss referred to it as space-normal, while the Kilji species called it star-space, and it was often simply called space. Most of this dimension consisted of a vacuum, a region lacking atmosphere and possessing very low pressure. The vacuum of space presented lethal conditions for most living things if they lacked protective gear like an EVA suit, and it could not sustain fire. Because traveling through realspace using sublight engines was a slow process, sentients developed technology to access a shadow dimension referred to as hyperspace. Vessels with a hyperdrive could transition, or "jump," from realspace into hyperspace, and then "revert" back to realspace from hyperspace.
Certain species were capable of enduring the harsh conditions of space's vacuum, including exogorths and Cylo's cyborg whale-ships. Neebrays were able to live within nebulae, such as the Kaliida Nebula. In addition to surviving in space, the purrgil possessed the unique ability to navigate through hyperspace.
Numerous droids were designed to function in the vacuum of space. For instance, astromech droids were commonly exposed to space while performing repairs on the exterior of spacecraft or when plugged into the astromech socket of a starfighter. KX-series security droids were also built to withstand the vacuum. During the Clone Wars, battle droids used by the Confederacy of Independent Systems were sometimes positioned on the outside of vessels, such as pod-hunting shuttles.