The Space Wire protocol is a intra-satellite communication protocol. It allows different components of spacecraft to communicate with each other.

Space Wire is a full-duplex, point-to-point link, operating at 2 to 200 Mbit/s. It uses LVDS signalling for low-power operation and data-strobe encoding for resistance to clock drift.

A Space Wire cable is composed of 4, 28 AWG, twisted pairs, up to 10 m long with a 9-pin micro-miniature D-type connector at each end.

Complex topologies are supported via packet-switched routing.