Umbilical cable

An umbilical cable or umbilical is a cable and/or hose that supplies required consumables to an apparatus, like a rocket, or to a person, such as a diver or astronaut. It is named by analogy with an umbilical cord. An umbilical can, for example, supply air and power to a pressure suit or hydraulic power, electrical power and fiber optics to subsea equipment and divers.

Spaceflight applications

Rockets

Umbilicals connect a missile or space vehicle to ground support equipment on the launch pad before launch. Cables carry electrical power, communications, and telemetry, and pipes or hoses carry liquid propellants, cryogenic fluids, and pressurizing and purge gases. These are automatically disconnected shortly before or at launch.

Umbilical connections are also used between rocket stages, and between the rocket and its spacecraft payload; these umbilicals are disconnected as stages are disconnected and discarded.

Space suits

Early space suits used in Project Gemini in 1965 and 1966 employed umbilicals to the spacecraft to provide suit oxygen and communications during extravehicular activity (EVA). (Soviet cosmonaut Alexei Leonov performed the first EVA using a self-contained oxygen backpack, and thus did not require an umbilical.) Later designs (first used on the Apollo program lunar EVA in 1969) did not need spacecraft umbilicals, instead employing backpacks for self-contained oxygen, electric batteries, and radio communication.

Subsea applications

Subsea umbilicals are deployed on the seabed (ocean floor) to supply necessary control, energy (electric, hydraulic) and chemicals to subsea oil and gas wells, subsea manifolds and any subsea system requiring remote control, such as a remotely operated vehicle.