C.I.T.U.
(sigh-too)
Centrifuge Interface Transfer and Utilities
Spacecraft Tunnel
Leonard J. Holmin
United States of America

Allows shirtsleeves crew transfer and uninterrupted utility lines between a despun base block module and the center of a revolving human spaceflight habitat. Applications could include an improved swivel conduit, as for an industrial spray hose.

Figure One shows overhead view of tunnel structure and mechanism for an exploration vehicle application.

Video demonstrates with crude model the key principle of radial bending of the BELLOWS joints to allow revolutions parallel to habitat wheel having a planetary motion to produce centrifugal force via its orbit.

Rigid TUNNEL segment is hermetically mated between two modules, revolving and despun, via flexible BELLOWS joints (Figure One), made of reinforced rubber or epoxy, or flexible metal, etc. (Industrial BELLOWS joints of welded metal might be scaled up for application to space environment.)

CRANK segments are supported inside BELLOWS by offset bearings so that TUNNEL is eccentric. TUNNEL could be cast and milled from one block of metal so that TUNNEL, gear teeth, utility anchors or manifold fixtures are integral.

TUNNEL makes a planetary motion, driven and synchronized by gear rings. BELLOWS joints laterally deflect parallel to radial position of TUNNEL to follow it as it makes an orbit, somewhat like the wrist motion of a lasso rope. Flexible BELLOWS joints do not rotate but rather revolve and bend at each compass point (see Video).

Utility lines, wet and dry, make a parallel bending and revolving motion with CITU. Inboard lines, inside cabin and anchored along the TUNNEL walls, include moderate voltage electrical and data cables, air ducting and plain water plumbing, accessible in shirtsleeves. Outboard utility lines, anchored along the outside of CITU and its protective layers, include high voltage electrical and power mains, cryogenics, fuels and toxic fluids, and coolant, accessible via spacewalk. Plumbing may be flexible hose or rigid pipe having flexible joints. Utility lines may be connected directly to manifold fixtures integral to the TUNNEL ends.

CITU allows the habitat wheel to be fully mated and connected to its despun base block, in spite of its own revolution.

Sliding shaft seals at TUNNEL ends may provide backup for the BELLOWS, though the BELLOWS provide a true hermetic seal, and there are hatches at each end. A center tunnel liner or axle truss may be equipped with handrails and lights for safe and easy float-through transit by crew. Eliminates sync and re-dock airlock means from old artist’s concepts to transition to and from the habitat hub, which would never provide uninterrupted shirtsleeves crew transfer nor permanently connected utility lines used in a spacecraft.

A very large embodiment (not shown) may include a hub and axle structure providing multiple utility bundles and transfer tunnels, and even conveyance (“elevator”) shafts and large bearings to unite a substantial revolving artificial gravity habitat and resource complex to a despun microgravity complex that provides a command island block, power, propulsion and maneuvering blocks, docking, spacecraft hangaring and scientific and technical instruments bays.