TransHab was a concept pursued by
NASAThe National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
to develop the technology for expandable habitats inflated by air in space. Specifically, TransHab was intended as a replacement for the already existing rigid
International Space StationThe International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
crew
Habitation Modulethumb|right|250px|ISS Habitation moduleThe Habitation Module for the International Space Station was intended to be the Station's main living quarters designed with galley, toilet, shower, sleep stations and medical facilities. About the size of a bus, the module was canceled after its pressurized...
. When deflated, inflatable modules provide an 'easier to launch' compact form. When fully inflated, TransHab would expand to 8.2 metres in diameter (compare to the 4.4 metre diameter of the
Columbus ISS ModuleColumbus is a science laboratory that is part of the International Space Station and is the largest single contribution to the ISS made by the European Space Agency ....
).
History
The name of the project is a contraction of
Transit Habitat reflecting the original intention to design an interplanetary vehicle to transfer humans to Mars.
Considerable controversy arose during the TransHab development effort due to delays and increased costs of the
ISSThe International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
program. In 1999, the
National Space SocietyThe National Space Society is an international nonprofit 501, educational, and scientific organization specializing in space advocacy...
issued a policy statement recommending that NASA continue R&D of inflatable technologies while ceasing development of a TransHab ISS module. Finally in 2000, despite objections from The White House, House Resolution 1654 was signed into law banning
NASAThe National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
from conducting further research and development of TransHab. An option to lease an inflatable habitat module from private industry was included in the bill.
Since that time, the private company
Bigelow AerospaceBigelow Aerospace is a North Las Vegas, Nevada space technology startup company that is pioneering work on expandable space station modules. Bigelow Aerospace was founded by Robert Bigelow in 1998...
has purchased the rights to the patents developed by NASA and is pursuing a similar scheme for a private space station design. The company has launched the
Genesis I and
Genesis IIGenesis II is a 1973 American TV film created and produced by Gene Roddenberry and directed by John Llewellyn Moxey.It opens with the line, "My name is Dylan Hunt...
pathfinder spacecraft, with plans for additional experimental craft culminating in their
BA 330 production model and the
Bigelow Commercial Space StationThe Bigelow Next-Generation Commercial Space Station is a private orbital space complex currently under development by Bigelow Aerospace. The space station will be constructed of both Sundancer and BA 330 expandable spacecraft modules as well as a central docking node, propulsion, solar arrays,...
.
Technology
The TransHab design called for a hybrid structure that combines the packaging and mass efficiencies of an inflatable structure with the advantages of a load-bearing hard structure.
Multi-Layer Inflatable Shell
TransHab's inflatable shell consisted of multiple layers of
blanket insulationThermal insulation is the reduction of the effects of the various processes of heat transfer between objects in thermal contact or in range of radiative influence. Heat transfer is the transfer of thermal energy between objects of differing temperature...
, protection from
orbitalSpace debris, also known as orbital debris, space junk, and space waste, is the collection of objects in orbit around Earth that were created by humans but no longer serve any useful purpose. These objects consist of everything from spent rocket stages and defunct satellites to erosion, explosion...
and
meteoroidA meteoroid is a sand- to boulder-sized particle of debris in the Solar System. The visible path of a meteoroid that enters Earth's atmosphere is called a meteor, or colloquially a shooting star or falling star. If a meteoroid reaches the ground and survives impact, then it is called a meteorite...
debris, an optimized restraint layer and a redundant bladder with a protective layer.
TransHab’s foot-thick inflatable shell design had almost two dozen layers. The layers were fashioned to break up particles of space debris and tiny meteorites that might hit the shell with a speed seven times as fast as a bullet. The outer layers protect multiple inner bladders, made of a material that holds in the module’s air. The shell also provides insulation from temperatures in
spaceOuter space is the void that exists between celestial bodies, including the Earth. It is not completely empty, but consists of a hard vacuum containing a low density of particles: predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, and neutrinos....
that can range from plus 121 degrees Celsius (plus 250 degrees Fahrenheit) in the Sun to minus 128 degrees Celsius (minus 200 degrees Fahrenheit) in the shade.
The key to the debris protection in the design and prototype units was successive layers of Nextel, a material commonly used as insulation under the hoods of many cars, spaced between several-inches-thick layers of open cell foam, similar to foam used for chair cushions on Earth. The Nextel and foam layers cause a particle to shatter as it hits, losing more and more of its energy as it penetrates deeper.
Many layers deep in the shell was a layer of superstrong woven
KevlarKevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...
to hold the module’s shape. The air was held inside by three bladders of Combitherm, a material commonly used in the food-packing industry. The innermost layer, forming the inside wall of the module, was
NomexNomex is a registered trademark for flame resistant meta-aramid material developed in the early 1960s by DuPont and first marketed in 1967.- Properties:...
cloth, a
fireproof-Track List for Original 2002 Release:# "Fireproof" – 3:46# "Just 2 Get By" – 4:17# "Echelon" – 3:25# "Stay Up" – 3:40# "Behind Closed Doors" – 2:55# "Epidemic" – 3:14# "Hindsight" – 2:57# "Light at My Feet" – 3:28# "A Shame" – 3:17...
material that also protected the bladder from scuffs and scratches.
TransHab layout
TransHab was intended to be composed of four levels/floors.
Level 4
- The Pressurized Tunnel Area was intended to provide a passageway between TransHab and any vehicle to which it is attached. The original tunnel design had two standard International Space Station hatches and housed critical equipment required during module expansion, such as avionics and power equipment.
Level 3
- Level Three was to house an exercise area with a treadmill and stationary bicycle. The design also contained a complete health care system with all types of medical and emergency equipment and a type of "space bath" area provided for body cleansing. In addition, this level contained a soft stowage area identical to level one.
- Crew Health Care Area -- The design for the crew health care area incorporateed two ISS Crew Health Care System racks, a Full Body Cleansing Compartment, changing area, exercise equipment (treadmill and ergometer), a partitionable area for private medical exams and conferencing, as well as an Earth-viewing window. The Earth-viewing window was to have been 51 centimeters (20 inches) in diameter and was located near the exercise area. The window design had four panes totaling 10.2 centimeters (4 inches) thick and a hard frame around each window that attaches to all layers of the shell.
- Stowage -- Soft-sided cabinets was to have provided stowage for spare parts, supplies, clothing and other equipment. If built, TransHab would have doubled the stowage room available on the International Space Station.
Level 2
- Crew Quarters -- The crew quarters area design had six individual crew quarters, sized at 2.3 cubic meters (81 cubic feet) of volume per crew quarter, and a central passageway located within the second level central core structure and water tanks. Each compartment contains a sleeping bag/sleep restraint, an area for stowing personal items, and a computer entertainment center for recreation and personal work.
- Mechanical -- The mechanical room is external to the core structure and uses only half the floor space. It is acoustically and visually isolated. The other half of this area is a clerestory above the wardroom area. The mechanical room consists of an environmental control and life support system, power equipment and avionics equipment and provides return airflow from Level One and Level Three through openings.
Level 1
- The first level was to house a kitchen with a refrigerator-freezer, microwave oven, water dispenser, and food preparation equipment as well as a table that seats 12, enough to allow an entire Station resident crew and replacement crew to sit together for meetings or meals. There were to be three galley racks, a large wardroom table, an Earth-viewing window and a soft stowage array. The Earth-viewing window design was 51 centimeters (20 inches) in diameter and is located near the dining area. The window has four panes totaling 10.2 centimeters (4 inches) thick and a hard frame around each window that attaches to all layers of the shell.
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