ISS-TransHab attached to ISS during assembly operations

Partially dissected view through layers of the TransHab shell

Vertical cutaway showing all three levels.

CAD diagram of core structural components

TransHAB Shell Development Unit (SDU)

Level Three: Exercise Area and Stowage

Semi-transparent cutaway of Level Two core area

Isometric view of wardroom and galley areas of Level One

Two studies for woven pattern of TransHab shell's inner "scuff barrier"

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TransHab was first conceived in 1997, by a team of engineers and architects at the Johnson Space Center. In October the Space Human Factors group was asked to join the design team in developing the best  size and layout for the spacecraft.  Based in part on psychological, social, operational and anthropometric** lessons learned from earlier US and Russian missions, the team recommended a three-level internal layout and a shell radius of 7 feet [2.15m] greater than the core; crew quarters isolated at the center; mechanical systems grouped together in a separate “room” and exercise and hygiene situated on a different level from the public functions of kitchen, dining and conferencing.


Space Human Factors:

The ISS-TransHab was designed based on lessons learned from American and Russian experience in long-duration spaceflight, including:  Skylab**, Salyut ** and Space Station Mir**.  As space missions become longer, human performance is increasingly significant to the success of any extended mission.  TransHab’s generous volume—over 342 cubic meters—allows this vehicle for the first to offer the crew “rooms” for different activities without the need to stow and deploy equipment.  In other words, TransHab is planned for continuous, low-friction use by a diverse crew. 



TransHab is a wonder of applied engineering: cutting-edge materials technologies have been borrowed from various terrestrial applications and combined to create the first viable space inflatable structure.  Space inflatables have long been considered a valuable idea because of their high volume-to-mass ratio; due to the technologies used to insert payloads into orbit, it currently costs nearly US$10,000 to launch 600 grams of mass to LOE.  However, an inflatable alone does not have the stability to function well in a vacuum.  Cosmonaut Aleksei Leonov attempted to use an inflatable airlock from a Soyuz module in the late 1960s with unsatisfactory results. TransHab has broken both this barrier, and proven in ballistic, vacuum and radiation tests that this type of vehicle is viable for spaceflight. 



Because of the need to save weight, TransHab’s design is specifically intended for use in a microgravity environment; in other words, once it is unfolded, its internal structures are not capable of carrying weight.  Like the Apollo Lunar landing module, it would collapse if people tried to use it on Earth or Mars, though both are every bit as strong as they need to be to do the job in space or on the Moon.

This means that TransHab itself is best used only on orbit or in space travel to another destination in the Solar System.  However, the concept of TransHab—of designing an “endoskeletal” habitat—can easily be applied to surface applications like greenhouse or dwelling modules on the surface of the

Moon or Mars [see KJKennedy essay].  And, since the whole package is made to deploy itself with little or no human intervention, it is also ideal for use in other hazardous environments like Antarctica.



TransHab has been reviewed and approved by spaceflight experts who designed such vehicles as the X-15, Mercury, Gemini, Apollo and Space Shuttle.  Because of funding, further development of TransHab and other parts of the Mars DRM is still slow; but it is very likely that a TransHab type spacecraft will be built and deployed on orbit by the year 2010, and ready to support the first human mission to Mars as early as 2020.



Combining ancient methods like basketweaving with the most advanced technologies of our time,  TransHab profits in its conceptualization and design from the combined experience of three decades of American and Russian spaceflight.  As such, it is a fusion of innovative engineering with the entire history of human travel in space.  TransHab represents a major benchmark in typology, integrative design method and technology which will enable humans to take the next step in scientific exploration of our Solar System.

Constance M. Adams, RA, Architect / Space Architect



**denotes technical terms significant to space science which should be included in a glossary in this series

TransHab Project Team (1997-2000) includes: (bolded name is system lead)
Donna Fender, Project Manager
Horacio de la Fuente, Chief Engineer, Deputy Project Manager
George Parma, Deputy PM
Kriss Kennedy, RA/ Damon Wilson / Tim Lawrence / Geoff Degraff, Systems Engineering& Integration
Constance Adams, RA ,Vehicle Architecture and Integration
Constance Adams, RA / David Fitts / Janis Connolly / Kurt Bush / Webb Byford / Lee Webb, Crew Accommodations
Gregg Edeen / Jasen Raboin / Gerry Valle / Shalini Gupta / Gary Spexarth, Structures
Elizabeth Kluksdahl / Jose Christian, Power
Bill Dwyer / Bob Davis, Avionics (Command and Data Handling)
John Cornwell / Karen Myers / Jay Almlie / Tom Paul / Fred Smith, Environmental Control and Life Support Systems
Randy Rust, Safety
Mike Pedley / Rajib Dasgupta, Materials
Steve Rickman / Raul Blanco / Gautam Badhwar, Environments and Radiation
Bill Studak, Inflation
James Dunn, ISS Interface

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