Partial Torus Station

Does anyone have any comments on the viability of a spacecraft such as the one I posted in the link below?

(I couldn't figure out how to post a photo so I posted it to my Facebook feed and linked it below.)

https://www.facebook.com/photo.php?f...1288363&type=3

I'm sure more learned people have considered such an intermediate approach to provide artificial gravity while conserving construction costs but it's hard to find information about current research on it.

If a successor to the ISS has been in the planning, why can't it be a partial torus?

David Hoag
Space Enthusiast

On Dec/26/2016 at 8:43 AM, David Hoag wrote :

Does anyone have any comments on the viability of a spacecraft such as the one I posted in the link below?

(I couldn't figure out how to post a photo so I posted it to my Facebook feed and linked it below.)

https://www.facebook.com/photo.php?f...1288363&type=3

I'm sure more learned people have considered such an intermediate approach to provide artificial gravity while conserving construction costs but it's hard to find information about current research on it.

If a successor to the ISS has been in the planning, why can't it be a partial torus?

David Hoag
Space Enthusiast


A full torus is a stronger shape than a partial torus. You would have
large stresses at the T junction where the axis meets the circle arc. If
you want to reduce costs by having less than a full torus, why not just
have a habitat at the end of a long spinning cable. At the other end of
the cable you can put a second habitat, or just dead weight (spent fuel
tanks could be used for the dead weight). The habitat can have any
shape, so you choose the shape which best suits your needs. That shape
is unlikely to be a partial torus.


Alain Fournier

Mr. Fournier,

A complete torus station is a bit far-fetched at this stage I suppose due
to construction costs (R&D, a multitude of launches, diameter of torus tub
e sections), and having a single habitat connected with a cable (or series
of cables for redundancy) with a counterweight would be cheaper than two co
nnected with a traversable tunnel and hub, I agree. I wanted to suggest a
scalable/modular design that could be augmented proportionately with more a
nd more segments until it became a full torus.
As far as I know (I'm not a mechanical engineer by any means), the curren
t hull structure of the ISS is considerably stronger than it needs to be so
we have somewhat suitable materials already. The stresses you mentioned,
of course, were stresses experienced by spinning. While a tube connecting
two habitats with a large enough diameter to serve as a passageway would be
more expensive, the hull of said tube could contain several cables as well
as life-support systems, storage and gradients of micro-gravity to serve a
s research for partial-gravity experiments. I would advocate a second habi
tat to act as counterweight for safety reasons as well as a more financiall
y justifiable payload. Spent fuel tanks would be impractical because fuel
tanks are rarely empty and even if they are, it is temporary thus necessita
ting constant rearranging. A second habitat of identical mass would be dif
ficult to engineer (say four astronauts piled into one habitat and nobody w
as in the opposite one - would that throw out the orbit?) but cantilevers o
r gyroscopic controls may hold an answer.
The rudimentary sketch I drew was tube-shaped to anticipate the addition
of more modules eventually making a stronger, full torus. Politically and
financially, the initial construction would have to be somewhat habitable t
o justify the years (perhaps decades) of planning and likely billions and b
illions of dollars. Without proper artificial gravity designs to test near
Earth, interplanetary travel carries too great a cost mentally/physiologic
ally to participants in Mars missions.