RE: starship-design: Planetary Landing

[Timothy van der Linden <Shealiak@XS4ALL.nl>]

Hi Lee,

>A starship only has to be designed to accommodate acceleration stresses in
>one direction only. Any stresses that may be placed upon the structure of
>the ship in other directions than straight "ahead" are miniscule. A vehicle
>reentering the atmosphere however, is subjected to transverse stresses on
>several planes at once and these stresses can easily "peak" at hundreds of
>g's.

Would the ship be subjected to transverse stresses even if the speed
relative to the atmosphere would be virtually zero? I'm imagining a radial
path towards the surface of the planet (just like these single stage
X-crafts can land), so I'd guess only wind or turbulence creates stesses in
other directions. 

>The added weight of structural elements to resist these forces would double
>the weight of the ship easily. In addition, if it must be designed to
>support itself while on the ground, you can add even more mass. (This is one
>of the reasons why early science fiction authors liked to land their ships
>in water, it helped to spread out the structural load.)

The same frame that distributes the forces of the 1g boosters to the rest
of the starship should also be able to distribute the forces from the
landing gear.

>So far, based on known technology, the ship will probably mass between
>400,000 and 4,000,000 million metric tons. I can't see trying to land
>something that size ANYWHERE.

Oh, don't misunderstand me, I see no reason to land a starship. I'm
convinced that when we can make a starship, we also have no problem making
a few shuttles that could repeatedly do trips to the surface of an Eartlike
planet.

Timothy

Please sent replies to the "starship-design@lists.uoregon.edu" addresse ONLY.