Space Ships

[bednobs]

could you make them any shape - after all aerodynamics don't matter in space do they?

[woofgang]

well but aerodynamics matter when you are getting the spaceship into space

[Prudie]

I'd have thought any shape too, the Enterprise didn't appear to be very streamlined, neither did the thing that picked ET up. Are we not making assumptions on how things move in air rather than space?

[ChuckFickens]

Yep... it makes bugger all difference what shape a structure in space is.

[jno]

depends if you want them ever to land, I suppose. If they're just going to sit up there like the space station they can probably be the shape of the British Museum. But if you actually want to go somewhere and get out when you've arrived, you might need to consider being aerodynamic.

[excelsior-1]

the simple answer, bednobs, is yes

no aerodynamics in space so, as in star trek - any shape will do....there are even ships that are cube shaped (the borg)

but they could not be used in a planetary atmosphere effectively

[beegeebee]

Just wondered where you go, if you did have a space ship? When Scientists say x galaxy is y light years from us, how can they know if it actually still there? Has always intrigued me

[jim360]

The dynamics of stars and galaxies are such that you can have a reasonable estimate of their lifetime. Some, undoubtedly, are not -- the ones in the very distant past have certainly changed beyond all recognition "now" -- but most of the ones nearest us are still around, to some extent.

However, "Now" is something that has little meaning for the Universe, because of Relativity effects.

[jake-the-peg]

Aerodynamics don't matter but stress and inertia does

Imagine a large spaceship with two bug arms sticking out the side and a big engine between them.

If the engine kicks in suddenly and powerfully the stresses at the joints of the arms would cause failures.

That's not a problem if you have a small steady constant acceleration from something like an ion drive but it does if you have a big powerful engine.

So I guess the answer is 'it depends'

[jim360]

Not really, inertia would be a response to the force being applied from the rocket itself. I don't think that would change just because there is no gravity. And, anyway, there is gravity, it's just very weak.

[naomi24]

I remember reading somewhere that the ideal shape for an inter-stellar space-going vehicle is a ball. Can't remember why, nor where I read it... but it's too late in the day to investigate. Perhaps someone else can throw some light on it.

[beso]

naomi24 //I remember reading somewhere that the ideal shape for an inter-stellar space-going vehicle is a ball. Can't remember why//

Maximum contained volume for the construction materials used.

[bhg481]

I am intrigued by people using spaceships from Startreck as examples - it was fiction.
The moon-landing craft (Eagle) did exist and was hardly aerodynamic because it was only intended for use in vacuum conditions.

[naomi24]

Beso, yes, something like that. I remember that gravity was involved in the theory.

[jake-the-peg]

No Rob - inertia is still there in the absence of gravity

Interlia is the tendency of a body to resist acceleration or deceleration - Newton's first law F=ma

Try this - Imagine three pencils in space connected by string - give the middle one a push - what happens?

The middle one goes off and pulls the others behind

Now imagine stiffer and stiffer connections - the forces are still there it's just they're resisted more effectively but that translates to stress in the material of the arms

[nescio]

Jake,
"Newton's first law F=ma " ?
His first law is indeed that of inertia.
F=ma is his second.

[Teddio]

Any spaceship, even in the vacuum of space and free from gravitational field, will have momentum. Force is the rate of change in momentum. Therefore if the space ship accelerates or decelerates there will be a force imposed on the structure.
The shape of the structure is therefore important.
The International Space Station is effectively in free-fall around the Earth but even it needs periodic re-boosts from a rocket to increase its orbital height.

[ToraToraTora]

yes jake that's why the Enterprise has intertial dampers! from impulse to warp would atomise everything!