Page 3 of 4

Posted: Thu Aug 16, 2007 6:31 pm
by Arexack_Heretic
And Eon by Greg Bear.
Also a genship returning home...only it's inhabitants have left their confinement by a transdimensional technology that caused the rock to return home before it is launched, just in time to trigger WW3.

ps I find the title a bit misleading...there is no chism.
A chism indicates a widespread herecy, including some of the clergy joining both sides.
A title like 'Dogma Rewarded' or something 'Vessel of Truth' would be more fitting.

Still a fun shortstory. :)

Posted: Fri Aug 17, 2007 3:55 am
by Cmdr. Maegil
Arexack_Heretic wrote:
I find the title a bit misleading...there is no chism.
A chism indicates a widespread herecy, including some of the clergy joining both sides.
A title like 'Dogma Rewarded' or something 'Vessel of Truth' would be more fitting.
Thus Spake the Heretic! :wink:

Posted: Fri Aug 17, 2007 6:42 am
by drew
Perhaps it should have been 'Schism?'

Cheers,

Drew.

Posted: Sun Sep 09, 2007 8:35 pm
by Draco_Caeles
For those who might be interested, I've posted an animation of my Generation Ship up on YouTube.

You can find it here: http://www.youtube.com/watch?v=aA-PNr6dQg8. I would value any comments and criticisms you might have. :)

Posted: Mon Sep 10, 2007 6:44 am
by TGHC
Excellent, the sheer size of it! even more than I expected it to be.

Well done that man.

Posted: Mon Sep 10, 2007 10:59 am
by Commander McLane
Draco_Caeles wrote:
For those who might be interested, I've posted an animation of my Generation Ship up on YouTube.

You can find it here: http://www.youtube.com/watch?v=aA-PNr6dQg8. I would value any comments and criticisms you might have. :)
Looks great, awesome!

However as to the model itself I have some questions, especially as far as these huge parabola antennas are concerned. (1) What are they for? They are pointed roughly forward, so they are not meant as a means of communication with the ship's origin. This would require them to be pointed backward. Shall they scan the ship's destination? Permanently? Shall they find a destination (but I would guess the ship is aimed a a specific star right from the beginning)? Shall they just scan the sorrounding space, as an early-collision-warning? It's just so many of them. (2) Does their sheer size make them a likely design-feature for a Generation Ship? The ship is designed to travel literally hundreds of years. How many collisions with mikro- and makro-objects will it have during its life-span? Must be millions. NASA-satellites have been severely damaged by space-dust. So would after hundreds of years these huge antennas have survived unharmed? Would they simply still be there anymore? What I would do if I had to design a Generation Ship would be to give it the geometrically most simple and strong hull possible (therefore I agree entirely with the basic ton-design) and attach as few things as possible sideways to that hull, ideally nothing at all.

A last remark concerns the size of the ships exhaust-plume. In the original genships.oxp it's very short. Huge (as the engine), but short. I like that. Therefore the plume in the animation seems very long to me. Obviously (if we're not in the Ooniverse) the ship is accelerating heavily at the time of the encounter. For maintaining its speed in the real universe it would need no engine at all. (Of course there is one possible design-scheme for a generation ship that would require it to accelerate for the first half of its journey, then turn around 180 degrees and decelerate for the rest of the journey by keeping its engines firing, thus maintaining a 1-g-gravity-environment inside the ship. But I guess in your ship the rotating cylinders are taking care of gravity, so no reason to accelerate all the time. (EDIT: No, on re-viewing the animation I see the cylinders don't rotate anymore. Why?)) Anyway, my very personal-taste point here is just that I like the short exhaust-plume more.

For the rest of it (I like the huge fuel-tanks! definitively a good addition to the first design!) and the animation itself, just again: awesome! :D

Posted: Mon Sep 10, 2007 9:22 pm
by Draco_Caeles
Commander McLane wrote:
Looks great, awesome!
Thank you! :D
However as to the model itself I have some questions, especially as far as these huge parabola antennas are concerned. (1) What are they for? They are pointed roughly forward, so they are not meant as a means of communication with the ship's origin. This would require them to be pointed backward. Shall they scan the ship's destination? Permanently? Shall they find a destination (but I would guess the ship is aimed a a specific star right from the beginning)? Shall they just scan the sorrounding space, as an early-collision-warning? It's just so many of them. (2) Does their sheer size make them a likely design-feature for a Generation Ship? The ship is designed to travel literally hundreds of years... <snip>
The answer to both of those questions, really, is this: the large dishes are scoops to gather whatever gases, bits of debris, pieces of smallish space-junk, etc., the ship happens to pass through. The stuff is 'processed' in the large ovoids at the bottom and added to the fuel supply, to be burned immediately or stored for future use.

My thoughts were that while the ship may coast for much of its time, it would still need fuel: to power the onboard systems, make course corrections, and so on, and I really didn't think it even slightly realistic that it would be able to carry, and move, several hundred/thousand years' worth of fuel. The answer: provide a method to replenish supply.

I agree with your point about collisions: had I had the time, several of the scoops would indeed have been damaged. I was also thinking about having had an asteroid impact on one of the cylinders, but this just wasn't feasible. Time ran out, and my computer (a 4.2GHz AMD with 2GB RAM) was already struggling with the 3.5M polys, so that just wasn't going to happen.
A last remark concerns the size of the ships exhaust-plume. In the original genships.oxp it's very short. Huge (as the engine), but short. I like that. Therefore the plume in the animation seems very long to me. Obviously (if we're not in the Ooniverse) the ship is accelerating heavily at the time of the encounter. For maintaining its speed in the real universe it would need no engine at all. (Of course there is one possible design-scheme for a generation ship that would require it to accelerate for the first half of its journey, then turn around 180 degrees and decelerate for the rest of the journey by keeping its engines firing, thus maintaining a 1-g-gravity-environment inside the ship. But I guess in your ship the rotating cylinders are taking care of gravity, so no reason to accelerate all the time. (EDIT: No, on re-viewing the animation I see the cylinders don't rotate anymore. Why?)) Anyway, my very personal-taste point here is just that I like the short exhaust-plume more.
In the OXP the plumes were supposed to be bigger, but for some reason I couldn't make them long as well as wide: hence the smallish flickerflame.

I appreciate what you say about the size of the plume. However, in the clip the genship is supposed to be making a course correction to avoid a gravity well, hence the attitude thrusters also firing. And given the sheer raw inertia of the damned thing, it's not such a big plume: Galactica is to scale. From central axis to the yellow points of the cylinder is radius 3.2 km; to the edge of the gantry, about 5km. She's 70km long. That's a lot of mass to move.

And yes, the cylinder's don't move. This is because I'd turned the ship to get the right perspective relative to star and planet-moon, for the right look, and by the time I'd got it there it was in a very funny position. 3DS Max didn't seem to want to let me rotate it correctly, so frankly I gave up. Also, given the scale I've built her to, the rotation would be of the order of a fraction of one rpm: the rotation in the OXP is exaggerated.
For the rest of it (I like the huge fuel-tanks! definitively a good addition to the first design!) and the animation itself, just again: awesome! :D
*smiles and bows* Thank you very much :)

Posted: Tue Sep 11, 2007 8:05 am
by Commander McLane
Draco_Caeles wrote:
Commander McLane wrote:
However as to the model itself I have some questions, especially as far as these huge parabola antennas are concerned. (1) What are they for? They are pointed roughly forward, so they are not meant as a means of communication with the ship's origin. This would require them to be pointed backward. Shall they scan the ship's destination? Permanently? Shall they find a destination (but I would guess the ship is aimed a a specific star right from the beginning)? Shall they just scan the sorrounding space, as an early-collision-warning? It's just so many of them. (2) Does their sheer size make them a likely design-feature for a Generation Ship? The ship is designed to travel literally hundreds of years... <snip>
The answer to both of those questions, really, is this: the large dishes are scoops to gather whatever gases, bits of debris, pieces of smallish space-junk, etc., the ship happens to pass through. The stuff is 'processed' in the large ovoids at the bottom and added to the fuel supply, to be burned immediately or stored for future use.

My thoughts were that while the ship may coast for much of its time, it would still need fuel: to power the onboard systems, make course corrections, and so on, and I really didn't think it even slightly realistic that it would be able to carry, and move, several hundred/thousand years' worth of fuel. The answer: provide a method to replenish supply.

I agree with your point about collisions: had I had the time, several of the scoops would indeed have been damaged. I was also thinking about having had an asteroid impact on one of the cylinders, but this just wasn't feasible. Time ran out, and my computer (a 4.2GHz AMD with 2GB RAM) was already struggling with the 3.5M polys, so that just wasn't going to happen.
Ah! :idea: It just never appeared to me that they could be something else than antennas. But of course, some kind of collectors make perfect sense. And of course they have to cover an area as large as possible. So, thanks for the explanation!

Posted: Tue Sep 11, 2007 3:19 pm
by Arexack_Heretic
Nice clip.
There could be a bit more action. or audio chatter anouncing what's going on.

Is it me or did I spot a tiny USS enterprise trailing behind the juggernaut at the end of it?
't Would make sense to depoy a few outrider scouts to triangulate the maneuvre and make sure no parts break off.

The dish antenae are a bit huge and there are a lot of them.
redundency is a good design feature, but then you generally just deploy only a single or maybe a double backup, keeping the rest stowed away for parts.
With so many deployed, I suspect this hulk has been taken over by radio pirates, broadcasting their malicious radiowaves of derrision to the universe. ;)

As for the not-rotating.
teknobabbling, it does make a lot of sense to stop the axial rotation when changing course, inertia can be a bitch.

Posted: Tue Sep 11, 2007 6:01 pm
by drew
Love it! Nice to see it in situ as it were.

I wondered whether or not a 'space drive' (ie. inertialess drive) might be more appropriate for a generation ship, but that's perhaps too advanced for a ship that ought to have been launched in the 2300's.

I think the scoops would actually work too. Earlier we estimated the speed of the gen ships as somewhere around 400,000 kms-1. At that speed, you'd probably be picking up measureable amounts of hydrogen with a scoop of that size.

I hadn't realised the scale was so large... 70km is enormous. Was 'Rama' that big? I can't remember. I wonder how you manufacture something like that!

Nice work though! Really excellent.

Cheers,

Drew.

Posted: Tue Sep 11, 2007 6:04 pm
by Captain Hesperus
drew wrote:
I hadn't realised the scale was so large... 70km is enormous. Was 'Rama' that big? I can't remember. I wonder how you manufacture something like that!
With lots and lots and lots of smaller bits.....:D

Captain Hesperus

Posted: Tue Sep 11, 2007 7:46 pm
by Draco_Caeles
Captain Hesperus wrote:
drew wrote:
I hadn't realised the scale was so large... 70km is enormous. Was 'Rama' that big? I can't remember. I wonder how you manufacture something like that!
With lots and lots and lots of smaller bits.....:D
*grins* Much as the model was built :) One section of cylinder-and-gantry was constructed and then copied... then the engineering section, and finally the head. All in all, the head changed the least.

And no, Rama wasn't that big. :)

Posted: Tue Sep 11, 2007 10:30 pm
by JensAyton
drew wrote:
I wonder how you manufacture something like that!
Take some asteroids. Apply some big lasers powered by a small fission reactor. Maybe some small nukes to help carving out the initial shape. A more advanced version of the UESC Marathon, made out of the moon Deimos (which is a mere 15 km long).

Posted: Wed Sep 12, 2007 10:26 pm
by Captain Hesperus
Draco_Caeles wrote:
and finally the head. All in all, the head changed the least.
They built 'the head' last!!!! :shock:
There must have been thousands of desperate workmen up til that point.
Or lots of accidents and laundry loads.......

Captain Hesperus

Posted: Thu Sep 13, 2007 1:27 pm
by Draco_Caeles
Captain Hesperus wrote:
Draco_Caeles wrote:
and finally the head. All in all, the head changed the least.
They built 'the head' last!!!! :shock:
There must have been thousands of desperate workmen up til that point.
Or lots of accidents and laundry loads.......
*grins* SOP for starship construction. If you look at the blueprints for the Enterprise, there's only one head...

... now you know why there are so many transporter rooms... it's easier than plumbing :D