Space stations

[veltyen]

Piper, I think you dropped something.

Ca= 0.011 * C(rpm)^2 * Cl

We want CA to equal 10 (approximately). C(rpm) we want to be one (for one rpm) which is nice because it disappears. Cl is the radius.

Cl= 10/0.011 =~ 900 metres.

Still, its a little over a mile across in diametre.

 

[parmasson]

Thanks math guys!

If I am right the displacement of this station is around 275 million tons excluding the hub if it is a torus. A radius of 900m, distance form torus to the center of the tube 241.5m. Volume = 2 * pi2 R * r2
Then again I have not been faced with real math for Mmmm . . .twelve-teen years.

Perfect! Just think of the possible disasters with all those people on board in that huge space. This is going to be better than I thought.

A station moving too fast as a malfunction could make for an inserting situation. Not only does your stuff weigh double what it did before but you keep having to make those Endurance checks to see if you vomit right in the middle of combat!

 

[Golan2072]

One good web page for space stations/habitats, extended/hydroponic life support, TL8 in-system development and belting in general: PERMANENT. Their opinions on "Planetary chauvenism" and several other ideas have even inspired the Matriarchate, one of the polities IMTU.

 

[BetterThanLife]

Now lets consider one other thing. The reason to spin a station is to produce artificial gravity. Remember this though.

What is the purpose of your station? In many cases imparting that much angular momentum means other functions won't work as well. Hard to aim a telescope or comms laser from a spinning object. it is also very difficult to dock with such a station.

Therefore once artifical gravity works, there is little incentive to spin a station.

If you are going t o spin it though, then a spindal arrangement, ala Babylon 5 works more effeciently than a wheel, or double wheel. (2001)

 

[Pickles]

I don't recall ever seeing any figures for volume or cost of artificial gravity in LBB2 or HG. Do any of the other systems have stats for artificial gravity? I know it's kind of ignoring the problem, but just going by CT rules there is no reason to use spin gravity.

Another point: imparting spin and mass to a station must also have cost and mass penalties. I wonder how these would compare against gravitics, and whether the additional mechanical complexity would be worth it.

 

[far-trader]

I think TNE FF&S1 was the first to break down cost, power, and volume for AG and Inertial Compensation in the life support section. Which was nice since you could build stuff without the fancy magic gravity stuff.

Spin gravity would I think be very low or negligiable in extra cost, mass and power, unless you will require it to be spun up and down regularly and quickly.

Of course as you say, for CT at least (inlcuding HG and T20) spin gravity is a non-issue. Magic gravity comes in at TL7(?) iirc (TL9 at the latest) so anything built from then on will do it that way. Even the 400ton labship with it's built in spin gravity option would be for micro-gravity only since the diameter is too small for comfortable full gravity.

 

[Piper]

Originally posted by veltyen:
Piper, I think you dropped something.

Ca= 0.011 * C(rpm)^2 * Cl

We want CA to equal 10 (approximately). C(rpm) we want to be one (for one rpm) which is nice because it disappears. Cl is the radius.

Cl= 10/0.011 =~ 900 metres.

Still, its a little over a mile across in diametre.

Yes, I did. Good catch.
I plead the lateness of the hour and a dull pencil.

 

[parmasson]

I have a few reasons for using spin instead of AG.
1. supposedly there would be an enormous energy savings as you did not have to provide a huge facility with AG.
2. Plot related. I don't want any big starships available to them.
3. The power is going to go out but I don't want to mess with 0g stuff.
4. If the controls go wonky there is the possibility of the fast spin and the nausea effect, a cool non-lethal hazard.

5. Because I think spinning stations are cool and I want one.

 

[Pickles]

Originally posted by Parmasson:
5. Because I think spinning stations are cool and I want one.

Best reason ever!

 

[Fritz_Brown]

Besides the nausea issues, there are structural issues to turning the thing too fast.

Docking can be done by matching speed inside the ring (not outside, as you would need a lot of strength to keep the thing connected - think slingshot), or by connecting to the spindle/center. (Inside, of course, people can run into things...

) And, anything that needs to be "stationary" can be placed on the center/spindle.

Cool ideas.

 

[parmasson]

Ah, a 1g landing pad on the "inside" of the ring so down is the bottom of the ship.
<scribble, scribble>

One of the tasks will be that the hub contains most of the power and stuff they need to get to. For various reason the "spokes" will not be available to them. They will have to climb up the outside of the spokes to get to the hub in nothing but standard TL-9 vacc suits. Of course as you approach the center the force lessens as s does the chance you will be thrown off into space but there is always that chance!

It could also be a good way of launching escape pods or your 20 ton launches if there were a few docking bays on the outside of the ring. Open the door and ZING out they go!

 

[Fritz_Brown]

Originally posted by Parmasson:
It could also be a good way of launching escape pods or your 20 ton launches if there were a few docking bays on the outside of the ring. Open the door and ZING out they go!

Good point! Of course, if you had the docking hatch at, say, a 30* angle from the radius, you would get a wierd floor, but when you let go, you could just fling away without hitting anything. (And, of course, the problem with matching speed on the inside of the wheel is that you have to match angular velocity, as well.)

 

[Piper]

Originally posted by Parmasson:
... A station moving too fast as a malfunction could make for an inserting situation. Not only does your stuff weigh double what it did before but you keep having to make those Endurance checks to see if you vomit right in the middle of combat!

What if only some of the thrusters misfired? It might throw the center of rotation off so that the gravity varies as the station rotates. It also adds the possibility of damaging the station due to stress on the ring; deformed or buckled hallways, breaches and so on.

 

[Fritz_Brown]

If your rotation thrusters weren't aligned with the center of the ring, you might get some interesting effects. Nobody here would build one that way, but....

 

[Rossoneill]

I think Marc Millers T4 had ag and gravity comp tables .
I might be wrong on the above but i know FF&S does

 

[parmasson]

Good ideas all. When those stress cracks form and a couple of sections suffer explosive decompression. Creak, creak, KABoo… <silence>

Fun.
No wonder so many characters die in generation. A minor asteroid strike followed by a routine thruster correction then oops. Gosh so many ways to die! I mean . . .um . . .well. adventure.

Didn't Mark Twain say that adventure was something bad happening to someone else far way?

FFS is the next book I need to order.
The Wannabe's gearhead reading list as I know it
Must study . . .
LBB 2 - got it
High Guard - got it
Fire Fusion and Steel - need it
Book 8 - Robots - got it
What else?

 

[Pickles]

Originally posted by Parmasson:
The Wannabe's gearhead reading list as I know it
Must study . . .
LBB 2 - got it
High Guard - got it
Fire Fusion and Steel - need it
Book 8 - Robots - got it
What else?

Striker!

 

[Uncle Bob]

Striker has vehicle and heavy weapon design rules for CT. I think it is more useful for a CT ref than FF&S.

FF&S has some interesting information in it, but I never thought the extra detail made better designs than High Guard or Striker, just more work. In fact, trying to recreate RW TL 5-7 designs is very frustrating in cases where Striker is pretty close.

Also our group in college replaced Book 1 combat with Striker combat. Less book-keeping, faster moving, more visceral and realistic.

 

[Whipsnade]

Parmasson,

While you're at it, check out C.J. Cherryh's novels, especially those set in her Merchanter universe (Down Below Station etc.) and the Chanur series.

Besides her always excellent plots and characterizations, she features quite a number of very large - okay HUGE - spinning space stations. In her books, ships dock along the ring in order to enjoy 'gravity' while docked.

She also has any number of other ideas a savy GM can 'port into Traveller; mainday and alterday crews aboard ships, ships that produce gravity by both spin and thrust, containerized freight, etc. One book; Finity's End IIRC, has one of the best descriptions of rapid speculative trading I've ever read.


Have fun,
Bill

 

[parmasson]

My Traveller adventures are coming along nicely thanks to everybody here. Just signed two more men aboard the Imperial Patrol Curser Apocalypse on its continuing mission to try and stay alive. I am hesitant to recommend the forum for fear that it will damage my reputation!