Dynamics of system defense and other thoughts

[far-trader]

Originally posted by Hal:
So that I don't "influence" the discussion with my own biases, I would like for someone to create the following and submit it for discussion...

I'll have to get back to you on that, and further contributions, and probably not soon

Originally posted by Hal:

As for forming a secondary threat assessment committe - I propose we nominate that man to become a politician, BOY does he think like one

Hmm, is that an insult?

Vote me for Overlord, you won't regret it...

... at least not for very long

 

[Andrew Boulton]

You shouldn't really be using contact/proximity warheads for space mines, you should be using det-lasers.

 

[veltyen]

The problem with mines that are just as effective as missiles, enough armor and missiles just bounce off. Send a heavy armored ship through the refueling path a couple of times. Something like a carried SDB would be ok, if you didn't have a specialist "Heavy armored mine clearance refueling ship" available. Suddenly you can scoop there for a while. To counter this you could make the mines bigger/smarter/longer range, but that ups the price again. Considering the pure area involved, I think the closest you can have to mining a gas giant is hanging a bunch of buffered planetoid monitors in orbit.

Economics. This is for my own amusement, I use a non-canon method for GDP's. GDP of a pop 9 rich planet at TL7 is about 60 trillion (10^12) credits. TL's change this to 120 TCr at TL9, 240 TCr at TL11 and 500 TCr at TL13, so a feild somewhere between 50 and 500 TCr. Military budget of 2% of GDP is 1->10TCr. Yearly capital purchase budget for military purposes a figure of 100 GCr per year (1 to 10% of military budget) is not unreasonable.

Depending on the repurchase period thats between 2 and 4 Trillion credits for ships, installations, ground combatants and so on.

So, rounding down yet again, a Trillion credits is in the right ballpark for gear.

What a trillion Credits can buy:

100 Deep meson installations (rounded up to 10GCr from the figure given by Randy)
50,000 light space fighters
5,000 buffered asteroid listening posts (200 dTon)
200 Seydlitz Monitors (TL13, 5000 dTon, meson spinal)
75,000 Intrepid MBT (Grav)

... or more probably a combination of the above.

10 ground installations planetside (each approximately 10 GCr).
At low tech levels 10 GCr delivers an awful lot of missile silos in a dispersed formation. At high tech levels it allows a deep meson facility with a decent weapon. You don't want to ever use these, as it means the invading force is in weapons range of your populous.
5000 MBT(and other assorted ground vehicles)
If it is a ground assault then it might be an idea to register strong disapproval. Of limited use against an invading fleet, depending on its goal.
200 listening posts
Asteroids if you can get them in system. Otherwise the slightly more expensive and flimsier non-asteroid version would need to be used. 10 or so around each of the gas giants and factory platform, half scattered semi-randomly across the system, the rest attempting a sensors englobement of the main world. These are armed, but are more early warning systems then combatants. These are augmented by many automated repeaters and tripwires for each post.
Orbital defence platforms (2x 100k or more dTon)
Limited mobility, armoured, heavy reinforced planetoids. The number available would have more to do with the time since last invasion. Limited by what rocks are available in system, and the TL needed to go get them. These sit in an outer orbit around the mainworld, and are supplied and crewed from the homeworld. These are also one of the homes of the fighter fleet.
3,000 fighters
Mostly light fighters in the 10-20 dTon range, the rest are strike fighters (missile gunboats at low TL, fusion gunboats at higher TL). The majority are based as part of the main worlds COAC groundside, the rest based at the industrial platfrom and at the orbital defence platforms. Cargo runs between the mainworld and the industrial site will be escorted from this pool.
100 SDB
At low tech levels these are clunky missile boats. At higher TL these are heavily armoured fusion gunboats. These do the system patrol as small groups(2-5) and do escort duties on the fuel run and factory run in somewhat larger numbers.
20 Heavy Monitors (5k dTon)
The meat of the interception force. At higher TL these are something like the seyditz. At lower TL's the design spec stays the same (fast, well armored), but the primary attack reverts to being a missile system. These are formed into 4 groups, one at the industrial platform, one potentially on fuel escort duties, the remaining two near the homeworld. These are response units, and from the previous thread that engendered this one, the ships likely stolen by the imperium regularily.


Total
100k dTon Monitors
50k dTon SDBs
75k dTon Fighters
10x? dTon Ground installations
200k dTon+ orbital defence platforms
x dTon Maintenance vessels (not counted)

It would be expected that an invasion fleet would trip an alarm somewhere, and hopefully this would launch a wave of defences, starting with handfuls of SDB's that strike and the run away. This would lead to one of the monitor groups coming to investigate (the other three stay on station). Finally this leads to waves of fighters and planetary defences if the preceeding hasn't driven of the attack.

If the invasion fleet goes to a gas giant that is not on the immediate refueling path, then the listening posts stay quiet and do not engage.

 

[flykiller]

Whoa whoa whoa there everybody. Who says you need 1 mine per 1000km square? I mean where are you getting that as a reasonable figure Randy? Certainly given your numbers mines are useless. The real world tells us other wise in many applications.

well in the real world we don't try to mine a billion square miles.

it's a ruleset issue. how far can a mine sensor suite see in a gas giant atmosphere? how fast can a missile go in a gas giant atmosphere? how much time will defense systems have to respond? how damaging is this mine missile? etc.

recall that in "normal" space combat missiles are supported by a ship's computer and sensor suite which have a direct effect on the missiles' effectiveness. does a mine have similar support? if so, how much, and how much does it cost? if not but the mines are still just as effective then why doesn't everyone carry mines instead of missile bays? etc.

off-hand I don't see how any mine ruleset that follows existing traveller rulesets could allow the affordable mining of a gas giant.

 

[RandyT0001]

I assumed the cost per mine would equal the cost of a missile and generally have the same combat capabilities so that we might have some basis for incorporating them into combat using HighGuard combat system. I gave these 'mines' exceptional capability in the fact that they keep station despite the gas giant's winds (top speed on Jupiter about 170m/sec or about 380 miles/hour) and gravity. (To me the idea of laying mines in a gas giant atmosphere is like me throwing up leaves in a hurricane and hoping they float and stay in position.) To realistically compensate for this our mines should be much larger and much more expensive but we have 'special' mines. On to the next point.

As I said before let's assume that mines operate in a manner similar to missiles in the HighGuard combat system, it's the closest thing. So one of the 6424 mines detects an incoming ship, let's say a small Fer-de-lance escort, and begins it's attack on the ship. A factor one missile (there's only one missile) needs a base of six to hit. The ship's computer model 9 adds +9 to that (the missile has no computer), the ship's agility is 6 so add another +6, the target size code is K so add another +1, and the missile is operating at short range adding another +1 to hit, so you would have to roll 23+ to hit (on 2d6). No chance! Even if you had a missile attack factor of 9 because of the ship's computer and agility you still have no chance to hit (17+ on 2d6).

The use of mines that are based on the missile combat in HighGuard are only going to be effective against ships with small computers and low agility. If your mines are effective against the 'raiding' ships due to low computer model and low agility then, IMO, such 'raiders' aren't going to be much of a threat to your system in the first place. 200 Fer-de-lance DE's might disrupt your tanker convoys and destroy your 'remote' industrail complex but probably couldn't do much damage to the mainworld. If the mainworld has deep meson sites, even a few hundred built at low tech levels, I doubt that such 'raiders' would ever come within combat ranges of the mainworld.

So once again I will say that mines are ineffective and wasteful of funds.

IMO

 

[mike wightman]

I like the meson spheres idea.

I don't think the industrial stations can be defended though. All an attacker has to do is launch a massive kinetic missile strike from a long way out - attacking ships accelerate to high velocity a week away from the target, release a swarm of superdense rods aimed at the station :toast

Jump to three light weeks from the target system, accelerate at 6G for two weeks, launch strike, jump away to refuel. For added effect, launch from different directions...

All fixed orbit infrastructure could be wiped in this way.

 

[Andrew Boulton]

I don't think the GGs atmosphere is the best place to put the mines. In orbit is better. The big warheads are pretty nasty and have a decent range, but are almost impossible to detect.

Kinetic kill "shotgun" missiles are the thing to use in the atmosphere. Hypersonic metal slugs will make an awful mess of your scoops.

 

[RandyT0001]

Let's go over some of the points.

Refueling points - three gas worlds
The idea of defending the three gas giants with the intent to prevent refueling by the 'raiding' force is absurd and insane. There is no practical way to prevent gas giant refueling. Because of the size of gas giants and their number in system the number of ships required is prohibitively high. The use of a smaller number of ships, a squadron for example, with the intent to deter or disrupt refueling operations by a raiding fleet is wasteful of resources that should be used defending more strategically important potential targets. If the board continues to insist that all three gas giants be defended then they will be responsible for the disaster when the system defenses are spread too thin to offer adaquete protection for the mainworld. Though it might end my career I would question the compentence of the military strategic review board and ask: are they experienced line officers or amatuer, armchair adolescent strategists whose only experience is by playing paper map and cardboard counter wargames?

The gas giants should not be defended.

Refueling fleet
The refueling fleet brings fuel from the gas giant(s) to the mainworld. This is done for ecological and strategic reasons. The mainworld government does not want wilderness refueling to occur from the surface in order to prevent potential ecological damage. This ban on wilderness (free) refueling has the added benefit that the H2 resource that is present could be used as a strategic reserve in the event that the refueling fleet is disrupted and the gas giant resources are interrupted. Therefore the refueling fleet is used to resupply the fuel used by the planet for power generation and refuel both local and interstellar ships in the system.

I would set up this operation to operate on a weekly basis and that the amount required is, let's say, equal to X. So we build a fleet that can transport 1.5X. Each ship is jump capable and uses jump to travel to the gas giants (regardless of actual distance). By doing this we minimize the exposure of the refueling fleet to interception. At a minimum I would build twenty-one ships of which only ten or eleven are necessary to conduct the operation (The others are held in reserve, see below). That is seven per gas giant and a ship makes a jump every other day. There are five target destinations at each gas giant: one above, one below, one to each side and one 'in front' of the gas giant.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;"> *
*(*)*
*</pre>[/QUOTE]By using jump we minimize exposure one would find if we used maneuver drives to travel to the gas gaints. The ships are only at risks once they emerge and then only for the (relatively) brief skimming time. By random selection of a target jump-in point we make it more difficult for the 'raiders' to intercept. By having ships go to each gas giant the appearance of 'raiders' at one gas giant means their chance of causing a serious refueling disruption is lower. By jumping every other day once the appearance of 'raiders' is detected most of the refueling fleet can be redirected to uncontested gas giants or the operation stopped, saving as many ships as possible. Once the raid is stopped the refueling fleet can resume normal operations quickly by using ships from the reserve.

As always IMO and YMMV.
More to come.

 

[flykiller]

... are they experienced line officers or amatuer, armchair adolescent strategists whose only experience is by playing paper map and cardboard counter wargames?

good gracious. (raises hand) you'll have to put me down as an amateur, armchair strategist. adolescent, I wish. and I'm sure that that description fits everyone else here too, I doubt anyone here has line officer experience in these matters. c'mon man, be cool.

 

[RandyT0001]

Flykiller, it was meant as something of a tongue in cheek joke. My first paper map/cardbaord counter wargame was SPI's Kursk so I'm just as guilty as, like you say, everybody here. I'll add a smiley to it.

Who do you think Maxius Panennek is based on? He's an absurd exaggeration of myself in those days (at least until last year when I started to buy some plaid shirts.)

 

[travlar]

Originally posted by Randy Tyler:
As I said before let's assume that mines operate in a manner similar to missiles in the HighGuard combat system, it's the closest thing. So one of the 6424 mines detects an incoming ship, let's say a small Fer-de-lance escort, and begins it's attack on the ship. A factor one missile (there's only one missile) needs a base of six to hit. The ship's computer model 9 adds +9 to that (the missile has no computer), the ship's agility is 6 so add another +6, the target size code is K so add another +1, and the missile is operating at short range adding another +1 to hit, so you would have to roll 23+ to hit (on 2d6). No chance! Even if you had a missile attack factor of 9 because of the ship's computer and agility you still have no chance to hit (17+ on 2d6).

The use of mines that are based on the missile combat in HighGuard are only going to be effective against ships with small computers and low agility. If your mines are effective against the 'raiding' ships due to low computer model and low agility then, IMO, such 'raiders' aren't going to be much of a threat to your system in the first place. 200 Fer-de-lance DE's might disrupt your tanker convoys and destroy your 'remote' industrail complex but probably couldn't do much damage to the mainworld. If the mainworld has deep meson sites, even a few hundred built at low tech levels, I doubt that such 'raiders' would ever come within combat ranges of the mainworld.

So once again I will say that mines are ineffective and wasteful of funds.

IMO

While the mine won't have a computer, it would be pretty easy to have computer and sensor stations that give the mine a model 9. Also, the ship's agillity would at least be reduced by the GGs gravity well, and the target won't have much, if any reaction time. Also, you could make the mines very small, and have them move into a position where the fuel scoops will scoop it up, and then it can explode inside.

Originally posted by Randy Tyler:
Let's go over some of the points.

Refueling points - three gas worlds
The idea of defending the three gas giants with the intent to prevent refueling by the 'raiding' force is absurd and insane. There is no practical way to prevent gas giant refueling. Because of the size of gas giants and their number in system the number of ships required is prohibitively high. The use of a smaller number of ships, a squadron for example, with the intent to deter or disrupt refueling operations by a raiding fleet is wasteful of resources that should be used defending more strategically important potential targets. If the board continues to insist that all three gas giants be defended then they will be responsible for the disaster when the system defenses are spread too thin to offer adaquete protection for the mainworld. Though it might end my career I would question the compentence of the military strategic review board and ask: are they experienced line officers or amatuer, armchair adolescent strategists whose only experience is by playing paper map and cardboard counter wargames? The gas giants should not be defended.

Actually, against a raiding fleet a handful of SDBs would do a good job. If they send in fuel shuttles; the SDBs kill them. If they give them a strong enough escort that the SDBs can't safely attack; then the mines will do some damage, and the SDBs can probably launch missiles at the refueling fleet without being detected.

 

[RandyT0001]

Originally posted by Kaale Dasar:
While the mine won't have a computer, it would be pretty easy to have computer and sensor stations that give the mine a model 9.

I decided to use HGS to come up with some type of mine sensor pod to detect ships and direct them to targets.
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Ship: Mine Sensor Pod
Class: Mine Sensor Pod2
Type: Mine Sensor Pod
Architect: TylersTools
Tech Level: 15

USP
Sc-0401Q91-000000-00000-0 MCr 180.750 50 Tons
Bat Bear Crew: 1 (Robotic)
Bat TL: 15

Cargo: 2.000 Fuel: 12.000 EP: 12.000 Agility: 0
Fuel Treatment: Fuel Scoops

Architects Fee: MCr 1.808 Cost in Quantity: MCr 144.600
(Does not include the cost of the robotic pilot.)</pre>[/QUOTE]Given military detection ranges are about 600,000km one would need about seven to cover Neptune and about 57 to cover Jupiter. These pods have no defenses and very limited mobility; they would be vulnerable to fighters launched from the 'raider' force and their computers could be quickly degraded by nuke missiles launched from the main ships. The rules don't permit fib computers on small craft (according to HGS) and making the pod bigger and using a fib computer at that point merely increases the cost from MCr 145 to probably almost twice that. Let's say the system has one LGG and two SGG's that would entail an additional cost of about BCr 11 for the 71 sensor pods.

Also, the ship's agillity would at least be reduced by the GGs gravity well, and the target won't have much, if any reaction time.

Though HG does not quantatively state how much skimming affects agility it does say "especially vulnerable" so I'd be willing to accept the agility of a ship is cut to a third (round down) of it's normal agility when skimming. Far-Trader's post about mines spaced out with a 60,000km range is what I was basing the post on. His 6G mine(missile) would take about 23 minutes to travel to it's furtherest 'target area' to intercept. That's slighty over one HG combat turn, enough time to react. In order to seed a gas giant with enough mines to make the reation time so small as to be virtually 'non-reactive' in nature one would need billions of mines costing trillions of Cr's.

Also, you could make the mines very small, and have them move into a position where the fuel scoops will scoop it up, and then it can explode inside.

The 'missile-based' mine is pretty small anyway at 50kg(IIRC) in size. If you can detect and track mines in normal HG combat and if you assume that the detection ranges for the pods are not degraded by the GG atmosphere (if they can detect you, then you should be able to detect them) and that the mines guidance is unaffected then it is highly unlikely that a ship will 'scoop up' unidentified mines. IMO

Actually, against a raiding fleet a handful of SDBs would do a good job. If they send in fuel shuttles; the SDBs kill them. If they give them a strong enough escort that the SDBs can't safely attack; then the mines will do some damage, and the SDBs can probably launch missiles at the refueling fleet without being detected.

The SBD's would have to be stationed inside the GG atmosphere if they want to have a reasonable chance to intercept the fuel shuttles. But I seriously doubt that the 'raiders' will be depended on fuel shuttles because of their vulnerablity to SBD's and will more likely consist of ships that can undertake skimming on their on. A couple of SBD's might be able to take out a Fer-de-lance DE's but as the ships get larger the chances of the SBD's doing serious damage decreases. IMO

YMMV

 

[RandyT0001]

Thinking about the industrial complex I decided to do some research about the consumption of certain resources that a world with billions of inhabitants might have. The figures below are based on Earth's consumption today. Adjustments for consumption increases due to higher world TL would have to be made.

All of the metals except for the Platinum Group Metals are recycled by various but substantial percentages based upon the specific metal in question. On Earth a small fraction of the organics are recycled (plastics mostly). On a higher TL world more recycling is probable, especially of the organics. On this hypothetical mainworld where the ecology is very important we might assume that 80% of the organics and metals are recycled but that would be done in the industrial complex. Concrete can be recycled for it's aggregate (rocks) but cement cannot be recycled.

Assumptions on a mainworld's consumption of certain resources

Non-metals
Cement(1) = 2,300,000,000 tons/yr (d=3.2) = 51,000,000 dton

Organics(*)
Coal(2) = 1,200,000,000 tons/yr (d~0.9) = 95,000,000 dton
Natural gas(3) = 1,100,000,000,000 m^3 = 79,000,000,000 dton
as liquified natural gas = 132,000,000 dtons
Petroleum(4) = 6,100,000,000 barrels/yr = 69,000,000 dton
(m^3=6.3 barrels)

Selected Metals
Aluminum = 24,000,000 tons/yr (d=2.7) = 635,000 dton
Chromium = 4,000,000 tons/yr (d=7.2) = 40,000 dton
Cobalt = 27,000,000 tons/yr (d=8.7) = 220,000 dton
Copper = 13,000,000 tons/yr (d=8.9) = 105,000 dton
Iron = 1,000,000,000 tons/year (d=7.9) = 9,050,000 dton
Lead = 6,000,000 tons/yr (d=11.4) = 37,600 dton
Manganese = 7,000,000 tons/yr (d=7.2) = 70,000 dton
Nickel = 1,000,000 tons/yr (d=8.9) = 8,000 dton
Platinum Group Metals = 500 tons/yr (avg d=19.7) = 1.8 dton
Tin = 300,000 tons/yr (d=7.3) = 3,000 dton
Titanium = 4,000,000 tons/yr (d=4.5) = 63,500 dton
Zinc = 8,000,000 tons/yr (d=7.1) = 80,500 dton

d=density

(*)The figures for the organics have been adjusted to reflect usage in a non-energy sector capacity (i.e. not used in electrical power generation, home/commercial heating/cooking, nor as transportation fuels).
(1)Cement is made primarily from limestone. Limestone was made by tiny sealife millions of years ago then compacted into rock by overlay. If the mainworld does not have a history of sealife and shallow seas then the existence of limestone on the world is questionable. Some types of volcanic ash exhibit the same qualities of cement.
Cement consumption may be skewed because on Earth China is experiencing a significant economic and construction boom and is building the huge concrete Three Gorges Dam.
(2)Coal was produced over the course of millions of years by the dead vegetation that was overlaid and compacted. If the mainworld does not have a history of large quantities of vegetation the existence of coal on the world is questionable.
(3)The accepted theory is that all natural gas on a world is/was formed by a biological process. The large deposits deep undergound were formed millions of years ago. If the world does not have a history of life millions of years old then it will be dependent on oceanic methane hydrate deposits which were not formed millions of years ago.
(4)The accepted theory is that all petroleum on a world was formed by a biological process. The large deposits deep undergound were formed millions of years ago. If the world does not have a history of life millions of years old then the existence of large petroleum fields is questionable.

 

[veltyen]

Depending on the TL of the mainworld a lot of the resources will change to different versions. The same can be seen here, with aluminium replacing other metals for many uses due to technical innovation.

Power is the key. Organic sludge with enough massaging can be turned into most other types of organic sludge. This solves the problem you may have with organic derived base materials (cement, oil). Enough CHON, along with the other elements needed and power and you can manufacture nearly anything. Once you have enough organic material on the mainworld you can just continue to recycle the system.

Metals are harder (no pun intended). Except at very high TL's using a fusion process to create metals is going to be exceedingly wasteful. At very high TL's this could be what the industrial platform is for, using extraordinary amounts of power to create new metals from lower elements. This would have immense power needs, and is likely to end up with large amounts of radioactive materials just sitting around before being refined again. This is certainly a good reason to do the refining "off shore".

Of course, if there are metals in system that don't have to be fusion forged they should be used in preference to creating the metals from scratch. At low TL's that creates another reason for the platform, that being refinement and extraction of asteroids and other bodies. This too can have unpleasant spin off materials (again radioactives mainly, and some poisons).

 

[RandyT0001]

Even with 100% recycling you will have to find the raw material needed for increases in consumption due to population and/or economic growth. That might be a 2-5% increase each year. If the system has a planetoid/asteroid belt then one could use the asteroids that cross the mainworld's orbit as a source. (From what I understand it is the perbutations by Jupiter upon our asteroid belt that caused some to change orbit and become Earth crossers. It would have to be an unusual circumstance, IMO, not to have inner orbit crossing asteroids if there is an asteroid belt in the system with three gas giants present.) If there are no asteroids then the material will have to be extracted from other planets and/or their moons and delivered to the industrial complex. Delivery could be accomplished with the use of modest sized 6G 'tugs' that attach to raw material chunks about 5x their size which transport it to the industrial complex. (There are a few variations of this I would use depending upon the actual travel distances involved.)

In any case I question the need to have the industrial complex in 'deep space'. If the mainworld has a moon, even one the size of our asteroids Iris or Juno, I think it is the most logical place to build the industrial complex on (or more correctly in, as in about 0.5km underground). The moon's orbital distance should be more than adequate to prevent industrial accidents from becoming ecological disasters on the mainworld. Even if the mainworld does not have a moon I think it's makes more sense to locate the industrial complex (built as scores of units, each with a limited capability to maneuver (1G)) in high orbit (five to ten planetary diameters) around the mainworld. Building the industrial complex in such close proximity to the mainworld means the mainworld's defenses can protect the complex also.

I really cannot conceive of any practical nor logical reason why the industrial complex would be located further out in 'deep space'.
IMO

 

[veltyen]

I really cannot conceive of any practical nor logical reason why the industrial complex would be located further out in 'deep space'.

I can think of one. A collection and refinery platform located in an asteroid belt, or around one of the gas giants, or if you're really fussy at a location that minimises the total distance travelled. That assumes that bulk in-system freight is moderately expensive to make a lot of sense though.

If that is the case it becomes more a sub-colony of belters in system that you are protecting. The industrial platform becomes a collection/refining/logistics/repair/supply platform and the kernel of a belter community. This makes more sense to me.

 

[RandyT0001]

There are generally three types of asteroids that exist in our asteroid belt that are common and offer the potential for resources. I will assume that this hypothetical system is similar.

C-type: These asteroids account for about 75% of the asteroids in our system. C-type asteroids are thought mostly to consist "carbonaceous chondrites," a mixture of rock and tar that has a composition much like the sun, minus the hydrogen and helium.
S-type: This type includes about 17% of known asteroids. Its composition is metallic nickel-iron mixed with iron- and magnesium-silicates.
M-type: This type includes most of the rest of the known asteroids. (Making up about 7% of the total number of asteroids?) Most are thought to consist of nickel-iron with a small amount of iron- and magnesium-silicates.


Per million metric tons of an 'average' or 'typical' C type of asteroid. Units are in metric tons.

Oxygen (O) = 410,000
Iron (Fe) = 220,000
Silicon (Si) = 140,000
Magnesium (Mg) = 120,000
Sulfur (S) = 41,000
Hydrogen (H) = 24,000
Carbon (as Graphite) (C) = 15,000
Nickel (Ni) = 13,000
Calcium (Ca) = 11,000
Aluminum (Al) = 9,800
Sodium (Na) = 5,600
Chromium (Cr) = 3,100
Manganese (Mn) = 2,800
Nitrogen (N) = 1,400
Phosphorus (Red) (P) = 1,100
Potasium (K) = 710
Cobalt (Co) = 600
Titanium (Ti) = 550
Chlorine (Cl) = 380
Zinc (Zn) = 180
Copper (Cu) = 110
Fluorine (F) = 89
Vanadium (V) = 62
Germanium (Ge) = 21
Selenium (Se) = 13
Strontium (Sr) = 8.9
Gallium (Ga) = 7.8
Zirconium (Zr) = 6.7
Scandium (Sc) = 6.5
Rubidium (Rb) = 3.3
Barium (Ba) = 2.8
Tellurium (Te) = 2.1
Yttrium (Y) = 1.9
Arsenic (?) = 1.8
Lithium (Li) = 1.7
Boron (B) = 1.6
Lead (Pb) = 1.4
Tin (Sn) = 1.2
Molybdenum (Mo) = 1.2
Bromine (Br) = 1.2

Platinum Group Metals
Platinum (Pt) = 1.0
Ruthenum (Ru) = 0.83
Palladium (Pd) = 0.67
Osmium (Os) = 0.67
Iridium (Ir) = 0.55
Rhodium (Rh) = 0.18

Of special interest to Belters in Traveller
Lanthanum (La) = 0.29


Since most of the M-type of asteroids consist of about 98% nickel-iron with iron being about 75% of the asteroid we can assume that one million tons of a 'typical' type M asteroid will yield (about) 735,000 tons of iron, 245,000 tons of nickel, and the last 20,000 tons of various amounts of magnesium, silicon, and oxygen. An S-type asteroid will have less nickel-iron and more magnesium silicates changing the percentages accordingly.

In our outer system, generally at distances in the orbital range of the gas giants, there are the inactive cores of comets. These cores have many similar characteristics to C-type of asteroids. They are important in that they may be comparitively rich in "ices", the frozen gases that consist of the elements CHON. Though some might consider these an excellent cource of such gases I think it would be more productive to recover them by skimming gas giants and discarding the excess molecular H and He.

Though I wouldn't use it myself due to it's defensive shortcomings, huge target size, and other factors (it just begs to be shot), I did design a 1Mt ship (TL D) to get an idea of it's basic cargo capacity.

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Ship: BUFF
Class: Huge Ore Transport
Type: Huge Ore Transport
Architect: TylersTools
Tech Level: 13

USP
Ot-Y413374-000000-00000-0 MCr 368,664.500 1 MTons
Bat Bear Crew: 5100
Bat TL: 13

Cargo: 563,841.000 Fuel: 230,000.000 EP: 30,000.000 Agility: 2
Shipboard Security Detail: 1000
Fuel Treatment: Fuel Scoops and On Board Fuel Purification

Architects Fee: MCr 3,686.645 Cost in Quantity: MCr 294,931.600</pre>[/QUOTE]The ship is designed to jump from the mainworld to the mining site, fill up with ore, then jump back to the mainworld in order to minimize exposure to possible attack.

Let's say that 563,000 dtons are used for transportation (the rest is used for spare drill bits, extra beer, etc.) of raw matrial, a big, unprocessed chunk of a C-type of asteroid. The statistacal average density of C-type asteroids equals 1.2g/cm^3(1), therefore BUFF can transport about 9.45 million metric tons of material. If the mainworld has 100% recycling capability and only needs to mine material needed for population/economic growth of 5% then BUFF can deliver the following percentages (of the 5% growth increase needed) in one trip taking about two weeks.

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Aluminum = 7.7% 25 trips = 192.5%
Chromium = 14.6% 25 trips = 365%
Cobalt = 0.4% 25 trips = 10%
Copper = 0.16% 25 trips = 4%
Iron = 4.2% 25 trips = 105%
Lead = 0.004% 25 trips = 0.1%
Manganese = 7.6% 25 trips = 190%
Nickel = 248% 25 trips = 6200%
Platinum Group Metals = 147% 25 trips = 3675%
Tin = 0.076% 25 trips = 1.9%
Titanium = 2.6% 25 trips = 65%
Zinc = 0.43% 25 trips = 10.75%</pre>[/QUOTE]One trip by BUFF carrying a chunk of M-type asteroid would deliver (about) the following percentages (like above).

Iron = 13.9%
Nickel = 463%
Others = ?

Supplemental mining and (possibly) on-site processing operations (but mobile like BUFF) would have to be undertaken to insure that the demands for the rarer metals such as lead, tin, copper, etc. are met. But I'll address that in another post later.

(1)Moons and Planets, 4th ed

 

[veltyen]

I've always wondered about jumping in system. The awesome acceleration of the standard traveller drive makes it a little awkward.

In a week, a 1G ship can travel a light hour (stop to stop). It reaches 0.01 C at turnover. Considering how cheap realspace travel is to jump travel, anything closer then that is a no brainer, use in-system ships. This is linear on acceleration, 6G can travel 6 light hours in the same time and way. I'm ignoring any relativistic effects (they'd be minute anyway).

An AU is 500 light seconds (approximately). The furthest objects of interest in this system sit up to 50AU out from the primary, which is about 7 light hours. Or in other words, about 8 days travel for a fast ship, or 3 weeks for a 1G ship.

Now if you allow asynchronous ships, that changes things again. A ship that was 1kdTon/6G on the way out, and 6kdTon/1G on the way back has certain advantages. The time taken for a 6G ship to cover the same distance as a 1G ship is 0.4 (ie. if it takes a 1G ship 10 days to travel, it will take a 6G ship 4 days), so the limiting distance to save time over a jump ship is instead 1.7 Light hours/12.5AU. That's past Saturn, but still a way from Uranus.

Appendix
Ship sketch of asynchronous Ore Tug. This ship contains both drives (rather then using the same drive from both movement types). Designed under T20.

Ore Tug
Hull: 6000 dTon closed design
Tech Level: D (13)
Computer: Model/3
Drive: Heavy lift, 1G x 6kdTon (120 dTon)
Drive: Fast Transit 6G x 1kdTon (170 dTon)
Powerplant: 65 EP (enough to run one drive) (65 dTon)
Fuel: 8 weeks duration (130 dTon)
Hardpoints: 10 (normally unarmed)
Small Craft: 4 x 30dTon Utility craft
Crew: 11 Officers, 31 crew

Fittings
30 Staterooms
100 low berths
Engineering Shop
Sick Bay
4 Autodocs
6 Airlocks

Cargo
Life Support: 33 dTon (2600 person weeks)
External Ore Pod: 5000 dTon

Cost: 750 MCr (including subcraft and some customisation)

 

[RandyT0001]

Ugh, another post by Randy!

Near Earth Asteroids
There are three families of NEAs:
1. The Amors, which have average orbital radii in between the orbits of Earth and Mars and perihelia slightly outside Earth's orbit (1.017 - 1.3 AU). Amors often cross the orbit of Mars, but they do not cross the orbit of Earth.
2. The Apollos, which have average orbital radii greater than that of the Earth and perihelia less than Earth's aphelion.
3. The Atens, which have average orbital radii closer than one astronomical unit and aphelia of greater than Earth's perihelion, placing them usually inside the orbit of Earth.(1)
</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">Amor asteroids

Name Mass(tons) Class q/Q(AU) P(yr) Trips
Eros 7.2*10E12 S 1.1/1.8 1.76 761,900
Albert 14,000,000,000 S 1.2/4.1 4.27 1,481
Ganymed 3.3*10E13 S 1.2/4.1 4.34 1,375,661
Amor 3,500,000,000 C or S 1.1/2.8 2.66 370


Apollo asteroids

Name Mass(tons) Class q/Q(AU) P(yr) Trips
Hermes 67,000,000 S 0.6/2.7 2.13 7
Itokawa 35,000,000 S 0.9/1.7 1.52 3.7
Golevka 210,000,000 (S?) 0.9/4.0 3.95 22.2
Castalia 500,000,000 S (a=1.1) 1.10 52.9
Toutatis 50,000,000,000 S 0.9/4.1 4.01 5,291
Phaethon 1.4*10E11 C 0.1/2.4 1.43 14,814
Bacchus 3,300,000,000 S(Q) 0.7/1.5 1.12 349
Apollo 5,100,000,000 S(Q) 0.6/2.3 1.78 539
Geographos 26,000,000,000 S 0.8/1.7 1.39 2,751


Aten asteroids

Name Mass(tons) Class q/Q(AU) P(yr) Trips
Amun 16,000,000,000 M 0.7/1.3 0.96 1,693
Aten 760,000,000 S 0.8/1.1 0.95 80</pre>[/QUOTE](1)Quoted from Wikipedia, data from Wikipedia
q = perihelion (closest approach to the Sun)
Q = aphelion (furtherest point from the Sun)
P = orbital period (in Julian years of exactly 365.25 days)
a = semi-major axis

Hundreds of NEA's have been found so far and the search continues. The ones above were selected because they have data about the asteroid's mass and class. Most present day operations and studies are primarily focused on identifying and tracking NEA's in order to try to predict potential collisions with the Earth. Astronomers use an asteroid's albedo to try to identify it's type. An asteroid's albedo may be high in the radar segment of the EM spectrum due to high metal content and this might explain the high incidence of S-type of asteroids listed above. Since astronomers depend more on the visible EM segment to identify C-type asteroids and many NEA's are small it makes it more difficult to positively identify C-type asteroids. I'm going to assume that most NEA's are C-type and comprise about 75% of the total with another 24% as S-types and M-types similar to the averages of the system's overall averages.

Excluding Ganymed (which, IMO, is probably a rare size that would skew the average too much) I'm going to use the list above to help determine that the 'average' size of a 'typical' NEA is about 790,000,000,000 tons each. Given the hundreds that have been found (and the fact that there may be thousands that have yet to be discovered) I'm going to assume that at any given time that there are about 5-10 NEA's within 0.2-0.4AU's of Earth. For the sake of arguement let's reduce the size of these asteroids by a factor of one hundred from the 'average'. Each is now 7,900,000,000 tons in size and each of these 5-10 asteroids can supply enough material for about 836 trips by a BUFF ship (see previous post). Each of these roughly 8 billion ton asteroids could supply the mainworld with enough material to last over twenty-five years (given an economic/population growth based increase in the demand for raw material of 5%).

What is my purpose for all this? If the system of the hypothetical mainworld is similar to ours with a planetoid belt and gias giants (and many Traveller star systems have both) that perturb the orbits of some of those planetoids then there will likely be hundreds of inner system asteroids like the Amor, Apollo, and Aten asteroids. Basically it means that you wont have to go out into deep space (more that 1 AU from the mainworld, probably much less) to mine asteroids for your needs. As an asteroid leaves the area mining operations are shifted (probably about every three months) to another asteroid that is approaching the area and will be easier to exploit for the next few months.

If the system of this hypothetical mainworld is similar to ours I question the need to have an industrial complex located in 'deep space'. I think it makes more sense to have the complex close to the mainworld, in high orbit or on a mainworld's moon.
IMO

Though most are probably dreading it there is more to come.

 

[robject]

Originally posted by far-trader:
</font><blockquote>quote:</font><hr />Originally posted by Andrew Boulton:
</font><blockquote>quote:</font><hr />Originally posted by far-trader:
And just how hard would it be to actually grab a comet and settle it into a nice handy, safe, stable orbit?

With fusion and thruster plates, pretty easy. </font>[/QUOTE]Hmm, I'm not so sure. If the comet is a solid body maybe but if it's a collection of small (relatively) bodies, or a fractured and unstable body it's gonna require more than just landing a fusion reactor and thruster plate on it.
</font>[/QUOTE]Well this is a good point -- comets aren't solids. So unless you have a "bucky-ball"-style object-catcher, grabbing one may be difficult. So we're more or less back to the fuel tanker concept.