My First Real Attempt At An Asteroid Miner

[xenoscepter (OP)]

 - The Century-Class is my first (real) attempt at an Asteroid Mining Vessel.    It works by being tugged into position by it's three Decade-Class Freighters.    The Freighters then dock inside the Century-Class ship for five years years while it mines out the ore.    During this time they top off their tanks, and after the five years they tug it home and deliver the ore to anywhere within two years of the drop-off point.    Without a resupply point, the Century and her three attending Decades can operate up to a year out.    With resupply.   .   .    well, that's a horse of a different color.   

 - If my understanding of Mining Mechanics is off, please by all means correct me in the reply thread.    And as per usual, any criticism, feedback or opinions you might have are welcome.    Thanks!

- The Century-Class Asteroid Miner

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Century class Asteroid Miner    518,000 tons     5995 Crew     28399 BP      TCS 10360  TH 0  EM 0
1 km/s     Armour 2-574     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 300     PPV 0
Maint Life 7.02 Years     MSP 160280    AFR 7155%    IFR 99.4%    1YR 5687    5YR 85310    Max Repair 120 MSP
Intended Deployment Time: 72 months    Flight Crew Berths 615   
Hangar Deck Capacity 75000 tons     Cargo 25000    Cargo Handling Multiplier 30   
Asteroid Miner: 60 module(s) producing 600 tons per mineral per annum

Fuel Capacity 24,000,000 Litres    Range N/A

This design is classed as a Military Vessel for maintenance purposes



- The Decade-Class Freighter

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Decade class Freighter    25,000 tons     203 Crew     1608.6 BP      TCS 500  TH 700  EM 0
1400 km/s     Armour 3-76     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 6     PPV 0
Maint Life 2.56 Years     MSP 3241    AFR 833%    IFR 11.6%    1YR 690    5YR 10355    Max Repair 100 MSP
Intended Deployment Time: 48 months    Spare Berths 3   
Cargo 5000    Cargo Handling Multiplier 5    Tractor Beam     

BFE Drivestar (4)    Power 175    Fuel Use 65%    Signature 175    Exp 10%
Fuel Capacity 8,610,000 Litres    Range 95.4 billion km   (788 days at full power)

This design is classed as a Military Vessel for maintenance purposes


[Erik L]

Are you sure it's only going to take 2 years to tug out and back?

[xenoscepter (OP)]

. . . no. . .

[xenoscepter (OP)]

Wait a minute. . .  Can I use three tugs on one ship? Does that work? If not, this design is a fail. . .

[amram]

I don't know if you can tractor with multiple ships or not.

But if you want to know how much grunt you need to drag something around at the speed you want, there's a little bit of math you can do to know for sure before you get started.

You have a barge, the century class, at 518k tons.  You have a tug that masses 25k tons, and puts out 4*175EP, 700EP, for a speed of 1400km/sec.

So, the math.  You can calculate how fast you will go, speed=EP/tons*50000, or speed=EP/HS*1000, i'll stay in tons here.

So lets check your tug first, just to see.  700/25000*50000 = 1400, just as aurora said.

Now lets see about when its towing the barge.  700/(25000+518000)*50000 = 700/543000*50000 = 64.5km/sec

How far can that go in two years?  (days in aurora year)*(seconds in aurora day)*speed = 360*86400*64.5 = 2.006b km.  Or a little more than Earth to the far side of saturn's orbit.

If you want to know how much engine you need to hit a given speed, you can rearrange it:  speed/50000*tons = EP  Again, lets look at the tug to see it.  1400/50000*25000 = 700 EP, and it has 700 EP

So lets say you wanted to get to pluto in 2 years, that's 7.4b km. on average  distance/360/86400=km/sec, 7,400,000,000/360,86400=237.9km/sec.  So we need 238km/sec, minimum.

How much EP do you need to move the barge and tug at 238km/sec? 238/50000*543000 = 2585EP

On Nuclear Pulse, how much engine is that? 50 hull size 0.5 power engines are only 200 EP, so 13 of them for 2600EP.  32,500t just in engines....  but that's heavier than we did the math for....we need more engine, or a smaller barge.

Make your tug 60,000t and you'll need 2751EP, 14 of Nuclear Pulse size 50 power 0.5 will give you 2800EP, for a towing speed of 242km/sec.  You'll need 35000t in engines, leaving you 25,000 tons of ship to go with them for the cargo portion.

On Ion, you can get your needed speed on just 2/3 the engine, 10 size 50 power 0.5 ion drives get you 300EP each, 3000 total, and 25000t in engines.  for a 60kt tug towing the barge, thats a speed of 260km/sec, 8.1b km in 2 years.

btw, don't do all this by hand for each new design, spreadsheets every aurora player's best friend, lol.

[sublight]

Ok... let's suppose you spend a year tugging the miner out, five years of mining, and a year tugging the miner back.

In those 5+2 years you will mine 3000 * total_accessibility tons of minerals.
In the same period you suffer a maintenance failure on average once every time increment burning up to 160K maintenance supply units worth 40,000 tons of minerals. Even if the asteroid has perfect accessibility for every mineral this operation is going to run at a net loss.

Also if you plan to avoid maintenance losses by playing with the no-maintenance cheat option enabled you would still need a 518 kTon navel shipyard to build this monstrosity.

I'd suggest redesigning a civilian ship version without the hanger space, military engines, etc.


Lastly tugs only work correctly when you have only two ships connected by a single tractor link. Chaining 3+ ships together is game breaking in either the 'does not work' or 'provides free performance' direction.

[Michael Sandy]

First off, you don't need to have this beastie be military at all.  You don't need freighters to DOCK with it, because freighters don't care about maintenance or crew endurance.

As a commercial ship, there is very little call for spending so much duranium on armor, unless you need to move this through a nebula.

The procedure for using multiple tugs is Tug A tractors Tug B. The combined task group then tractors whatever.  Unfortunately, (or fortunately), the task group speed is determined ONLY by the first two ships in the chain.  This is an exploit, which I why I said 'unfortunately'.

Asteroid miners that are commercial don't care about crew endurance or maintenance beyond the mandatory 1 engineering space.

Also, you don't absolutely HAVE to build this in a shipyard.  You can build it with planetary industry if it is part of an Orbital Habitat.  Size matters for asteroid miners, because you may only have a few really good +Mining officers to magnify their output.

[Garfunkel]

First, only 1 tug can pull/push a ship at a time.

Second, the hangar idea is nifty but doesn't really work in Aurora. Better just make a mining station with nothing but AM modules. Don't make it too big so you can use a commercial shipyard to build them or make it really huge with an orbital habitat so that planetary construction factories can build it.

Third, the minerals it digs up are automatically stored on a colony on the body, so you can either have a mass driver delivered there to shoot them elsewhere or have a freighter(s) pick up the minerals later. Do not abandon the colony before you've collected your reward or all the ores will be gone.

Fourth, tugs are one of the few reasons to build high-power commercial engines, since they will only move occasionally, meaning that fuel savings aren't as important as for freighters, and because they really need every EP possible to move those big mining/harvesting/terraforming stations.

Fifth, deployment time does not matter for civilian ships except for geosurvey vessels and even they can kinda ignore it. So just keep it at 3 and RP that your shipping line(s) shuttle replacement crews to the stations every now and then. Or build an entertainment ship/station (remember to have 2 entertainment modules to avoid the bug!) to keep the workers happy!