I am re-reading the Starfire novel 'Crusade' and am at the part about Asteroids that have been converted into super OWP's. That got me thinking if it would be possible to tow an asteroid within a system to orbit of a planet. From there you could 'Install PDC' or equivalent and then tow it out to the location you wish to deploy it.
I guess there are few things to take into consideration:
1. Not sure if you do this already, but when generating asteroids do you give them a mass and three dimensions? That would mean you could only do this to asteroids that are a certain size - depending on how many PDCs you install.
2. it needs to have maintenance storage and usage but probably give it a highly reduced failure rate?
2.1 possibly allow maintenance facilities so it can act as a harbor for patrol vessels?
2.2 let it be designated as a collier, tanker and supply vessel/station.
3. Allow shields? or just rely on the natural armor of the asteroid used - depending on the (Duranium/Volume-of-asteroid) ratio? When installing the PDC ignore any inherent armor level added to the design.
4. When converted to an OWP remove it from the acceptable list of locations to drop off planetary sensors and mines.
5. Do not allow it to be transferred through a JP, even one with a gate.
6. ensure that any movement by tugs is slow but let multiple tugs pull it - depending on size of the asteroid
Sound feasible?
A fascinating idea. Not sure I can find a way to make it work but still fascinating to look at the possibilities. There are two sides to the question I think. The first is can you 'hollow out' an asteroid and turn it into a floating PDC. The second is can you move asteroids around. The reason to split this into two sections is that either by itself would be cool even if you couldn't do the other. Assuming you could move asteroids, I think the simplest way to approach this would simply be to avoid the complexities of 'hollowing out' and treat the asteroid as any other system body and place several PDCs on it. That allows asteroid fortresses with the minimum modification to the rules.
Anyway - lets look at moving asteroids first. Asteroids in Aurora do have diameter and mass, just like planets and moons. However all system bodies have been given a minimum mass 0f 0.0001 Earths, so as the first stage of looking at this idea I removed that minimum. Low masses will now be shown on the system view in scientific notiation to two significant figures to allow for realistic asteroid masses.
The formula used by Aurora to determine mass in Earth equivalents is: Mass = ((Radius / 6380) ^ 3) x Density (where Earth is density 1)
So Mars, which has a radius of 3400 km and a density of 0.71 would be Mass = ((3400 / 6380) ^ 3) x 0.71, which is 0.107 Earth masses and matches up with the Wiki entry for Mars
Mercury has a radius of 2440km and a density of 0.98: Mass = ((2440 / 6380) ^ 3) x 0.98, which is 0.055 Earth masses and also matches up with the Wiki
Lets try an asteroid with a radius of 20 kilometers and a density of 1: Mass = ((20 / 6380) ^ 3) x 1, which is 3.08055E-08 Earth masses.
Now we getting into scientific notation in terms of Earth masses so lets convert to metric tons instead. Earth is approximately 5.9736E+21 metric tons so if we multiply this by the Earth mass equivalent of our 40 km diameter asteroid, we get 1.8402E+14 metric tons or 184 trillion tons. So we won't be moving that then
How about an asteroid 1 km in diameter? Mass = ((0.5 / 6380) ^ 3) x 1, which is 4.81336E-13 Earth masses, or about 2.9 billion tons. Starting to get into the type of range we can visualise but still way beyond anything an Aurora tug could move. As we are getting into sizes that don't relate very much to something the size of the Earth, lets just double-check that figure by calculating the mass of a sphere 1 kilometer in diameter with the same density as the Earth (5.5153 g/cm^3)
4/3 x PI x 50,000cm^3 x 5.5153 =2.88781E+15 grams, or 2.88781E+12 kilograms or 2.9 billion metric tons.
How about an asteroid 100 meters in diameter (glossing over the fact there are no tiny asteroids in Aurora). 4/3x PI x 5000cm^3 x 5.5153 =2.88781E+12 grams, 2.9 million metric tons. Hmm, still gynormous but lets start looking whether a tug could move a ship that big. Here is large, expensive tug but certainly possible for a decent size Empire. Lets assume it tried to move a base as large as the asteroid, which would be a size 58,000 hull.
Brooklyn class Tug 27200 tons 2630 Crew 3465.8 BP TCS 544 TH 6000 EM 0
11029 km/s Armour 1-80 Shields 0-0 Sensors 1/1/0/0 Damage Control Rating 1 PPV 0
Annual Failure Rate: 5918% IFR: 82.2% Maintenance Capacity 80 MSP Max Repair 100 MSP
Tractor Beam
Ion Engine (100) Power 60 Fuel Use 70% Signature 60 Armour 0 Exp 5%
Fuel Capacity 500,000 Litres Range 47.3 billion km (49 days at full power)
The ship has 6000 engine power and the combined size of the ship and asteroid is 58,544. Towing speed is equal to Int((Engine Power/ Total Size) * 1000), which is Int(6000/58544)*1000) = 102 km/s
So to my surprise, this is starting to look possible for small asteroids. Bear im mind they are usually less dense than Earth as well so the actual towing speed would likely be slighty higher. If you can accept even slower towing speeds, the above ship could move a 200 meter asteroid (23 million tons) at 13 km/s. As I said earlier, there are no asteroids this small in Aurora. Adding them would be very straightforward though. They wouldn't contain minerals but they would be available to convert into some type of base, probably by building a PDC on them. The easiest way would be to ship in the parts then use engineers to assemble the PDC. Add some tracking stations and perhaps some troops and you have a semi-mobile base, probably with some serious armour protection. If it was handled that way, the only thing I would need to change would be the addition of small asteroids, the ability to tow them and perhaps some type of stationkeeping system so they could be deployed near jump points.
Steve