This is a whole new area for v3.2 and it's based on some suggestions made by Matt Wadwell several versions ago. Until last night I hadn't figured out a good way to handle this but the lightbulb has finally gone on
When you go to the Missile Design window you can now choose to design either missiles or buoys. They are both treated as missiles in the game and function under exactly the same rules, the difference is purely in design. Missiles have all of the options that they previously had. Buoys can't have warheads, engines, fuel or agility and instead gain reactors. A reactor can power a buoy for a number of months equal to the reactor power of your latest reactor tech multiplied by the Missile Size Points (MSP) of the reactor. For example a Pebble Bed Reactor has three points of power per HS, so it also has three months of endurance per MSP. If you have 2 MSP on the buoy, it will have an endurance of six months. You can add sensors to a buoy design, just like a missile, so you can create bouys with active, thermal or EM sensors, or a combination of the above. Once off the missile design window, buoys become just like any other missile. You can build them in ordnance factories, you can add them to ship's magazine and you fire them from missile launchers, although they just remain where you fire them. Here is a simple example of a small thermal sensor buoy. It has 1 MSP of thermal sensors and 2 MSP of reactor. It would be ideal for leaving at a planet or close to a jump point for monitoring traffic.
Thermal Sensor Buoy
Buoy Size: 3 MSP (0.15 HS) Armour: 0
Reactor Endurance: 6 months
Thermal Sensor Strength: 0.25 Detect Sig Strength 1000: 250,000 km
Cost Per Buoy: 1.45
Materials Required: 0.25x Uridium, 1.2x Boronide
Development Cost for Project: 145RP
Here is where it starts to get interesting. You can create missiles with buoys in the second stage or vice versa. So lets create a new Heat-seeking missile using the normal missile design rules (actually this is using the new more granular missile design rules so it is 1 MSP sensor strength, 1 MSP warhead, 0.01 MSP Fuel and 0.99 MSP Engine).
Heat-seeker
Missile Size: 3 MSP (0.15 HS) Warhead: 4 Armour: 0 Manoeuvre Rating: 10
Speed: 10600 km/s Endurance: 1 minutes Range: 0.7m km
Thermal Sensor Strength: 0.25 Detect Sig Strength 1000: 250,000 km
Cost Per Missile: 1.778
Chance to Hit: 1k km/s 106% 3k km/s 30% 5k km/s 21.2% 10k km/s 10.6%
Materials Required: 1x Tritanium 0.25x Uridium 0.278x Gallicite Fuel x25
Development Cost for Project: 178RP
If this missile is not under shipboard guidance, it will automatically attack any ship with a thermal signature that does not belong to the race that launched it (and when I get started on IFF, maybe that won't be 100% certain). Now lets take three of these missiles and put them in a sensor buoy that will sit quietly for months and then release them when it detects a thermal signature within its second stage separation range.
Captor Mine
Buoy Size: 12 MSP (0.6 HS) Armour: 0
Reactor Endurance: 6 months
Thermal Sensor Strength: 0.25 Detect Sig Strength 1000: 250,000 km
Cost Per Buoy: 6.784
Second Stage: Heat-seeker x3
Second Stage Separation Range: 150,000 km
Materials Required: 3x Tritanium 1x Uridium 0.584x Gallicite
Development Cost for Project: 678RP
You can leave this baby near a jump point (for example) and if someone pops through for a look the buoy will detect them (based on their thermal signature) and if they are within separation range, the buoy will release the three heat-seekers, passing on the location of the target. The heat-seekers (as with any other second stage missile) will head for the target location given to them by the first stage (the buoy in this case) and will starting trying to detect the target themselves. As soon as they do, they home in and attack. I just ran this exact scenario using these mines at a jump point and it worked perfectly. As you can imagine, the possibilities for mine design and mine warfare are considerable. The beauty of it is that it all works under the existing missile rules.
In the course of making these changes I have reviewed and completely overhauled the code used by missiles to select their own targets. In the past they looked for nearby existing sensor contacts. Now when a missile needs to select a target, Aurora runs a complete sensor check for the system using only the missile's sensor. It's much more accurate and much more playable.
One immediate concern I had was that mine warfare could get fiddly as you micromanage launching the mines at various locations around a jump point. Therefore I have added a new fleet order that allows you to fire missiles at a waypoint, jump point or a system body. This order does not require any fire control assignment as the missiles are launched without guidance from the parent ship. In fact, using this order the ship doesn't even need a fire control system. The ship will launch any missiles that are currently assigned to a missile launcher. So if your ship had six launchers and you just wanted to drop off a few solitary sensor buoys, you assign the buoy to one launcher and leave the others unassigned. When the ship reaches a location and carries out the order, only the assigned launcher will drop off a buoy. If you wanted to leave pairs of thermal and EM buoys, assign each type of buoy to a different launcher. Reloading is still a factor so if you try to drop off mines close together the ship will wait until its launchers reload before dropping its mines/buoys and moving on. With this new ability in mind I created a new size 12 missile launcher to lay the captor mines.
Minelaying System
Maximum Missile Size: 12 Rate of Fire: 360 seconds
Launcher Size: 12 Launcher HTK: 6
Cost Per Launcher: 48 Crew Per Launcher: 120
Materials Required: 12x Duranium 36x Tritanium
Development Cost for Project: 480RP
This is a normal missile launcher designed in the normal way. I just gave it a different name and only bothered with the lowest reload rate. I then created a new Minelayer class using the above system. Note this ship doesn't even have a fire control system or any sensors. It is designed to travel around a set of waypoints you designate and drop off mines (or sensor buoys). In playtesting, it dropped a pair of mines near a ship of another race. The mines immediately detected the other ship and launched their missiles, which homed in and attacked. All of this happened automatically after I gave the drop off order and advanced time.
Tribal class Minelayer 7000 tons 524 Crew 718.4 BP TCS 140 TH 160 EM 0
1142 km/s Armour 1-32 Shields 0-0 Sensors 1/1/0/0 Damage Control Rating 4 PPV 24
Annual Failure Rate: 98% IFR: 1.4% Maintenance Capacity 257 MSP Max Repair 50 MSP
Magazine 1464
E90 Nuclear Pulse Engine (4) Power 40 Efficiency 0.90 Signature 40 Armour 0 Exp 5%
Fuel Capacity 150,000 Litres Range 42.8 billion km (434 days at full power)
Minelaying System (2) Missile Size 12 Rate of Fire 360
Captor Mine (120) Speed: 0 km/s End: 180 days Range: 0.1m km Warhead: 0 MR: 10 Size: 12
I am now looking at implementations of the opposite idea. A missiles with a buoy as the second stage. This will allow you to create long-range missiles that deliver a sensor buoy that can remain on station for months or years. It will be a great way to scout out your opponents in a stealthy way. You get the stealthly advantages of recon probes and the long term staying power of ships. I am also looking at putting geological sensors on missiles so you could create a geological sensor buoy, put it on a large first stage missile and fire it at a distant planet to carry out a geological survey. This would also give you the option to provide geological survey probes to non-survey ships and give them a limited surveying capability. I'll post more on these last two ideas once I have done some play-testing.
Steve