Orbiter Combat Simulator\Urwumpe Proposal A
This proposal describes a combat system using modular spacecraft, only allowing balanced ships to be attacked and damaged.
Overview
All magic is done inside a single DLL, which does everything from small projectiles to big space stations.
Important physics extensions like multiplayer and collision detection are handled inside the DLL, as this reduces the need for inter-DLL communication. Also, this appraoch turns all vessels, which are not designed and balanced for the space combat addon to non-combatants.
General assumptions
- Capital craft and bigger small craft have plenty electrical power because of fusion reactors on board.
- Effectivity of all systems is very high, requiring less thermal radiators (no space sail ships).
- Short range FTL travel is possible, but navigation complicated, because of unchartered waters. The concept is named parallel space.
Command hierachy
All ships have a position in the hierachy of the fleet. This does not automatically have effect on players (or AI), but can be used for scoring and assigning the squadrons to fleets.
Construction/Ship design
All objects consist of a basic skeleton (Structure), an external protection hull and the internal subsystems.
Object classes are:
- Projectiles
- Missiles/Rockets
- Small craft
- Capital craft/Stations
Projectiles are unguided, unpropelled objects, which can have payloads like sensors or warheads.
Missiles are propelled objects, which can have a guidance system. They are always unmanned.
Small craft are usually manned spacecraft, which have a simple single part structure. They only have a very small crew (1-4). They get used as short range transports and auxillary vessels.
Capital craft are large active spacecraft, which have a huge multi-part structure as basic skeleton.
Subsystems are installed on hardpoints in the structure. Its possible to define rotation angles for such hardpoints.
Its not possible to create free hierachies of structures - each skeleton part has a special fixed position where it can be used, Eg front or aft section.
The aft section always contains propulsion elements.
Movement
Usual propulsion happens by the use of He3 fusion propulsion, without inert mass injection. A special gamma ray absorbing crystal in each engines makes it possible to create vast amounts of electrical power, which gets used to accelerate the exhaust plasma further towards high speeds. (exhaust velocity around 125,000 m/s)
RCS uses a high powered electrothermal (resistojet) approach, vaporizing a liquid in the noozles for extra thrust and ISP (iSP around 15,000 m/s, power per thruster between 750 kW and 75 MW)
For faster strategic transfers, a heim drive is installed in bigger crafts. Because of its neccessarily huge size and mass, its not very popular for military ships, limiting it to massive carrier craft and biggest warships. On civilian vessels, such drives only appear on experimental craft and are rarely used for entering parallel space.
I had choosen the heim quantum theory based drive system, because its currently one of the best researched possible-faster-than-light movement systems. Yes, its still only slightly better than a warp drive. At least in the fact, that the papers available contain numbers and formulas, for implementing it in Orbiter. Many technical assumptions, like the electrical flow densities used, are also already expected for realistic fusion reactors, but the existance of graviphotons is still unsure.[1][2]
Sensors and detection
Sensor data includes the estimated travel time of the information.
Sensor types used are:
- IR/optical telescopes
- IR dragonfly eyes (large semispherical sensor arrays, which can detect IR activity like thrusters in a large FOV)
- phased array radar (nothing to explain)
- passive EM receivers (ESM)
- gamma ray detectors
Balanced objects will get a multidimensional sensor signature, based on their thermal housekeeping, power subsystem, thruster activity and active sensors.
Weapon systems
Ships can mount the following weapon systems types:
- external missiles (just like todays fighters external stores)
- external missile tubes (similar to a bazooka, can be jettisonned when no longer needed)
- internal missile tubes (a large bank of missiles, can't be reloaded except with a EVA)
- internal missile launcher (like the external missile launcher, but can be reloaded using automatic loading systems)
- ballistic weapons (launch usually unguided projectiles, but guided projectiles are possible)
- rail guns
- gauss (coil) guns / mass driver
- recoilless guns
- beam weapons
- Laser
- particle accelerators
Mines are considered a type of missile or projectile and are usually laid from either missile tubes or special mine racks.
There are also defensive systems: - Chaff launchers (create big smoke screens against visual detection and doppler measurements) - Jammer bouys (jam communications and primitive radar observations)
Passive protection
All ships use a multilayer protection, with the dimensions and number of layers depending on the object type: - weapons (projectiles, missiles) use a two layer protection, with a hardened shell below a thermal protection layer. - small craft use a three layer protection (from out to the inside): bumper shield, hardened shell and a inner shrapnel protection layer. - capital craft use a five layer protection: bumper shield, outer hardened shell, ceramic heat resistant foam (like aerogel), inner hardened shell, shrapnel protection layer.
Small craft and capital craft can detect impacts and their estimated damage by measuring plasma between bumper and main armor.
Capital craft can also measure the damage on the outside hardened shell by measuring resistance and capacity between sensor spots.
Subsystems usually use only single layer or two layer protection, though for critical components, a four layer armor like on capital ships (without the bumper) might be used. Its not possible to armor a HQT drive.
Damage model
The collision between objects (ships or projectiles) or beams always causes damage (even docking can cause damage, if it happens in a hostile way).
damage is separated into two different effects: - thermal/radiation damage - mechanic damage
Thermal damage heats, melts or vaporizes the target part. Mechanic damage are impacts and the related damages (including local thermal damage resoluting from impact energy). The thermal damage is always applied before the mechanic damage is applied. For calculating the mechanic damage of this shot, the thermal damage of this shot gets already applied. That does affect other shots until the next timestep.
For calculating thermal damage, two effects are calculated: Local damage and global damage. Local damage is directly influenced by the shot, and takes all energy at first. If the energy is enough for directly vaporizing the surface material, but does not burn through the armor layer, the thermal damage pass also creates a mechanic damage phase. If the damage is already enough to directly burn through the armor layer in this timestep, the remaining thermal and the mechanic damage (if any) are directed to the next layer of armor.
Each layer of armor has a scalar coverage value, which describes its coverage. 1.0 means, the armor is complete and undamaged, 0.0 means, no protecting armor exists. A layer also has an abstract thickness value which describes how much kinetic energy this layer takes from the shot.
When all layers of a armor are penetrated, the damage travels further - in a straight line for beams, the rest follows ballistic flight.
If the armor protected a subsystem, the subsystem gets damaged. If the armor was the representation of the ships skeleton, the structure got damaged, weakening it. The magnitude of the loss of integrity depends on the global damage on it (thermal + mechanic). If still damage energy is left, the damage has to penetrate the protecting armor again (except hull and structure parts), before it is allowed to travel further.
Its important to note, that all changes on the physical properties of a ship take place at the end of the timestep - not during it.
On large capital craft, its possible to implement the damage model of the hull in multiple segments, for better resolution.
Gameplay
The the player loads a scenario and enters the simulation mode. When multiplayer mode is desired, the first minutes of a battle get used as lobby phase, buts thats up to the involved players. Its not possible to respawn a vessel. Direct switching of ships by a player can be locked by the game engine. The rule is: If one player does not allow switching of ships for himself, all others are also not allowing it (all must agree to it).
Each ship has its own set of goals, but victory conditions happen on multiple levels: Own goals, squadron goals, fleet goals and strategical goals. Ownly the flag ship of a fleet can have fleet goals. Only the flag ship of a fraction can have strategical goals. Its not neccessary to define all levels of goals. There can even by no goals, which i call the melee mode - you don't even need to survive it.
For simplicity, time warp is limited to 1.0 or less. As the strategic drive system would allow a 2 hour or less transfer to the moon, thats not too important. If we implement moving to parallel space, its even possible to reach mars in 2.5 hours (34 days other wise). I think thats fast enough for us.
Weapons are rarely fired by the player. Instead, the player coordinates fire by assigning target priorities and commanding readiness levels for the guns. The weapons will get aimed at the target of the highest priority which passes the firing arc of a weapon. Only silver bullets like cruise missiles and large anti-ship missiles will be fired on command of the player.
References
- Atomic Rocket[3]
- Heim theory
- HPCC GmbH publications [4], especially: