The comrades from the People's Shipyard at Deimos present the LAC of Blessed Acceleration:
PowerThe LAC is supplied with 744 kW of electrical power, from a trio of 1 tonne strontium-90 RTGs, which operate at 56.1% efficiency and reject heat at 370 K. It was determined in initial design meetings that the most severe constraint for this ship would be the power budget, due to the unavailability of atomic fission reactors. Therefore, as with all ship systems, where it was possible to spend mass or less-than-ridiculous amounts of money to gain efficiency, this was done.
Heat is rejected through slightly-armored calcium radiators. Unarmored lithium radiators were specified initially, but these were found to be too easily shot off or boiled away by high yield atomic bombs, such as are carried by the Devastator missile. Also calcium looks cooler (even though the realism of that color is questionable). Like all radiators on the ship, they are quadruple redundant.
The design team considered using a water ice or ammonia heatsink to allow the radiators to be battened down during combat. This would allow a substantial reduction in radiator mass and considerably improve survivability (even with the armor and 4-redudance, the radiators are the weakest link on the ship). However, no ships have been built with this feature before, and it was thought imprudent to start experimenting with core ship systems during wartime.
Propulsion
Seven 4.5 km/s hydrolox engines accelerate the ship at slightly over 1 g. Hydrolox was chosen because it offers the best exhaust velocity of the non-fluorine fuel chemistries, and propellant density is better than methalox (according to the chart in the standards thread). Due to the embargo on boron imports and the recent sabotage of our bulk diamond manufacturing station, the engine thrust chambers are made of amorphous carbon.
Armor
The original armor plan called for 4 m of graphite aerogel, with an amorphous carbon backstop and spider silk spall liner. However, simulator testing revealed that, if a gun turret were destroyed, the resulting hole in the armor could permit bullets to enter the hull at highly oblique angles, and make their way through the backstop (which, honestly, can barely stop a stray fart), and into the crew compartment.
Therefore, the graphogel armor was split into two layers of 2 m, each topped with 1 cm of lithium. With this design change, if a turret is destroyed, bullets that don't come in nearly perpendicular to the hull will strike the second graphogel layer. And the only thing directly under the gun turrets is the nose hydrogen tank, which is much less mission-critical than the crew compartment. Fortuitously, the double-stuffed whipple structure also proved somewhat more effective at stopping projectiles than the graphogel alone.
A 500 micron lithium layer was placed behind the armor, in order to detect penetrations with the armor status overlay (anything that damaged 500 um of lithium almost certainly went through it).
Gun turrets are armored with 10 cm of amorphous carbon. This is reduced to 7 cm of amorphous carbon on the counterlaser turrets, for faster traverse. Main laser turrets have a perfunctory 200 microns of nitrile rubber. Due to their large size, heavier armor would balloon cost, mass, and most importantly, traverse power requirement. To deal with the hole left in the armor when the main lasers are inevitably shot off, they are placed around a spacer at the rear of the fuselage, just ahead of the engines, which are sparsely placed and multiply redundant.
Armament
The primary weapon system is a ring of 10 medium velocity machine guns, firing a 42 g projectile at 2.4 km/s. This weight is a homage to a widely renowned caliber from Earth's history, the ".50 BMG", and has proven very effective against common USTA armor schemes in testing. Our ship's guns, freed from the constraint of operation within an atmosphere, use a considerably larger diameter barrel and fire their projectiles at considerably greater velocity than the original. The rate of fire of each gun is 1800 rounds per minute.
In order to strike fear into the hearts of the enemy and sow chaos in battle, the primary weapon system is supplemented by a pair of large-bore cannons, which fire a shell containing a 1 kt plutonium bomb augmented with a 1 kg osmium plate. The plate is intended to penetrate the heaviest of armor when propelled by the nuclear blast, although this effect has not been tested. RFP Intelligence has informed us that the radar signal from the proximity fuze will cause the USTA's point-defense software to treat the shell as a very high priority target. This information has proven accurate in a few engagements with USTA vessels, where the atomic cannons were used to great effect.
For defense against drone attacks, the LAC of Blessed Acceleration also mounts four high efficiency (6.14%) 150 kW lasers, feeding four 2 1/3 meter radius turreted mirror. These lasers can bring 10.1 MW/m to bear at 100 km. In case the enemy fields lasers of their own, the LAC has a 100 kW counterlaser, feeding ten 5 cm radius mirrors mounted in fast-traverse turrets. Laser generators are mounted separately from the turrets, which allows them to be placed in otherwise unused space in the nose of the vessel.
Unfortunately, mere days before the LAC was scheduled to go into volume production, an internal audit revealed that the chief laser engineer had foisted the task of designing the lasers off onto her apprentice, who had specified diamond arc lamp envelopes. The chief engineer subsequently discovered a number of poorly encrypted emails in the apprentice's inbox, which proved he had been in the pay of the USTA for months. If this vile sabotage had not been discovered, hundreds of tonnes of precious diamond would have been diverted from front-line vessels. The lasers were quickly redesigned to use fused quartz arc lamps, which reduced their efficiency. That is, if we are to believe the saboteur's claim of 8.44% with the diamond envelopes.
The war department will be pleased to know that the traitorous apprentice has been transported to the Phobos penal colony.
Special FacilitiesFor defense against missiles which are too heavily armored or too numerous to be shot down with the main lasers, the LAC carries a number of 60-second flares. The otherwise very constraining RTG power budget was actually quite beneficial here, because it allowed the use of very small 10 MW flares.
In the unfortunate eventuality that that the enemy manages to kill or incapacitate the ship's human crew, the LAC of Blessed Acceleration is equipped with a small AI combat unit which will allow the vessel to avenge it's own crew, autonomously or under the direction of other ships in the same fleet. This capability was found useful in simulation with early design iterations of the ship, but has not been necessary in the field.
And of course, as specified, the LAC of Blessed Acceleration has spare bunks for a complement of 30 marines.
DoctrineProspective captains of this vessel class are advised as follows:
1. Always orient the nose of the ship toward the enemy, or even better, toward the direction of incoming fire. Never order your helmsman to orient the ship "broadside". Unfortunately, training at the academy has been rather lax during the war, and he will likely not understand which side of the ship that is on a vessel of this configuration. He will deprive you of the use of half your weapons, and he may expose the flat sides of your radiators, or allow enemy fire to strike the armor normal to its surface. In that case, the effectiveness of the armor is not guaranteed. He may also use up your propellant very quickly, by continuously trying to keep the side of your ship pointed at the enemy, while at the same time accelerating perpendicular to the sight line to the enemy.
2. Because of the small electrical power budget afforded your ship, your weapons are mostly chemical, and their muzzle velocities are quite low. They are, however, exceedingly accurate. It will probably be necessary to override the targeting computer, both to open fire earlier and, in engagements with multiple enemy ships, to cycle the computer between targets. Unless your ship is closing with the enemy very quickly, you can probably dispense enough bullets to shred his hull before the first ones arrive.
3. If an enemy vessel is equipped with lasers, it is best to leave the lens caps on your main lasers until the counterlaser turrets have achieved laser superiority. The enemy's fire control software is, unfortunately, somewhat more sophisticated than ours, and will focus fire on vulnerable lasers automatically. Yours, however, will not, so you should order your gunners to do so manually.
4. If the enemy launches missiles against you, it is suggested that you attempt to destroy them with the main lasers. If the missiles come within 60 seconds of intercept, it is imperative that you launch a flare immediately. Flares are much cheaper than lives, and your ship carries plenty of flares for any engagement. If you suspect that the missiles may be carrying high-yield warheads, you should keep attempting to lase them until about 10 s prior to intercept, then retract the radiators and hope for the best. Your ship is armored against nuke flash, but the radiators are comparatively delicate. Don't worry too much about overheating the RTGs. They are designed to operate significantly below the melting point of the fuel pellet, so you have about a minute and a half to get the radiators back out.
5. Drones can be easily dispatched by targeting their weapons with your main lasers, but after doing so you should order your helmsman to thrust a little, in order to get out of the way of any bullets they may have fired before their demise.
6. Do
try to dodge incoming fire. You've got lots of acceleration.
7. If you find yourself heavily outgunned, it may be useful to open up with the atomic cannons at extreme range. The enemy may become preoccupied with the incoming shells, and a lucky hit can take out their more dangerous weapons before they start shooting.
8. If, on the other hand, you find yourself facing a less threatening opponent, the main lasers work quite well for disabling a vessels engines, rendering it unable to evade bullets from the machine guns. Or if you wish to capture the enemy vessel mostly intact, you can use the threat of the machine guns to order the crew to stand down while you disable the rest of their weapons and board them. We envision that, when the war is over these LACs can be re-purposed for anti-smuggling and other police operations.
ScoringThis ship, with proper piloting, is capable of completing all three difficulty levels on its own. Since it only requires one ship, instead of three, I count the extras as undamaged.
Level 1:
Target destroyed: 1
All LACs survived with Δv: 3
All crew modules survived: 6
Total: 10
Level 2:
Target destroyed: 1
All LACs survived with Δv: 3
All crew modules survived: 6
Total: 10
Level 3:
Target destroyed: 1
All LACs survived with Δv: 3
All crew modules survived: 6
Additional friendly ships (-2): 8 =P
Total: 18
Grand Total: 38
The crew of the RSF Plasma Wake observe the icy remains of Admiral Voitenko's 1/2 Gc fleet:
This is what I was doing with detached laser turrets. The counterlaser system adds
people to the crew manifest.