Q: Does the voice file have any copyright issues?
A: I am not a lawyer, so I do not know. But since I do not sell this as a commercial mod, I guess it is okay. If you are the copyright owner and feel this is an issue, please contact me.

Q: Why use "Strategic launch detected" voice from Supreme Commander for the launch alert? Why not use voice from XXX game?
A: First of all, I like the game. Second, I like the voice. Third, the words are perfectly fitting with this mod, for strategy missiles.
Starcraft voices have been considered also. They are another 3 (one from each race) classic voices that instantly pops up in my mind. Sadly, they said "Nuclear launch detected", while I also have napalm and poison variants.
Without this reason, I am actually a bit more in favour (about 6-4) of Starcraft voices, especially the human race one. But due to the wording, Supreme Commander voice is definitely more fitting to this mod.

Q: Why strategy missiles can only be fired from vehicles? Why can't I fire them by hand/turret/artillery?
A: These superweapons are definitely OP in firepower. They have to be restricted in both game balancing concerns and realism.
First of all, it should not be fired by hand weapon (e.g., portable rocket launcher). Characters in late-game power armors with 6+ exoskeletons is super fast. There will be totally impossible for human defenders to avoid this kind of attacks. Furthermore, a MRV/MIRV missile weighs like 100 tons. Who can carry and fire that in hand???
Secondly, it should allow manual control on where to target. "Automatic" firing MRV missiles by turrets have totally no sense! So firing in form of ordinary turrets have also be ruled out.
So now it is quickly down to two options: vehicle and artillery. Artillery is actually an attractive way to do so. I wish to make a different artillery type turret that uses only the strategic missiles as ammo. However, artillery remote seems to be somehow hard-coded in the firing mechanism, and cannot distinguish what type of turret and/or ammo I am using. (Otherwise, I would have also done that to Schall Artillery.) Ideally, there would be another remote item for firing strategic missiles only. But it is not possible for the moment, at least not without heavy scripting.
Firing from vehicles (heavy rocket artillery) have all the advantages. It is realistic (in form of TEL, see below FAQ). It allows total manual control. And it allows the defender (human in PvP game) still a chance to destroy this vehicle before firing.

Q: Why use the warhead parts? Why not just directly craft the missiles in one-step?
A: A MIRV missile is a large object. It is usually assembled from different parts, instead of made from raw materials directly. Just like the vanilla space rocket, assembled from different parts is the more realistic way to do. (A MIRV missile is a space rocket, after all.) See the below FAQ for the warhead part.

Q: I like the warhead parts recipe systems. So why not apply it also to the vanilla atomic bombs, and Schall Tank Platoon napalm bombs and poison bombs?
A: True, I wanted to apply it too when making this mod. But then I looked into WWII-era atomic bombs (Little Boy, Fat Man) and cold-war MIRV missiles... Their structures are actually quite different. The warheads in MIRV missiles are practically changable. They can be refitted with more advanced type, as well as adjusting the number of warheads. (Look for those nuclear weapons reduction treaties and the behinding stories.) Simply to say, it can be quite flexible to "install" different warheads to a MIRV missile.
In contrast, an atomic bomb with a single "warhead" is designed to be quite compact. It is NOT like making a bomb casing, then can fit various types of warhead into it. The bomb casing has to be specifically designed for the type of "warhead" to be packed.
Therefore, I feel that the vanilla atomic bombs, other bombs, as well as atomic land mines (from Schall Land Mine) are unlikely to take advantage of the warhead systems, in terms of realism.

Q: Why use the name "MRV missile" on these strategic missiles? I have only heard of MIRV missile...
A: MIRV is the much more familiar term to public, true. But I have to first ask what the term means. The full name is "multiple independently targetable reentry vehicle". The "I" stands for independently, meaning each warhead can have independent targets (assumably cities). So in theory, a MIRV missile with 6 warheads can target 6 different cities.
However, in Factorio game sense, it is not feasible to have independent far-away targets with a single missile. Too OP in terms of game balancing. (Yup, real-world MIRV are truly terrifying...) The game also does not allow sub-munition to smartly target locations for maximal destruction, so the in-game missile does not qualify as MIRV.
The lesser variant "multiple reentry vehicle" (MRV) missile, carries several warheads which are dispersed but not individually aimed. This is less well-known, but is the much more exact description on how this in-game missile works.
Improved warhead designs allow warheads of the same size giving more yield (stronger firepower). While one warhead is enough to destroy most part of a city, it would be waste of firepower to target the same city. This is the reason why MIRV is much more useful (thus more well-known) than MRV in the real-world.

Q: Why use the name "Heavy rocket artillery" on the missile vehicle?
A: Right, the formal military classification of this vehicle should either be "transporter erector launcher" or "transporter launcher".
A "transporter erector launcher" (TEL) can transport one or more missiles, erect it (raised vertically into firing position), and launch it. This is the most common type known to the media and public, as the symbol of mobile nuclear warfare. Many well-known missiles can be carried by TEL, from Scuds to the Topol-M to the Chinese DF-15 and DF-21D to almost all North Korean missiles. However, Factorio does not support such turret erection preparation animation. Therefore, this name will not match too well. (Not to say, I have no proper spritesheets for the vehicle at all. I can only use vanilla tank spritesheets tinted to distinguish different classes.)
A "transporter launcher" (TL) is quite similar to TEL, except it is already locked in firing position (angle). This term is less common, but definitely much more fitting to Factorio animation system (if any proper graphics is to be applied). But the big problem is that players not having military background in strategic warfare will get this military jargon at all. By applying this name "transporter launcher" to a vehicle, how many players will have the impression it is of "civilian" use because of the word "transporter"? How many of them can immediately know that this is the vehicle for firing all those world-devastating strategic missiles?
So instead of the above very accurate terms, I am using the broader term. "Rocket artillery" is much more well-known. Players immediately will know this is for firing rockets (or missiles, the two terms are used interchangably in English) to attack. Also the base mod Schall Tank Platoon is already using this term, so players will have no problem with that. "Heavy" is the generic term for describing rockets/missiles are more heavy (thus more firepower). So a term more obviously to most players, isn't it?

Q: How does the (manual) missile interception work?
A: Just fire the missile interception shell on the missile you want to intercept. Missiles and other non-friendly projectiles with range (currently 4 m, or equivalent 4 tiles) will be affected. There will be a flying text indicated how many projectiles got succesfully intercepted.

Q: Does the interception works on non-missile projectiles? For examples, rockets, cannon shells, artillery shells...
A: Yes, by default, the interception works on all projectiles including the above-stated ones, and also the "stream" type including spitter acid and flamethrower flame. You may choose to exclude "stream" and/or "artillery-projectile" in option "Interceptable objects" under mod option settings.

Technical Details

Heavy Rocket Artillery

A series of dedicted vehicles to launch the strategic missiles, a set of superweapons introduced by this mod. (For why cannot be launched by other means, please see the above FAQ section.)

The heavy rocket artillery comes with four variants:

Higher tier heavy rocket artilleries have strategic missile launchers of longer range. Apart from that, they also benefit from higher health, higher damage resistances, stronger engines, and larger equipment grids (Upgrades similar to other tanks and vehicles from the above-mentioned mods), allowing better survivability.

Strategic Missile

Strategic missiles introduced by this mod are equivalent to MRV missiles in the real-world. (Please read above FAQ section about this term.)
Each of them are carrying eight warheads, which is just similar to their respective vanilla Atomic bomb or Schall Tank Platoon bombs. For example, firing ONE atomic MRV missile is equivalent to firing EIGHT vanilla atomic bombs scattered.

This mod provides the following strategic missiles:

• napalm MRV missile
• poison MRV missile
• atomic MRV missile
• plutonium MRV missile

Heavy rocket artilleries are REQUIRED to launch these superweapons.

The ordinary rocket artilleries CANNOT launch them.

Missile Interception

Missiles and any other projectiles are NOT destructible in vanilla gampeplay or any mods (currently). This mod, however, provides a special means, so that you have a chance to destroy these projectiles before the damage is dealt!
This feature is essential for a high-tech PvP gameplay, to prevent players of the enemy team from destroying your base with just an "insignificant" missile! This can still be fun to stop spitter acid in a PvE game though.

Missile Interception Shell

• Fly at hypersonic speed and release electromagnetic pulses to disable missiles (or other projectiles).
• Shot from: Portable missile interception cannon.
• Target: Position
• Form: Ultra-fast cannon shell.
• Collision: No
• Damage type: Electric
• Shot damage: 5
• Area of Effect: 4
• Effect: Projectile interception
• Use: Just fire the missile interception shell on the missile you want to intercept. Missiles and other non-friendly projectiles with range (currently 4 m, or equivalent 4 tiles) will be affected. There will be a flying text indicated how many projectiles got succesfully intercepted.
• Tips: Aim a bit forward of where you expect the missile. The shell is super fast, but still take some time to arrive.

Portable Missile Interception Cannon

• Capable of intercepting projectiles.
• Range: 24
• Fire rate: 0.5 /s
• Upgrade techs: None
• Use: Intercept non-friendly projectiles around the target position.
• Tips: This is a portable version of the giant cannon. Shells are fired at hypersonic speed for a better chance to intercept the missiles. Due to the "lightweight" (compared to the full size cannon) requirement in order to be carryable by infantry, cooling system is cut down that leads to a considerable drop in rate of fire.

Missile Interception Autocannon

The full size autocannon mounted on missile defence tanks. Much bulkier and heavier than the portable cannon variant, but the enormous cooling system and motors allow the multi gun barrels to work at sustained high speed, as the more reliable choice of missile defence. Also the uplinks allow connections to various tracking systems, giving automatic missile interception (without the need of player manual control).
This is a planned feature, so not yet available. I have to see how much the players wanted this feature first.

Full List of New (or Changed) Items

Tanks / Vehicles

• 4 auxiliary half-track:
  • Heavy rocket artillery
  • Heavy rocket artillery MK1
  • Heavy rocket artillery MK2
  • Heavy rocket artillery MK3

Guns

• 4 strategic missile:
  • Strategic missile launcher
  • Strategic missile launcher MK1
  • Strategic missile launcher MK2
  • Strategic missile launcher MK3
• 1 missile interception:
  • Portable missile interception cannon

Intermediate Parts

• 5 ammo-related:
  • Strategic missile - Empty
  • Napalm Warhead
  • Poison Warhead
  • Atomic Warhead
  • Plutonium Warhead

Ammo

• 4 strategic missile:
  • Napalm MRV missile
  • Poison MRV missile
  • Atomic MRV missile
  • Plutonium MRV missile
• 1 missile interception:
  • Missile interception shell

Technologies

• 5 strategic-missile-related:
  • Strategic missile 0
  • Strategic missile 1
  • Strategic missile 2
  • Strategic missile 3
  • Plutonium MRV missile
• 1 missile-interception-related:
  • Missile interception 0