Zentreadi Fleet in Force of Arms and post-episode

[ShadowLogan]

In the Robotech Episode "Force of Arms" in the Macross Saga the Zentreadi marshal their Grand Fleet, which consisted of 4,500,000 warships PLUS Dolza's main base to attack the Earth, the SDF-1, and Breetai's 1,000,000 warships (plus Khyron and Azonia's fleets, and any remnants of Breetai's original fleet). So, in total there where present approximately 5,500,000 Zentreadi Warships plus Dolza's Base present in Earth orbit in that episode.

We also know from a later episode that the Masters registered the destruction of over 4 Million Robotech ships (due to Protoculture discharge). Based on show dialogue that means ~72% of the ships were destroyed, though the dialogue IMHO implies the needle was pegged so the actual loss could be more (and it should be noted that I suspect each type of vessel is likely going to register differently, a Scout Ship's PC discharge is probably not going to be the same as say a Flagship).

What follows here will be 2 main Parts with sub parts, implications of all those ships being present (pre-destruction), and what the Earth could have done with those ships.

Part 1: Implications
Now AFAIK RT doesn't have an actual break down in terms of ship types, and the OSM numbers are going to be a best guess since Breetai's fleet in RT is 10x what it was in the OSM IINM, and there is no guarantee the resulting breakdown scales the same way. As such I am using the available information (RT.com) on the Flagship, Command Ship (combined, no subsections), Carrier, Destroyer, and Scout to create a generic "AVERAGE" Zentreadi vessel in terms of dimensions (2504m x 592m x597m) and mass (9.205x10^10kg) for the following sub-parts, so unless otherwise stated directly this is the ship I am working with and not specific types (it also allows one to avoid the unstated ships like the type Khryon used in Ep36 to destroy the SDF-1). Dolza's Fortress will also be considered individually.

Sub Part 1A: Tidal Forces
If the Grand Fleet Ships (minus Dolza's Base Ship) and Breetai's Fleet (total 5.5million ships) could bunch up to act as a single massive object orbiting the Earth there isn't a practical orbital altitude (I went down to 160km) where their gravitational force exerted between them and the Earth would match the Moon's (in current orbital average distance of 384,400km). Individually the ships aren't going to amount to much due to their mass, but as a hypothetical conglomeration it is interesting. That isn't to say the gravitational impact of all those ships couldn't be an issue, especially if they bunched up (which DOES NOT Happen), but it isn't going to be as much as...

Dolza's base ship on the other hand is massive at 0.16% the mass of the Moon. Where things get interesting is that at an Orbital Altitude of ~9,400km Dolza's Fortress exerts as much gravitational force on the Earth as the Moon does at its average distance from Earth. At 2,000km altitude it would exert ~3.5x more force, I didn't go any lower due to the size of the Fortress (though if it goes on its side...). So, Earth would experience Tidal forces of potentially destructive results (earthquakes, volcanos, ocean tides) given enough time that would be stronger than anything the Moon generates on Earth currently. So basically, weapon attacks aren't the only way the Zentreadi are going to inflict havoc on the planet depending on their altitude.

Side Note: Lawarence Krauss in his "Beyond Star Trek" Book (guy also wrote Physics of Star Trek, basically the same book only looking at other franchises like) when he considered the Mothership and the City-Saucers from Independence Day Movie points out things that the movie makers got wrong. The Mothership which had a mass of 1/4 the Moon and took up GEO spot, if I did my calculations correctly would be ~6x more powerful in terms of gravitational force than Dolza's ship at 2,000km and should have unleashed a lot of devastation.

Sub Part 1B: Area Coverage
Assuming each of the 5.5million ships (none of this considers Dolza's Fortress) in question is treated as an oval/egg shape for simplicity, this means in actual practice some ships might actually be under/overrepresented in terms of calculated area, and the ships present the largest 2-D plane toward the Earth, how much of an imaginary sphere's surface area would those ships block out from the sky as viewed from Earth:
-@35,786km altitude above the Earth: ~0.04% (a separate ~0.00% for Dolza's Fortress).
-@2,000km altitude above the Earth: ~0.80% (a separate ~0.04% for Dolza's Fortress).
-@1,000km altitude above the Earth: ~1.03% (a separate ~0.05% for Dolza's Fortress).
-@675km altitude above the Earth: ~1.13% (a separate ~0.06% for Dolza's Fortress).
-@at Sea Level/Earth's Surface: ~1.38% (a separate ~0.07% for Dolza's Fortress).

For comparison Earth's Moon at its average distance from Earth the Moon covers ~0.0005%, and at that distance the CZF would be a bit smaller than the Moon in terms of area covered. This means that the CZF would be a few thousand times larger than the Moon at those closer distances noted above. So, it seems unlikely the Zentreadi are going to block out the sky even noting the previous since they spread-out to envelope the planet, it's just in reality they aren't going to be blocking out the sky everywhere.

It should also be emphasized that is for the entire sphere, which is not going to be visible all together, so the actually coverage "locally" is going to be much more.

Sub Part 1C: Zentreadi Population @ Earth
Since we are creating an "Average" Zentreadi ship to use as a standin for mass and dimensions, barring official break down numbers of the CZF, if we take that to the crew size (using RT.com's Infopedia). We end up with an Average Crew size of 7,910 crew and troops, carrying that out to the 5.5million ships you'd have a population of 43,505,000,000 giant Zentreadi PLUS those on Dolza's Fortress, that is over 43.5 billion. Now it should be noted the primary driver of this number is the Flagship and Commandship, but they likely also make up the smallest portion of the known ship types. If we factor them out and just use the Destroyer, Carrier (Landing ship 1E), and Scout ship as the basis that lowers the average crew/troop size to 5,773 resulting in a population of 31,753,333,333 Zentreadi (31.7 Billion) not counting Dolza's Fortress. This might still skew things a bit on the high end going off the 1E RPG Zentreadi SB's breakdown of Khyron's fleet (1Cmd, 4 Destroyer, 4 Scout, 2 Landing/Carrier)

If we take the Masters assesment that 4million ships are destroyed and assumed 100% survivability of the crew/troops on the remaining ships... The human population on Earth would be outnumbered, and that is PRE-Rain of Death (and the smaller average is more people than currently on Earth in the real world in 2011's 7 billion humans). Now 100% survivability is probably unrealistic and the Masters actually state over 4million are destroyed (technically), but still, we are potentially looking at billions (pessimistically millions I would think) of Zentreadi survivors at Earth.

Part 2: Where did all the ships go?
We know some of them eventually made it to the surface of the Earth and made a crash (or controlled?) landing, we also know some ships remained in service with the Earth forces during the mid-to-late 2010s (FTS Comic, plus the RFS capture episode), and we know some were destroyed (Grand Cannon, Dolza's fortress exploding, ship-ship engagements, etc).

Where they went, we don't know, but it would seem to be reasonable that the remains of the fleet were moved out of their FoA Episode orbital position by 2029 (or at least the orbital planes used by the UEEF/UEDF/Tirolians in 2029-44), though there is no actual need to if their orbits are high enough. What follows is more suggestions on what those ships could be adapted for (outside of the usual restored ship in UEEF/UEDF service for human size crew).

Most are far future stuff for Earth, but for campaign purposes could provide ideas for settings or background in a variety of ways in Robotech (and even Macross 2) like the race that nearly caused the destruction of the Zentreadi (Exedore mentions them in passing dialogue, the Zentreadi numbers at the time might not be as great), or alternate timeline Earth's (visiting ala "Sliders" or native), or as said distant future stuff.

Sub Part 2A: Space Telescope
Theoretically you could turn any of the ship into a (ideally unmanned) Space Based Telescope/Observatory. Chop off an end (or remove the engines) or divide it into sections and make other internal structural changes would leave you with a Telescope with a light gathering area potentially at ~500meters in diameter, for the record the largest current optical telescope is ~10m, to make one ~500m in diameter is likely going to require manufacture in space or sectioned mirrors (which can and has been done). Other types of Telescopes should also be possible that look at other electromagnetic frequencies besides optical light (UV, IR, X-Ray, Gamma, etc). Other alterations to the ship might also be necessary. Then again you could just set them up in a hangar deck (or airlock) and open the hangar/airlock and you should easily be able to go beyond the 10m diameter size (especially if to save power you cut off artificial gravity), you won't get the 500m diameter, likely in a more reasonable 20-100m diameter (size of known craft to depart the Flagship).

Now why do this? Well aside from the straight science aspect that I would think is still going on, the telescopes could have more practical roles for the military as they could be used in like Asteroid/Comet detection (don't want any to hit Earth) or spot potential De-Fold operations w/n the solar system (big flash of light on De-Fold, though don't forget to account for light-travel time).

Sub Part 2B: O'Niel Cylinder/Space Habitat
An O'Niel Cylinder is basically an artificial world constructed in space, think Gundam Space Colonies. You'd hollow out the interior of a Zentreadi ship (Destroyer-class or larger, sorry Scout is to small) to form a cylindrical world that would be rotated internally, you'd probably also have areas at the ends (or even w/n the sides for some of the odd shaped ships), this would allow creation of "artificial gravity". This would provide approx. 4.5km^2 of surface area using the AVERAGE Zentreadi ship, though in practice it will be less. It should be noted you could avoid the extensive interior remodeling called for with O'Niel Cylinder and just repurpose the existing decks which could theoretically net you more area to work with (assuming each ship has an average deck height of 35m, and the decks are treated as generic ovals). Now O'Niel Cylinders are long, so to get a true one going is likely going to require connecting multiple ships end to end.

This might match up with the dialogue in NG episode #1 when a UEEF crewmember makes the off-cuff remark "we were all born out in deep space aboard a Robotech ship" (or close to it).

They can also work as Colony Ships (negating the need for the Angel-class, which might itself be retconned into Zentreadi origin as N-S like ships do appear in TMS), assuming they can be made flight worthy (even if only for a 1-way trip) to establish outposts elsewhere in the Solar System (no Fold Drive required) or extra-solar (Fold Drive required).

Granted this heading is basic derivative stuff that is likely obvious.

Sub Part 2C: Artificial Orbital Ring
If you take surviving ships and connect them length wise or at their Widest Points via existing docking systems or purpose built scaffolding (we do have tons of debris to salvage from) to form a giant ring around a Planetary body like Earth, Mars, Venus, or Mercury to act as a space-based habitat with a lot of available space. Alternatively, you could break them down to provide raw materials to do it the more "classic way". Some of the various moons in the Solar System would also work, though I think their location, and such might complicate things. Such a ring could be used as part of a skyhook system or space elevator-type system, both of which are systems that aim to reduce launch costs (but require costly infrastructure to setup). Repurposing the ships in this way, even without power might allow the doctrine of quaker-guns given the numerous beam cannons you would end up with that likely would be unable to fire due to lack of power (missile launchers on the other hand likely won't require the same level of power).

If such a Ring were constructed at Earth out of the generic AVERAGE Zentreadi ship it would require:
-406,772 ships by width or 118,398 ships by length at altitude of 35,786km
-80,827 ships by width or 23,526 ships by length at altitude of 2,000km

These numbers would also work for Venus (it has a similar diameter to Earth). Mars and Mercury would require less ships for similar altitudes as they have smaller diameters than Earth. Various moons in the solar system (including Earth's) could also work. Based on the animation we don't see anything like this in play at Earth (or "Mars"), but one might also argue the thickness of one of these rings might be to small to notice easily as at best we are only talking a few kilometers thick, factor in the dark coloration of the hulls and it could be there, and we just would not notice it without specific circumstances.

I also don't think this would be built/finished in the 20years between TMS and TRM and is presented here as a far future possibility (I could be wrong), assuming the ships were moved to some type of deep space boneyard for later use. And the number of ships required might seem large, but 1% of 5.5 million is 55,000 ships so we aren't talking about a needing a significant portion to survive intact (if even out of fuel) and has been noted previously in dialogue at least 72% are said to have been destroyed. TPTB also seem to favor the UEEF/UEDF using salvaged Zentreadi systems (like Fold Drives, though none of their BFGs) for some time.

Sub Part 2D: Venus Terraforming
Even at full strength 5.5million Zentreadi Ships won't have the coverage area to block enough sunlight as suggested for some proposals for Terraforming Venus (using a sunshade at its Venus-Sun L1 point). That said there are a few ways to use the ships for this process:
-if you could slice a ship along its long axis and get 20 "slices" per ship you do it, however those 20 slices assume you have all 5.5million ships to use which means you will need to get a lot more
-use the ships as raw materials to provide the final products: a sunshade(s) and ballast. Someone else calculated that an aluminum shade made 0.1 micron thick with x2 the diameter of Venus would have a mass of 124 million tones with several billion in ballast. In terms of mass, we'd be talking several hundred ships to meet this (using Destroyer or larger vessels), though this ignores material composition meaning you'd need either more ships or supplement the material supply from elsewhere.

This would take about hundreds of years to cool the planet once completed. So, if this was something Earth did it would be a long-term project (and being more extensive than just the shade). There will need to be several other things done to successfully terraform Venus like altering its rotation to something more normal, import water (either as water or just plain hydrogen) and possibly other elements necessary for life, create an artificial magnetosphere. This also assumes that Zentreadi don't have any duce-ex-machina terraforming technology that could be adapted that could do the job faster.

I only bring this up because it might explain Scott's "vast as Venus" comment about an Earth wasteland in NG#1. Now if a Shade could cool Venus (and altered the atmospheric pressure) enough for Scott to visit the surface between 2013-"2042" I don't know, but it seems unlikely.

Sub Part 2E: Solar Power Collector Satellites
The ships, even in their depleted state could be used as the skeletal structure for solar energy collectors and equipment to beam the energy back to Earth. To replace a real-world power plant would require larger ships, but in theory you could attach the ships together to form a bigger unit. The ships themselves can also be used as depots contained repair crews, parts, etc.

Sub Part 2F: Cloud Cities
I considered the idea of using the ships as floating artificial "islands" on Venus. These results are really iffy because I treated the various types as simplified cylinders or rectangular cubes (both actually) and am not taking into consideration the "lifting" power of the "earth-like atmosphere" for the crew or any other payload for mass. As such the results here should be treated with a few grains of salt unless someone else wants to do a deeper dive.

What I found was that (in order of low density to high) a Zentreadi Re-Entry Pod, Destroyer, Command Ship-Bow Section, Scout, and Command Ship (combined, but just barely) are less dense than the atmospheric density of Venus at the surface. I'll also add that the UEDF/UEEF Tokagawa class is comparable the Re-Entry Pod. Now at 50km altitude the pressure is similar to Earth at sea level, and they will all be to dense to float at this altitude, at least not without some type of mass reduction program to make them lighter (a Tok and Re-Entry Pod need to be reduced down to ~1/6th their listed mass, Destroyer/Bow-Section ~1/30) and/or some means of passive assistance, though "as is" they would float somewhere between these two values. Nothing prevents them from using an active system (like their gravity control system), but this will require large amounts of power (ie protoculture) to keep running.

[taalismn]

You have entirely too much time on your hands.
I appreciate that.