Data File Updated: Thursday, October 02, 2014

The Terran Colonial Authority

In 2160 CE, Human society is composed of six independent worlds (of which Earth is one), and each world is divided into many independent nations, so there's no one centralized government representing all of Humanity. The next best thing is the Terran Colonial Authority (TCA), a treaty organization which oversees interstellar issues, manages the colonial process, and provides for the common defense of Humanity through the military (Colonial Fleet) and exploration (Scout Corps) arms. The TCA is run by a council of delegates from the six worlds, but in practice, its policies tend to be dominated by Earth's interests. Which is not terribly unfair, considering that the vast majority of Humanity still reside on Earth.

The TCA was founded in 2107 to replace the hodgepodge of competing colonial organizations that had handled the earlier colonizations of the Alpha Centauri system, in the hope of preventing juridisctional disputes during the scramble to colonize Tau Ceti II (Aldea). The Scout Corps was formed out of the best of the existing exploratory teams of that early period. The military Colonial Fleet was authorized in 2115 to prevent armed conflict between the competing interests on Aldea.

The TCA is somewhere in between NATO and the US Federal Government in the scope of its powers, run by a delegation of member states and a federal bureaucracy. No doubt the large Earth nations will require some special concessions to sit down at the same table with tiny colonial nations, perhaps in the form of veto power or something like the bicameral system of the US Senate and Congress, but the details aren't terribly important in story terms.

An important thing to consider when thinking about the colonies is that each colony world is not going to be a monolithic entity; each world may have dozens of independent colonies, set up under different charters. Some will be on friendly terms and may cooperate to form a planetwide meta-government, and some may be on unfriendly or even hostile terms with each other. At the current time, there are no major hostilities between the various nation-states, and those that are unfriendly have temporarily set aside their disagreements in view of the greater mutual threat.

When a colony is first chartered, it is probably not yet recognized as an independent nation, and will probably need a sponsor, which will be an existing (usually Earth) nation-state, a corporation, or occasionally the TCA itself. The goals that the colony needs to reach will be explicitly specified in the charter. A colony that has not yet earned statehood will probably have a TCA governor, who might be appointed or elected, but who probably has to be approved by the TCA.

Is there a set of standards that these governments must meet in order to be recognized? Sort of like the standards that NATO imposes (civilian control of the military, etc) on prospective members?

Member nations, in particular the chartered colonies, will be required to adhere to a sort of bill of rights as a condition of membership, but otherwise TCA members remain independent, sovereign nation-states, and may maintain their own planetside militaries – only space-based forces, especially those with FTL capability, are regulated by the TCA. Although the TCA does have a Colonial Marines service, their main instrument of enforcement is the threat of denying access to interstellar shipping, which is critical to all of the colonies.

I would like to think that autocracy and systematic oppression will be out of style by 2160; it's bad for business. Of course, the millennia-old conflicts between the social and ethnic groups on Earth will still exist (and some of these will no doubt be carried to the stars), but I think the most oppressive of Earth governments will have been cleaned out by then. In 2160 anybody with access to the appropriate materials can make a weapon of mass destruction... so a nation that has internal strife is a clear and present danger to the world at large, and the other nations can't sit by and wait for something to go wrong.

The Worlds of Humanity

The "Six Worlds of Humanity" mentioned by Alex are Earth, Mars, Alpha ("First"), Proxima ("Near"), Aldea ("Village") and Esperanza ("Hope"). Humanity first began settlement of Mars around 2050, and developed the first working hyperspace jump drive in 2086. At the turn of the 22nd Century, Humanity began to establish extrasolar colonies in the Alpha Centauri and Tau Ceti star systems, and later at the 82 Eridani system. All four of the human-inhabited systems are yellow G-type stars.

Earth (Sol III)

99% of all of humanity still live on Earth. Though the population has increased along with technology, and some of the largest cities have grown into megalopolitan monstrosities, I think people today would have no trouble recognizing the Earth of 2160. Earth is still divided into about 200 nations-states, though many of these are joined in local alliances or federations. Earth is renowned for its extensive orbital infrastructure; the TCA Headquarters and the majority of humanity's ship production infrastructure is located in Earth orbit.

What is the current government of Earth? The United Nations? The TCA?

There is no united Earth government. The TCA's jurisdiction is limited to interstellar affairs. The United Nations may still exist, but it has no real legal authority or means to enforce its resolutions. The majority of Earth nations belong to local confederations similar to today's European Union or Russian Federation. These confederations in turn will be part of a treaty organization (which will functionally replace the UN) with authority to arbitrate over disputes, and this will be the closest thing Earth has to a planetary government.

Mars (Sol IV)

Mars was first colonized in pre-FTL days (around 2050), and has become a center of heavy industry, as carbon and greenhouse gas emissions that would be considered pollution on Earth are very welcome on Mars, to help thicken the sparse atmosphere. Mars is cold and arid, has a surface gravity of .38 G, and a very thin atmosphere, which still far too thin for humans to survive in without pressure suits. There is very little surface water, and dust storms are frequent. Mars has been the subject of early terraforming efforts, including solar mirrors to increase global temperature, and various introduced engineered species of algae to oxygenate the atmosphere. These efforts have begun to show benefit to the inhabitants, but will require hundreds more years before the planet becomes anything close to habitable by unprotected humans, and even then only in the lower altitudes. The major settlements are in the northern lowlands and the Hellas basin in the Southern Hemisphere, with smaller outposts in the Tharsis highlands and elsewhere. There are major facilities in orbit, including several shipyards and orbital habitats. The main campus of the TCA Space Academy is located in Hellas Planitia. Population of Mars is around 50 million, divided into numerous sovereign nations and colonies.

The largest Martian nation is Yinghuo (Mandarin: "Firefly"), which controls most of the northern lowlands and has its capital Yuchin in Chryse Planitia. Yinghuo began as a Chinese manufacturing colony, but it quickly grew in prosperity and power and gained independence in 2081, and became a major player in the second phase of extra-Solar colonization. Yinghuo has traditionally been aggressive in its dealings with other entities, involved in recurring conflicts with the Tharsis independents, and was a player in the dispute over early Aldea territorial rights that nearly led to armed conflict and spurred the formation of the TCA and the Colonial Fleet. 

The second largest Martian nation is the Ares International Corporation located in the Hellas basin, and is more metropolitan than the largely ethnic Chinese state of Yinghuo. AIC is also focused on manufacturing, but has additonally been conducting terraforming experiments in the low-altitude, confined territory of Hellas.

Alpha (Alpha Centauri A V)

Alpha was the first extra-solar colony, located around the A star of Alpha Centauri, a trinary system, and the nearest star system to Sol (at 4.3 light years). It is a cold, dry Mars-sized planet (.4 G surface gravity) with a very thin atmosphere. The colony was primarily a research installation until later colonization of more distant systems allowed for the development of more infrastructure to support transit to the outer colonies, with Alpha's smaller gravity well (compared with Proxima) making it the more attractive refueling stop for outbound starships. Population about 600,000, divided between several independent colonies. Alpha and Proxima are jointly admininstrated by a TCA governor located on Proxima.

Proxima (Alpha Centauri B III)

Proxima was the second extra-solar colony, also located in the Alpha Centauri system. It is Venus-sized, with a surface gravity of .9 G. It has an elongated orbit around the B star in the system; for most of its 15-year orbit, the planet is very cold and all the surface water is frozen; when the planet passes through perihelion, it warms up substantially and small temporary seas form, supporting primitive native microorganisms (which survive in geothermal vents during the cold periods). Human population around 18 million in numerous independent colonies, under the jurisdiction of the local TCA governor. Although Alpha is the less signficant of the two colony worlds, inhabitants of the Alpha Centauri system are often collectively referred to as "Alphans." (Note that "Proxima" the planet should not be confused with Proxima Centauri (a.k.a. Alpha Centauri C), the small red star which is the third component of the trinary system.

Aldea (Tau Ceti II)

Aldea is an Earth-sized planet (1.1 G surface gravity) in the Tau Ceti system, 11.9 light years from Sol. Aldea has a large amount of surface water (even more than Earth), and a dense but breathable atmosphere. Tau Ceti is an ancient Population II star more than twice the age of our Sun, so Aldea is very poor in heavy elements, but the ancient oceans are rich in Helium-3, a key fuel for second-generation fusion reactors. Aldea's metallic core is small but geologically active, due to the tidal stresses of its large moon, providing continuing heat in an ancient core that had long since exhausted most of its supply of radioactive elements. The small core and mantle support incredibly deep and very dense seas, upon which a few light and rocky continents float. Though native life on Aldea is considered primitive by Earth standards, it is much, much older. Some speculate that the scarcity of heavy elements has slowed or even arrested the evolutionary development of life into more advanced forms. Aldea has wet, stormy weather most of the year, driven by extreme tides. Human population about 125 million, making it the largest base of humanity outside of Earth.

The colonies in the Alpha Centauri system were set up primarily as research stations, but the valuable fuel sources on Aldea (and its more welcoming environment) made it a true target for both commercial development and large-scale habitation. This led to inevitable disputes between competing colonial interests. In particular, the Sol-Tau Ceti trade route became the object of a proxy conflict between interests on Aldea controlled by a group of multinational Earth corporations, and those controlled by Yinghuo, an influential Martian nation. In response to the increasing pressure exerted by Yinghuo, the other Aldean colonies joined together to form a collective. When both sides began arming their transports, escalation seemed inevitable, and the TCA charter was amended to allow for the formation of the Terran Colonial Fleet. Under the terms of the agreement, the Aldean Self-Defense Force surrendered its armed ships to the new Colonial Fleet, and all of the Aldean colonies (including the Yinghuo proxies) agreed to form a global federated government, which is a full member of the TCA and persists to the present as the only planetwide government in Human space.

Esperanza (82 Eridani VI)

Esperanza is the newest colony, and the farthest away from Earth (at 82 Eridani, 19.7 light years from Sol). Esperanza is arid but Earth-sized (.8 G surface gravity). Like Tau Ceti, 82 Eridani is an older Population II star with lower than normal metallicity, and Esperanza is comparatively metal-poor and lifeless. Esperanza is arid, cold, dark, and plagued by near-constant dust storms. The main benefit of the Esperanza system is its strategic location, 82 Eridani being the only G-type star along the route leading out of the relatively isolated bubble of Human space. Ambitious terraforming projects have begun on Esperanza, but are in their earliest stages. Population: 5 million, under the administration of a TCA governor.

Is there much colonization outside of these six worlds? In asteroid belts or Oort clouds or whatever?
There are outposts, mining camps and the like elsewhere in these systems (and perhaps in other systems as well), but these six are the permanent settlements.
And how much commerce is there between the various colonies?
A lot. The colonies are still heavily dependent on Earth and Mars for many supplies, especially finished goods, as well as immigrants, and there are a lot of raw materials traveling the return route from the colonies to Sol. There's enough commercial shipping for the TCA to need to build a fleet to keep it in line.

So we can assume that piracy is a very real threat? What about the behavior of the pirates? Are they likely to cripple a ship for its supplies, capture it and ransom the crew and/or ship?

The Terran Colonial Fleet exists to deter a number of potential threats to interstellar shipping: piracy, smuggling, hijacking, terrorism, and sabotage or blockade by rival merchants or nations. Since starships are often more valuable than the cargo they carry, both could be targets of potential pirates. A side-benefit of the Fleet is defense against potential alien hostiles, which is one reason there are some heavier ships (such as the heavy cruisers) which are not strictly necessary for patrol duties, and probably spend most of their time docked at base.

If someone did have black market goods where would they most likely be offloaded, aside from independent operators? Where are independents, i.e. pirates, fringe groups, exiled criminals, religious extremists, etc. most likely to settle?

Along with the high cost of operating a warship, the biggest obstacle to piracy is the lack of a base from which to refuel and a market for stolen goods. Starship fuel requires substantial infrastructure to refine and store. Few criminal organizations would have the resources to establish an outpost in deep space, and any such base would probably be quickly found and destroyed by the Fleet. So, criminals and smugglers have to be sneaky... a shady corporation, for example, might buy goods stolen from a rival and shelter the thieves.

Where are independents, i.e. pirates, fringe groups, exiled criminals, religious extremists, etc. most likely to settle?

All of the colony worlds are only marginally habitable, so any new settlement is going to be heavily dependent on supply from some outside entity (usually a colonial authority) until it can become self-sufficient. It's very difficult for a fringe group to establish a settlement without substantial financial backing. Also, in the age of mechanization, the need for unskilled labor is not very high, so forced labor would not be in great demand. In this early phase of colonization, passage offworld is very expensive; nations do not pay exorbitant sums to move criminals and malcontents to the stars where they must be supported at great expense. The vast majority of the colonists must either pay their own way offworld or have valuable skills to offer a corporate or government employer.

Overpopulation may provide motivation for people to move offworld to escape it, but this movement won't significantly reduce overpopulation on Earth, so it's not any kind of solution for overpopulation. If Earth nations choose to subsidize the movement of population to the colonies, it will be for other reasons.

In our Age of Sail colonial period, it was common for colonists to pay for transportation to the New World by agreeing to enter into limited terms of indentured servitude. While indentures will probably not be legal in this future, many colonists will probably still agree to contracts that require a certain number of years of employment in return for transport costs, which will come due if the worker decides to quit early. So there is the strong possibility of worker/employer conflict on that issue alone, as frontier conditions are likely to be harsh, and workers may be inclined to feel mistreated due to the fact that they can't really quit.

Rogue asteroids come to mind for their defensive and resource values, space stations, or planetary bodies, etc. How would colonial and naval authorities deal with this?

They'd move in and either take the base over, or simply destroy it if capture seemed too difficult.

Due to the inter-colony trade is there a significant number of independent merchants? How do independent merchants react to piracy, i.e. do they trade with the pirated goods, set up agreements to move through pirate space, etc.

Starships are very expensive to build and to operate. The majority of transport ships are owned by large corporations; some are operated by smaller companies, and a few are independently operated. Regardless of who owns the ship, all cargoes have to pass customs at local ports, so shippers have to be careful about where their cargoes come from; illegal cargoes must be carefully "laundered" to disguise their origins.

How did all of these groups react to the news of alien presence?

The opening of alien markets will definitely be good news for merchants... both legitimate and otherwise. The existence of a dozen or so alien markets that are not under the control of TCA regulations will no doubt be a boon to would-be pirates or smugglers. But this would be after the war is concluded, assuming that humanity survives. Currently, no one but a select few agents of the government (notably the Scout Corps) has any physical means of contacting the distant alien nations.
With its large population, wouldn't Aldea be quickly gaining on Mars as humanity's second planet?

Yes, Aldea is the most influential of the colonies. Mars still has more industry, however, as they got a 50-year head start and specialize in industrial production. Mars is a haven for industry, as many activities that would be considered polluting on other worlds are considered beneficial on Mars. 

The Terran Fleet and Scout Corps

Humanity's space forces have three tiers: the local system authorities have their own police ships (mostly frigates) that are responsible for in-system affairs. The Colonial Fleet is responsible for patrolling the interstellar trade lanes and responding to emergencies and violations of treaty (assisting the local police when called upon). The Scout Corps is responsible for deep space exploration, and patrol and search & rescue in systems that are not on the regular trade routes.

Humanity has many more starships than are directly involved with the Alien Contact mission (including military warships), but few that can travel such a long distance without resupply. Which is why the Scout Corps (whose peacetime job is deep-space research) got the call. For a list of active Terran military vessels as of the time of Alex's departure from Esperanza, 17 May 2160, see the Terran Ship Classes entry.

Colonial warships are armed with a combination of point-defense laser turrets, heavy lasers, mass driver turrets, and missile tubes. The Bennet-class scout is armed with two missile tubes and a single point-defense twin-laser turret. The "modified-Bennet" refit adds a third (rear-firing) missile tube, and two medium mass-driver turrets port/starboard.

The five main ships involved in the Alien Contact mission are Pellew, Utsumi, Bellarmine, Matveyev and Prabhu.

The standard armament for Terran warships includes lasers, mass drivers, and missiles (nuclear-tipped and otherwise). Terran missiles are primitive by Loroi or Umiak standards (they probably have about a 12G burn; the Tempest could easily outrun them), but Bellarmine did have them.

Out of curiosity, how does this rank up to the Loroi/Umiak fleet technologies, size, and numbers?

Numbers-wise, there are about as many ships in the Tempest's squadron (28) as in the whole Terran fleet. You can compare classes and sizes of Loroi and Terran ships here and here, respectively.

Tech-wise, the major combatants are about three generations ahead of the Terrans; Humanity is in the later stages of TL9, while the Loroi and Umiak are in the very early stages of TL11. Terran vessels have no defensive screens, and are limited to about 6G acceleration. Loroi and Umiak ships can typically sustain 26G acceleration, and their beams weapons do a lot more damage at much greater ranges than Terran lasers (although the Loroi do still use lasers for point-defense weapons, and are considered quaint for still using them). The Loroi were using weapons and systems similar to what the Terrans have now in the war with the Delrias that formed their empire some nine hundred years ago. Terran weapons are capable of damaging Loroi vessels, but only at very close range.

I'm surprised (except for space considerations) that the Bellarmine wouldn't have an aft "chaser" torpedo tube-if only to keep people away from it while it's running away at full speed for the hyperspace limit.

Bellarmine's weapon systems were an afterthought; she wasn't really designed as a warship. But torpedoes fired from the forward tubes can track a target no matter where it is. Torpedo combat is long-range combat. The ejection from the tube is just to get the torpedo far enough from the launching vehicle so that it can safely light its drive.

Humanity has a large stockpile of nuclear weapons. Can't we use them as some sort of weapon in this war?

I don't think current nuclear warheads have anywhere near a 158 year lifespan, but no doubt there will be plenty of new and effective warheads at hand in 2160. Such warheads are relatively cheap; it's the devices required to deliver them on target that are expensive. A missile that can reliably deliver a warhead to a 30G accelerating target at 1 light-second range is beyond human technology in 2160.

That said, nukes are still nukes, and kinetic energy is still kinetic energy. Under the right circumstances at close range, a Terran warship could do very significant damage to a Loroi or Umiak vessel. The problem is achieving those circumstances.

Do we have carriers? or do the heavy cruisers carry a significant number of fighters? I know that a fighter won't be very effective but alas they are so glamorous.

Humans do have unmanned fighters that operate from bases and stations, but they haven't yet built any carriers. The other warships have shuttle bays that could theoretically carry a small handful of fighters. If the need arose, a transport could conceivably be converted into a makeshift light carrier.

From what I understand, Humanity is completely and utterly boned in this galactic war because from what I can see we are trounced in all comparable aspects with the Loroi and Umiak. Aside from having our civilization turned into either slave labor or being completely devoted to an industrial planet I can't think of anything the Terrans can or could do. Do they have anything to offer besides inferiority?

I get this question a lot, but it's a little bit like asking, "What could Hobbits possibly offer in the war against Sauron?" The question can't be answered without telling the story.

Alien Contact

On October 31 2158, an alien vessel stumbled into the 82 Eridani system, which was the site of Humanity's Esperanza colony. After a great deal of alarm from the Human colonial installations in system, contact was made with the alien vessel by the Scout Corps transport ECS-052 Tartakovsky. Although it would take some time to establish effective communications with the aliens, it became quickly obvious that they were not hostile. On the contrary, it was a transport filled with civilian refugees of an alien species who identified themselves as the Orgus. At length they were able to communicate that they were fleeing a massive conflict between two star-spanning empires: the Loroi and Umiak and their various allies.

The Orgus had been a small nation located on the periphery of what would eventually become the Umiak sphere of influence. As an interstellar presence, the Orgus would probably have been just a stop on the long ancient trade routes, sort of an oasis on the dusty and largely disused “silk road” between distant civilizations farther up the Orion galactic arm, and the nations of the Local Bubble that were soon to come under Umiak domination. As the Umiak Empire began to grow, the Orgus (and other nearby nations) would have been known to the Umiak, but not of much interest to them. Even after the start of the war and the resulting aggressive Umiak expansionism, it would have been difficult for the Orgus to believe that one day there would be Umiak warships knocking on their door. Even as late as the Tithric incident in 2141, there may not have been much alarm regarding the Umiak announcements of non-neutrality, partially because the Orgus and their neighbors were not near the borders with the Loroi, and partially because the Umiak were still then a remote power whose threats were not taken seriously. It was not clear at the time that the Umiak would take the non-neutrality doctrine as license to annex their neighbors.

Some time early in 2158, the Umiak launched an unexpected attack on Orgus territory, and quickly defeated the Orgus defenders. The Orgus who arrived at Esperanza were a collection of refugees that had gathered at a remote trade outpost at the edge of Orgus territory. Some would have been returning from abroad, and some fleeing interior areas. What they would have in common is that none would have much information on what diplomacy (if any) preceded the Umiak military action, nor many details about the invasion itself, once it had taken place, as no information left a system once the Umiak had taken control of it. The Orgus refugees did not know what the Umiak had in store for them, be it genocide, oppressive occupation, reorganization, or merely some more benign form of control. Those Orgus still in outlying areas who had decided not to submit to the Umiak fled in what transport they could arrange.

The ship the Orgus arrived in at 82 Eridani was a freighter that had been returning to Orgus space from outlying areas. They removed the cargo and filled it with as many refugees as it could sustain. Many such ships attempted to flee Umiak dominion, mostly to destinations that were previously known, along the existing trade routes. However, most of the nations surrounding the Orgus had already agreed to some form of affiliation with the Umiak, so some ships did not take the direct routes through the silk road, but instead took detours that they believed could eventually deliver them to the desired destinations. Some detours required making jumps that had not been tested for millennia. Some ships did not survive the attempt. That this vessel found a Human colony at 82 Eridani was unexpected. Rather than continue the hazardous search for an alternate route up-arm, these Orgus surrendered themselves to the Terran authorities at Esperanza, and their flight ended. Several thousand Orgus offered their ship and their combined knowledge in exchange for sanctuary.

What did the Humans learn from the Orgus?

The Orgus transport was a civilian vessel that did not have weapons or defensive screens, but the engines, infrastructure and materials are ahead of what the Humans have, though not up to the standard of the major combatants. The ship and many of the refugees' personal items have been (politely) confiscated by the Terran authorities and are under intense study.

The refugees eagerly supplied Terran intelligence with detailed information on Orgus space and the trade routes known to them. In this sense, Humanity may know as much or more about some of the peripheral races and the ancient trade routes through that sector as the Umiak do. This information is they only way that Terran scouts could have arrived along the axis of Loroi/Umiak conflict.

Was the existence of the aliens kept secret or announced to the public?

The existence of the Orgus and the war is common knowledge. The degree to which the Humans are outclassed and the genocidal nature of the war is probably not common knowledge. You have to tell the population something... you can't gear up a democratic society for total war without explaining why it's necessary.

Where are the refugees now? (All on one planet? Spread out?) What is their status in Terran Society?

The Terran Colonial Authority took custody of the Orgus ship, crew and passengers, though the ship and most of the Orgus remain at Esperanza due to issues of local sovereignty. Many of the Orgus have been transported to other locations, mostly Earth, to serve as experts and teachers, especially regarding the Trade Language and the locations of the trade routes, on which some Orgus individuals were aids in teaching classes at the TCA Academy (which Alex attended).

The Orgus are aliens who have requested sanctuary. The current TCA charter does not recognize the rights of aliens, so the status of an Orgus is dependent upon what human nation it resides in, and what deals have been made. The existence of the Orgus has not been kept a secret (as one can hardly expect to place six planets on a war footing with no explanation), but they have certainly been kept under the tightest security, for a variety of reasons which I'm sure you can imagine. As you can expect, each and every one of the Orgus expatriates has been closely interviewed by the Terran authorities, and their movements are carefully controlled.

How did they react to the possibility of the humans allying with the Umiak?

It is unlikely that the Terran authorities discussed any of their plans for the survival of humanity with alien refugees.

Did the Loroi know of / meet the Orgus prior to the Umiak attack?

The Loroi had no direct contact with the Orgus prior to the war. Orgus territory is located on the other side of Umiak territory from the Loroi, and even before the war, the Umiak did not permit unauthorized vessels to pass through their borders. Loroi knowledge of the region beyond the Umiak "iron curtain" would be limited to ancient legend perpetuated by the Historians, and what Loroi intelligence could obtain from the races they came into contact with. The Orgus refugees, never having met a Loroi, certainly know them by reputation and (Umiak-supplied) propaganda.

The Bellarmine Incident

The second (and third, and fourth) strike against the Bellarmine should indicate that the attack was no accident. And 850 kilometers is considered very close range here; especially since some of the combatants are over 1 km long. Bellarmine herself is (or rather was) 190m in length.

When the second strike "ignited" the Bellarmine's fuel tanks, what sort of fuel ignited? If it was 5,000 tons of anti-matter, we wouldn't be enjoying this comic 'cause our friend Alex would be a spike in the universal background radiation level. If it was hydrogen, what ignited? Did the energy weapon strike cause the hydrogen to fuse, resulting a massive explosion? Or was this a "mechanical" explosion - the liquid/slush hydrogen was rapidly converted to gas by the energy weapon strike, and we're seeing the equivalent of "steam explosion".

The Bellarmine's main tanks would have been liquid hydrogen, fuel for a fusion drive. Secondary tanks would have contained oxygen and other substances. I'm not enough of a physicist to know exactly what will happen chemically to liquid hydrogen when you subject it to intense heat in the direct absence of oxygen, but as you've suggested there would be at the very least a pressure explosion (as the fuel tank was ruptured), and there was enough oxygen in the vicinity (from storage tanks and escaping atmosphere) to create a noticeable fireball. I don't think the fuel would have reached fusion temperature; I assume a thermonuclear explosion at such close range would have been inescapably lethal to Alex. So, technically only a portion of the fuel would have "ignited" -- that is, burned chemically as a result of contact with oxygen.

Isn't it unwise to send out manned scouts, thus declaring our existence to the combatants? Wouldn't unmanned, remotely controlled probes have been a better idea? And why was the Bellarmine sent out alone? Sounds like the mission was set up to fail.

The problem with sending an unmanned "probe" is that there is no faster-than-light communication by which to relay information back to base; the ship must return with a report. So, there is no such thing as a "remote control" starship.

As for having an AI control the ship, I don't see the advantage. The same steps can be taken to "sanitize" a manned ship information-wise to prevent an enemy from learning the location of Earth as can be taken with an unmanned ship, but remember that the whole idea was to eventually make contact; according to their intelligence, eventual contact with the warring parties is inevitable. Both sides are expanding in attempt to gain needed resources. As for the choice of whether to hide or attempt contact, this issue has already been discussed. The story of Humanity cowering in a hole until the Umiak arrive to conquer them wouldn't have made for a very interesting storyline, in my opinion. The scout's intention was to gather intelligence first and contact second, as the Bellarmine was attempting to do; that there happened to be a hostile vessel in their lap was unforeseeable bad luck.

And as far as contact is concerned, the idea is that the scouts must be able to make decisions on the spot, as they can't call home for instructions. Would you want to trust an AI with the future of your species? I wouldn't. Programmers are very clever people, but communications with other sentient beings is not their strong suit. (I should know, I'm a programmer.)

Time is an important factor to Humanity. Hostile scouts could discover Earth tomorrow or five years in the future. It has already taken more than 6 months to organize the contact mission, and the Bellarmine spent almost two months making the 200 light year journey; to report back takes another two months. There isn't a lot of time to waste.

Why send in Bellarmine alone? If ships were sent in pairs, one could stay at the jump point and report if the other was destroyed.

Humanity doesn't have an unlimited supply of long-range starships. The Scout Corps only has six such ships, and four of them are involved in this mission (along with a fifth long-range transport that serves as a refueling point and relay station between the scouts and home base). Not knowing the precise location of either the Umiak or Loroi, the planners chose to spread their 4 scouts across a large area, hoping to find what they were looking for. Two groups of two ships each is, in my opinion, putting too many eggs in too few baskets. The Bellarmine has been destroyed, but there are still three other scouts out there.

See also: Terran Warship Classes