Halo (megastructure)

From Wikipedia, the free encyclopedia

Halos are fictional megastructures in the Halo video game series.

In Amber Clad approaches Installation 05, otherwise known as Delta Halo

[edit] Overview

A Halo is one of the seven habitable megastructures that exist within the Halo science fiction series. The Halos are portrayed as thin (with respect to their overall size) ring-shaped constructs, thousands of kilometers in diameter. Only two of the seven Halos, Installations 04 and 05, have been seen within the games. In its present state, the Halo universe only has six installations left, as one is destroyed at the end of Halo: Combat Evolved.^[1]

Each installation shown in the series has a monitor to oversee automated installation functions, such as defense and climate control.

The Halo installations were built by the Forerunners, a fictional civilization within the series. The installations were built to contain and study the Flood, a rampantly infectious alien parasite. In the event the Flood are released, it is the responsibility of the Monitor of that Halo to activate the ring's last resort - a super-weapon capable of destroying all bio-mass of notable size in the galaxy. This would effectively starve the Flood into defeat. The only demonstrated method of activation is through the use of a "Reclaimer", which is mentioned in greater detail below. Installation 04's "maximum effective" range, according to the Monitor, is a radius of 25,000 light years. The activation of one ring's super-weapon causes the other six Halo installations to activate and fire as well, extending the range to the entire Milky Way galaxy. In Halo 2, the Monitor states that if all stations fired simultaneously, the range would be "three radii of the galactic center." The actual method of destruction has never been stated beyond that it is radiological in nature, but it has been established that it would only destroy bio-mass large enough to sustain the Flood. Remarks made by Installation 04's Monitor, the artificial intelligence construct 343 Guilty Spark, indicate that the Installation's "research facilities are most-impressive".

The Halo Installations were only part of the Forerunner plan to starve out the Flood. As revealed in the Halo novel Ghosts of Onyx, the Forerunners also constructed Shield Worlds. The design of these are based on the theory of a Dyson sphere, but in this case are contained entirely within Slipspace; its actual occupation in Real-Space being a diameter of perhaps a meter. The Slipspace field which contains the Shield world also protects it from any and all attack by 'Real-World' interference; most importantly, and by design, to withstand the activation of the seven Halo constructs. It is unknown how many Shield Worlds exist, but it is suspected that it would be seven, or some other religiously significant number, based upon the style of the Halo universe.

An island, referred to as Relic, on one of the massive Halos.

The outer surface of a Halo is mechanical in appearance, but its exact nature has not been mentioned in detail within the series. Its inner surface features various ecosystems, with rivers, mountains, plains, oceans, deserts, arctic tundra, and other normal features of terrestrial geography. The inner surface experiences artificial gravity. Halo installations experience a permanent half-day/half-night situation, and because they are generally depicted vertically oriented compared to a system's ecliptic, it does not appear that the ring would cast a shadow on itself. Since a player can spend considerably longer than an hour in video game levels set on one of the Halo installations, without any change in lighting conditions, the day/night cycle takes longer than one hour. Thus, the presence of additional artificial gravity generating devices is likely. This is confirmed by the A.I. Cortana upon Alpha Halo's discovery at the end of the book Halo: The Fall of Reach where she detects artificial gravity on the ring and thus concludes that it cannot be a naturally occurring celestial object.

The Halos are superficially similar in shape and design to the "Ringworld" from the 1970 science fiction novel by Larry Niven. While the Halos have diameters of approximately 10,000 kilometers , the Ringworld surrounds a star and has a radius similar to Earth's orbit (about 95 million miles). The Halos are much smaller than Larry Niven's Ringworld, and are closer in scale and structure to Iain M. Banks' Culture Orbitals. While the diameter of Niven's Ringworld is close to the diameter of Earth's orbit of 150 million km, and the standard Banks Orbital is around 14 million kilometers in diameter, the 10,000 km diameter of Halo is much closer to the diameter of Earth itself, which is 12,756 km.^{[citation needed]} Ringworld has a star similar to our Sun at its center of mass, whereas the Halos may orbit planets but do not encircle them.

[edit] Installation 04

Also known as Alpha Halo, this was the first Halo to appear in the Halo series. The entire game of Halo: Combat Evolved is played on the ringworld, with the exceptions of the first level, which takes place on a UNSC cruiser (Halcyon-class) called the Pillar of Autumn, and two levels set aboard the Covenant cruiser Truth and Reconciliation, which floats a few hundred feet above Alpha Halo's surface. Installation 04 is in orbit around the gas giant Threshold, at the Lagrangian Point between the gas giant and one of its moons, Basis, in the Soell system.

Installation 04 is confirmed to be, at the minimum, 101,217 local years old, a local year being the amount of time it takes Threshold to orbit its star.{fact|mar2007} In an interview with Joe Staten of Bungie Studios, Staten also confirmed that the previous firing to which 343 Guilty Spark alludes, occurred around 100,000 years previous to the events in year 2552 at Installation 04.{fact|mar2007}

At the end of the events of Halo: Combat Evolved, the Master Chief and Cortana destroy Installation 04 by detonating the fusion reactors of the Pillar of Autumn on the ring. The resulting nuclear explosion destroyed enough of the ring to allow the installation's momentum and rotation to over-stress the remainder of the structure, causing it to tear itself apart and destroying a significant portion of the Covenant armada surrounding the installation.

[edit] Threshold and Basis

The Gas Giant Threshold.

Of additional note is the fictional gas giant Threshold. The entire game of Halo takes place in Threshold's orbit, and parts of Halo 2 take place on installations in its atmosphere. The gas giant measures about 214,604 kilometers in diameter^[2], larger than the planet Jupiter. The atmosphere of Threshold, or at least one layer, is breathable by Covenant Elites. At this layer a large Forerunner gas mining facility is located, which remains operational, and is patrolled by 343 Guilty Spark's Sentinels, as of Halo 2's time frame. The exact purpose of the gas the facility gathers is unknown. In a Halo 2 level that takes place on Installation 05 (which is not in the same star system as Threshold), empty gas canisters similar to those in the mining facility can be spotted, just inside the outer doors of the Library, which may provide some clues to its use. Additionally, the Heretic Grunts breathe this gas, indicating it may be a processed form of methane gas.

During the Forerunner's, ' conflict with the Flood, a portion of the facility hanging below the rest of the structure was refitted into a research lab, to study the Flood. 343 Guilty Spark stated that it personally oversaw the construction of the facility's outbreak management systems.

Shortly after the destruction of Installation 04, at the end of Halo: CE, the gas mining facility is taken over by a renegade group of Covenant, referred to in-game as The Heretics. The Heretics rebel from the Covenant upon recovering 343 Guilty Spark from the space around Installation 04, and after learning of Halo's true nature as a weapon. Later, in the events in Halo 2, the Arbiter, one of the two playable characters in Halo 2, is dispatched with a team of special operations Elites and Grunts to quell the rebellion. At some point before their arrival, the Flood specimens stored in the labs break free, and attack any forces they find. In response to Heretic movements, the Arbiter cuts the bottom portion of the station loose, kills the Heretic leader, and escapes, leaving the research lab to fall into Threshold's lower atmosphere.

Threshold's moon, Basis, measures at 23,848 km in diameter,^[2] and features a breathable atmosphere. Debris from Installation 04's destruction litters the lunar surface, and among the pieces of this debris is a temporary base camp set up by the Heretic forces, who later relocated to Threshold's gas mining facility. Aside from this, little is known about Basis.

[edit] Astronomy

A diagram showing the five Lagrangian points in a two-body system. Threshold is the yellow circle, Basis is the blue circle, and Alpha Halo is positioned at L1.

Besides the very carefully sculpted landscape on Halo's surface, the sky in the video game is also worthy of attention. Depending on the viewpoint, the player can see the star, the gas giant Threshold, the gas giant's moon, Basis, and the band of Halo itself, which curves upward to a point directly overhead.

Installation 04 is positioned on the Lagrange point L1 of Threshold and Basis, directly between the two celestial bodies, but closer to Basis. At the Lagrange point L1 the gravity of Basis and Threshold partially cancel out, giving Halo the same orbital period as Basis despite being in a closer orbit. The rotational axis of Halo is perpendicular to the line between Threshold and Basis, so that, when viewed from Halo, the moon and the Planet are always opposite each other, and both are about 90 degrees left or right of the ring of Halo. All three bodies revolve with the same angular speed around their common center of gravity, which is inside of Threshold, but not exactly at the center of gravity of the planet. Their common center of gravity revolves around the star.

In contrast to the Lagrange points L4 and L5, the Lagrange points L1, L2 and L3 are metastable positions, similar to a marble placed on the center of a saddle. This indicates that Halo would have to stabilize its position actively (if real laws of physics applied to it), so as not to fall onto either Threshold or Basis.

[edit] Installation 05

In Halo 2, Installation 05, also known as Delta Halo, is another one of the ring-shaped Halo installations. As such, it is of great importance to The Covenant. The Covenant believe that controlling and activating the Halo installations is required to trigger a religious event, referred to as the 'Great Journey'.

Delta Halo has submerged structures, ruins, and little-known wildlife. This Halo is the scene of many battles between the UNSC, the Covenant, the Flood, and the Forerunner Sentinels activated to defend it. All four groups seek the Index, for various reasons. Buried deep within this ring is a Flood intelligence, known as Gravemind.

The blue gas giant Delta Halo orbits is called Substance. This name is not mentioned in-game, and it can only be seen in the file for the game's texture backgrounds.

Several levels of Halo 2 take place on this second installation. When the High Prophet of Regret flees New Mombasa, East African Protectorate, he sets up a base of operations on Delta Halo (Installation 05), and attempts to activate it. The Master Chief follows the Prophet and kills him, preventing the installation's activation for a short time.

After the High Prophets and Brutes betray the Elites (a major plot point in Halo 2), the Brutes set up a base of operations in the Control Room of this Halo, in order to activate the Installation. The Arbiter and a number of Elites launch an offensive against the Brute encampment, and with human assistance (Sergeant Major Avery Johnson and Commander Miranda Keyes), manage to kill the Brute Chieftain Tartarus just in time to stop the ring from firing. However, by preventing Delta Halo from firing at the last second, this activates a fail-safe built into the Halo installations. According to 343 Guilty Spark, in event of a last minute cancellation, the installation arms the remaining Halo installations via subspace beacon, and they became ready for remote activation from a core installation, known as The Ark. This situation should be resolved in Halo 3.^[3]

[edit] Name

"Delta Halo" is the title of a specific group of levels in the Halo 2 campaign set on the eponymous second Halo installation. Although the Halo installation (Installation 05) is known as Delta Halo, it is not certain that this is the official UNSC designation for the installation.

[edit] The Libraries

Structures known as "Libraries" can be found on both Halo installations in the Halo video game series. The precise purpose of the Library facilities is unknown. In-game, the Libraries are referred to as "security complexes". Each Library contains an Index, which is the firing key for its associated Halo installation.

The Library Exterior of Installation 05.

The first Library is encountered on Installation 04, in Halo: CE, and appears circular in design. At its center stands a massive elevator, which ultimately carries the Master Chief down to the lower level of the Library, where he retrieves Installation 04's Index. The Library encountered on Installation 05, in Halo 2, appears to be much larger than its counterpart, and requires the use of gondola lifts to ferry entrants between areas of the structure. It is unknown whether both Libraries have the same construction design, as the method of entry in the two games is significantly different. In Halo (on installation 04), the Monitor transports the Master Chief directly to the Library, while in Halo 2 (on Installation 05), the UNSC and Covenant forces breach the Library from the exterior. More likely, however, is the fact the Monitor of Installation 05 is simply not available to transport them, having been captured by Gravemind.

[edit] Inside the Libraries

The interior of the Library on Installation 04.

As is appropriate for a security facility, the Libraries contain extensive security systems, including massive security doors that only Monitors can bypass, long and extensive approaches via external gondolas, and, on 05 at the very least, a massive energy shield that could only be bypassed by traveling through a huge convoluted series of walls and tunnels.

Both Libraries contained an artifact called The Index, which turns out to be the firing key for the Installation's main weapon, the device that purges sentient life in a 25,000 light year radius. The process of recovering the Index is a long and arduous task, as the individual seeking it must work through the extensive security systems throughout the Library and possibly battle escaped Flood specimens as well. The Index itself is both a physical and digital construct; it may only be transported by a Monitor such as 343 Guilty Spark, and utilized by a "Reclaimer." Installation 04's Index is seized and its data absorbed by Cortana in Halo: Combat Evolved, while Installation 05's Index is taken and utilized by the Covenant to activate that installation, before being forcibly removed by Miranda Keyes at the conclusion of Halo 2.

[edit] Sentinel Walls and Quarantine Areas

Separating the remainder of the installations' environment from the Library security structures are a series of massive walled fortifications, supporting a tremendous green energy shield that blocks off all access to the area beyond. These defensive structures are known as Sentinel Walls, due to the fact that they house large numbers of Sentinel security drones to fend off intruders and contain Flood infestation. Only by bypassing the Sentinels' security can players disengage the shield surrounding the Library, and advance deeper into the complex. Throughout the Sentinel Wall area, players encounter glowing openings in the walls, which slide open when an intruder approaches, and release Sentinel drones to engage nearby threats.

Beyond these shields is a vast stretching plain of snow and ice, an environment deliberately designed by the ring's security systems to inhibit Flood growth. This area is aptly known as the Quarantine Zone.

The skies over the Quarantine Zones outside the Libraries feature large floating structures, which are identified in The Art of Halo as "Sentinel Factories." These airborne structures are capable of manufacturing armies of Sentinel and Enforcer drones to contain Flood outbreaks.

These structures are not immune to Flood attack, however; during the events of the level "Quarantine Zone", the Flood use captured Wraith mortar tanks to shoot down and bombard at least one of these factories.

[edit] "Reclaimer"

In both Halo and Halo 2, when Flood infestations break out on a Halo installation, that installation's Monitor attempts to carry out a failsafe protocol. The Monitor locates a "Reclaimer", who is instructed to retrieve and use the Index, a key-like object which is used to arm and fire the Halo installation's primary weapon.^[4] This action sends initiation signals to the other Halo installations, which arm and fire as well, to ensure complete cleansing of sentient life within the galaxy. In both Halo and Halo 2 the Reclaimer is a human being, but any precise requirements for a Reclaimer, if any, are not known. It has been implied through the final level of Halo 2 that only humans can act as Reclaimers, through Tartarus' attempts to force Miranda Keyes to activate Halo.

It has been implied (within 343 Guilty Spark's log in "Conversations from the Universe", and Cortana's commentary regarding the destruction of the phase pulse generators during "Two Betrayals") that it is possible for a Monitor to activate Halo without using an Index, or at least a Reclaimer.

[edit] Wildlife

The wildlife of a Halo installation is something of a mystery. Throughout both games, very little fauna can be seen. Some of the creatures that can be observed include: large birds and enormous dragon flies with slow-moving wings on Installation 05 in the levels Delta Halo and Regret along with fish-like creatures in Regret, and moth-like creatures on Installation 04 (most noticeably during the level "343 Guilty Spark"). Ambient sounds of animal calls such as birds and monkeys can be heard in various areas of Installation 04, indicating other animals may exist.

In the MacWorld video showcasing an early build of Halo, there are dinosaur-like creatures that roam Halo's surface, but they fail to make an appearance in the actual game. This is the same for another creature shown in the video, which was originally made to be ridden while on the surface of Halo. (The "Blind Wolf" as it is referred to in the documentary.) A "Doberman Gator" was also mentioned in the Halo 2 documentary. Halo game creators later stated that the animals were removed in order to make the appearance of the Flood more terrifying and unexpected.^[5] There were also technical issues with the wildlife, such as getting the creature A.I. to properly interact with other entities in the game, that the makers were unable to overcome in time to include them in the game.

[edit] See also

• Dyson sphere
• Orbital (The Culture)
• Stanford torus
• Ringworld

[edit] References

[edit] External links

• Bungie Studios
• Bungie.org, unofficial
• Halopedia - Halo Knowledge center