Some very bright and very rare or very unusual stars may make good landmarks, but for only comparatively short segments of our journey. Red supergiant stars, for example, are rare but very bright, so they could be seen for reasonably long distances. There are also variable stars—stars whose brightness oscillates from bright to dim back to bright over the span of days or weeks—that would make good short-term landmarks. The period over which a variable star’s brightness changes is unique for each star, making them interesting targets as landmarks. It is unlikely, though, that the Colonials have a comprehensive database of every red supergiant or variable star in the Galaxy. Even if they did, views to these stars would eventually become obscured by the vast amounts of dust present in the plane of the Galaxy and swamped amidst the countless stars that compose the disk of the Milky Way. These would make excellent landmarks, but for segments of the journey only.
What about the center of the Galaxy, the galactic bulge? To triangulate the Rag Tag Fleet’s position within the Galaxy, this would be an excellent starting point. One of the ways in which modern spacecraft determine their position is by a process called optical navigation, or OPNAV. Let us use the Cassini spacecraft orbiting Saturn as an example. By taking an image of one of Saturn’s moons, and comparing that to the fixed backdrop of stars behind it, navigators can narrow down the Cassini’s position. As Galactica moves through the Galaxy, the galactic core would appear to move against the backdrop of the distant galaxies. Although it is in the plane of the Galaxy, along with countless billions of stars, the core can still be resolved. Even though there are also vast clouds of dust in the plane of the Galaxy that obscure line-of-sight tracking of objects like individual stars and nebulae over large distances, electromagnetic radiation in the infrared portion of the spectrum passes through dust more readily than does light in the visible portion of the spectrum. Therefore, if Galactica has an infrared telescope, they could resolve the galactic core from any place within the Galaxy. By determining the position of the core relative to the galaxies of our reference frame, like a modern spacecraft OPNAV, Galactica could determine their relative bearing to the core of the Galaxy. This would not pinpoint Galactica’s position within the Galaxy, but it would be an excellent first step.
Are there any other landmarks, like the galactic core, that appear to move relative to our fixed backdrop of distant galaxies? As a matter of fact, there are. Recall from chapter 15, “Our Galaxy,” that the Milky Way is surrounded by a halo of globular clusters. These structures are not only large enough to be seen over very great distances, but most are out of the plane of the Galaxy, and hence are easier to see from a spacecraft immersed within the Galaxy. They are also close enough to the Galaxy that as Galactica moves through the Galaxy, they would appear to move relative to our inertial reference frame. As galaxies go, the Milky Way is a fairly large one. Orbiting the Milky Way are other, smaller galaxies. In particular, there are two irregularly shaped galaxies that can be seen only from the southern hemisphere. They appear as two wispy clouds in the night sky, and are called the Large and Small Magellanic Clouds. These, along with other “nearby” galaxies, could serve the same function as the globular clusters that ring the Milky Way—they would make excellent navigation aids, they are visible over vast expanses of our Galaxy, and they would move against the fixed backdrop of distant galaxies as a spacecraft moves through the Galaxy.
The universe has, in fact, provided Galactica and her Fleet with a relatively easy way to navigate across the light-years from the Twelve Colonies to Earth. Perhaps when we see negative star images on Galactica’s plotting table, we’re seeing the Colonial equivalent of an OPNAV—images taken to locate distant reference galaxies or closer landmarks. With distant galaxies chosen to form a fixed, or inertial, reference frame, and by using the galactic core, globular clusters, nearby galaxies, and interesting stars like red supergiants and variables as landmarks, getting lost in the vast expanse of the Milky Way turns out to be toward the bottom of the Rag Tag Fleet’s list of concerns.
But how can we forget the episode “Home, Part II”? An away team finds the Tomb of Athena on Kobol and activates a holographic planetarium show, displaying the night sky as it appears from Dead Earth. Lee Adama points to a fuzzy patch of light, identifies it as the Lagoon Nebula, and claims, “At least now we have a map. And a direction.”
Like constellations, nebulae have dramatically different appearances when seen from different vantage points. This is a little helpful as a navigation tool, but only a little. The Lagoon Nebula would have the same appearance as it does from the solar system for a fairly narrow range of viewing angles. That’s the good news. On the other hand, recall that although visible from Earth, the Lagoon Nebula is really not in the solar system’s neighborhood, it is 4,100 light-years—820 red line jumps—away. Let’s assume that the Lagoon Nebula appears, more or less, the same within a cone of 5 degrees from a line adjoining the solar system and the nebula, which is a conservative estimate. The volume of a 5-degree cone 4,100 light-years in length is 552 million cubic light-years. Given that there are approximately 300 billion stars in the Milky Way, that means there would be approximately 5.2 million stars in that cone. If 10 percent of those are stars that could have habitable planets, that leaves only 520,000 potential locations for Earth. Although that is a much smaller search space than 300 billion, it is still hardly a manageable number. The Colonials would need a lot more information to find Earth, which they obviously get ultimately.
A more intriguing question is “How did Apollo recognize the Lagoon Nebula in the first place?” Perhaps from sacred scripture? Certainly if it’s a known object in the night sky of the Twelve Colonies, and it has roughly the same appearance there as from Dead Earth, then the Twelve Colonies, Dead Earth, and the Lagoon Nebula are all, more or less, along a straight line in the Galaxy. In fact, since the Lagoon Nebula and the galactic core are in the same portion of the sky as seen from the solar system, then the galactic core, the Lagoon Nebula, the solar system, and the Twelve Colonies are all close to being collinear. Similar to the previous argument, this narrows the search space dramatically, but still leaves a large number of stars through which they would need to comb. If the Twelve Colonies were even twice the distance from the nebula as Earth, then the cone in which they would need to search for Earth has a volume of 4.4 billion cubic light-years, and it would contain approximately 41 million star systems. If 10 percent of those were habitable, the Fleet would be looking at a search space of over 4 million stars. “Needle in a haystack” is trivial in comparison.
CHAPTER 25
Battlestars, Vipers, and Raptors
A modern carrier battle group consists of an aircraft carrier and escort ships—frigates, destroyers, and cruisers—that act as both anti-air and anti-submarine shields for the carrier and supply ships of the battle group. Although the Colonial warships seen throughout the series have been battlestars (including Galactica, Pegasus, Columbia, Valkyrie, and Yashuman), the Twelve Colonies obviously operated smaller combatant ships like those in today’s battle groups. In “Razor,” although the battlestars Bellerophon and Ramses were docked at the Scorpia shipyards with Pegasus, several smaller vessels were also present. Further, in the episode “Daybreak,” William Adama says, “I’ve commanded two battlestars, three escorts before that.”
Since the initial design of a military vessel represents a large fraction of the cost of a ship, it makes economic sense to build multiple copies of the same design. Therefore the navy does not simply build the destroyer U.S.S. Arleigh Burke, it builds sixty-two Arleigh Burke-class destroyers all having (roughly) the same design, The same is apparently true of the Colonial Fleet. In the episode “Pegasus” we learn that Galactica is a Jupiter-class battlestar, while Pegasus is a much newer Mercury-class.
Lee plays a game of triad.
Lee pins Starbuck’s picture on the memorial wall.
We’ll be in too close for nukes. Same goes for missiles. This’ll be strictly a gun ba
ttle. Like two old ships of the line slugging it out at point blank range. Let the gun captains know their job is to fire and keep firing until they run out of ammo. Then they should start throwing rocks.
—Admiral Adama, Battlestar Galactica, “Daybreak, Part II”
It’s tempting to think of a battlestar as simply a space-based aircraft carrier. However, since battlestars are heavily armored and are also armed with serious firepower, they are more akin to a hybrid aircraft carrier/battleship.
To defend herself, Galactica has multiple batteries of kinetic energy weapons, or KEWs. Remember that at the beginning of the book, we described kinetic energy as the energy a body possesses because of its movement? In that way, slingshots, catapults, guns, rifles, and cannon are all kinetic energy weapons; they cause damage simply because of the combined mass and speed of their projectiles. We also said that kinetic energy was easy to transfer from one body to another. When these projectiles transfer their huge kinetic energy to an enemy target many meters or even kilometers away, some of the kinetic energy becomes heat, and some of the kinetic energy is transferred directly into the target, either blowing a hole in it or imparting momentum to it (or both).
The Battlestar Pegasus.
As we previously discussed in chapter 9, “Energy Matters,” the most commonly used unit of energy is the joule. A two-kilogram mass traveling at 1 meter per second has a kinetic energy of 1 joule. A 100-kilogram (about 220 pounds) NFL halfback running at 6 meters per second has 1,800 joules of kinetic energy. By comparison, a round of .223 caliber ammunition, used by the U.S. military’s standard issue M16 rifle, has over 1,750 joules of kinetic energy. A single bullet from an M16 hits as hard as being flattened by an NFL halfback. That’s the whole point behind a bullet. When the bullet strikes the target, its small size helps to focus the kinetic energy at the point of impact, giving this tiny hunk of lead a punch like a laser beam.
Battlestar rail guns.
While bullets, cannonballs, and other forms of nonexplosive projectiles can be considered KEWs in the broadest sense of the term, in modern terminology the term KEW has a narrower connotation. Kinetic energy weapons are designed to launch projectiles that impact a target at incredibly high rates of speed. Battlestars are equipped with rail guns that fall into this category. A rail gun uses magnetic fields to accelerate a metallic projectile. In 2008 the U.S. Navy successfully tested a rail gun that accelerated an eight-pound projectile up to seven times the speed of sound. The navy currently plans to use rail guns that fire projectiles at eight times this energy when they finally become operational within the Fleet—the equivalent energy of launching our NFL running back at the muzzle velocity of our M16. Clearly, KE weapons don’t have to be extremely complex to be extremely effective; rail guns deployed in the real world within the next few years would be powerful enough to pierce the armor of even Galactica herself.
Galactica is also armed with nuclear weapons, but as counterintuitive as it might seem, a metal rod accelerated to high velocity is likely to be a far more effective weapon against an armored spacecraft than a nuclear warhead. As we saw, Galactica’s armor could stop all, or nearly all, of the explosive force of a nuke from doing damage to the crew or to the ship itself.
The ionizing radiation released by a nuclear weapon, though, generates a burst of electromagnetic energy that can burn out unshielded electronic circuits. A battlestar’s electronics would partially be protected by its metallic hull, but sensors on the outside of the ship would be particularly vulnerable. A Cylon ship, in which a large percentage of the ship’s structure is organic, would likely suffer more damage from thermonuclear radiation than a battlestar.
Finally, nearly half the energy of a nuclear weapon detonation is the blast wave that propagates away from the explosion at nearly the speed of sound. This is actually a good thing, because in space no one can hear your nuke going off. Without any air, there is no medium to propagate a blast wave. Nuclear weapons would lose much of their effectiveness in space because of this.
Although a battlestar has a formidable array of weapons, it is her fighters that are her main offensive punch. On aircraft carriers, airplanes are launched from the flight deck using steam-driven catapults. The aircraft crew locks the aircraft’s nose wheel onto a piston in the deck. An enormous amount of potential energy—in the form of steam pressure—builds up behind the piston. When the pilot signals for takeoff, the piston is freed and the steam pressure becomes kinetic energy driving the piston (and the attached aircraft) down the carrier’s launch rail. Given this burst of speed, the aircraft is able to gain enough lift to achieve flight. The system is then rewound, a new aircraft is mounted, and the process begins again with the buildup of more steamy potential energy.
A battlestar’s whole purpose is to launch Vipers.
—Specialist Dealino, “Daybreak, Part I”
One of the drawbacks of this system is that each catapult shot uses up to 614 kg of steam. This may work well on a ship surrounded by water, but on a battlestar in space, where H2O is a precious commodity, spacecraft would have to launch using another method. Like the next-generation aircraft carriers currently under construction, the catapults in Galactica’s launch tubes—magcelerators, or “mag cats”—are magnetically driven. Using a concept similar to that of rail guns, magnetic fields are used to propel a metal shuttle down a launch rail. When a Viper is attached to the shuttle, the fighter is flung into space.
Vipers launching from a battlestar.
A noticeable difference between the 1978 Battlestar Galactica and the reimagined incarnation is the procedure for launching Vipers. A constant from the original series was Corporal Rigel’s calm and steady voice: “Core systems transferring control to Viper fighters. Launch when ready.”
In the reimagined Battlestar Galactica, a launch officer goes through the same formal checklist every time a Viper is launched: “Viper two-eight-nine/Galactica, clear forward, nav-con green, interval check, thrust positive and steady. Mag cat engaged. Good-bye, Starbuck.” In the original series the decision of when to launch rested with the pilot.
In the reimagined series the decision if and when to launch rested with the launch officer, which is deliberately more like the way a plane is launched from a carrier today. It also made more sense from a physics standpoint; in the original series the energy to launch a Viper came from within the Viper itself, thus consuming valuable fuel. In the reimagined series, Galactica brings the Viper up to launch speed externally, a much more energy-efficient way of doing business.
Vipers
If Galactica is an aircraft carrier in space, then Vipers are her fighter aircraft—single-seat multimission fighters used primarily for air and space superiority, but with limited ground-attack capability. Like today’s fighter craft, they also have limited electronic countermeasures (ECMs) capability as well, as shown by the small pod mounted on the vertical stabilizer.
This is the Mark II Viper. It’s nimble as a jackrabbit, and anyone not paying attention is likely to become a pile of muck that needs to be hosed out of the cockpit by the chief of the deck.
—Lt. Kara “Starbuck” Thrace, “Act of Contrition”
A purely space-based fighter would not need to be shaped aerodynamically, since the lack of atmosphere makes aeronautical control surfaces like wings, elevons, a tail, or a rudder meaningless. The Viper, however, is capable of flight within the atmospheres of different types of planets and moons. Since the Viper’s engines aren’t necessarily “air breathers”—they don’t intake air surrounding the craft for use as an oxidizer to generate thrust as a jet engine does—they can fly in just about any atmosphere. Each atmosphere does present its own peculiarities and challenges for the maintenance crew, however.
A Mark VII Viper.
Although we’ve seen Vipers deploy air-to-ground munitions (“The Hand of God” and “Exodus, Part II”) and air-to-air missiles (“Blood on the Scales”), a Viper’s main weapons are its twin wing-mounted cannon. In the episode “
Epiphanies,” in which Chief Tyrol and his flight crew discover that somebody has been tampering with Viper ammunition, we see that Viper KEWs appear to be belt-fed medium-caliber weapons using chemical propellant to fire solid or explosive rounds. They are very similar to the 20 mm rounds fired by the M61 cannon mounted on all U.S. military fighter aircraft today, with one obvious implied exception. Since Vipers operate in space, the casing for each round must not only contain a propellant like gunpowder, it must also contain an oxidizer. Some ammunition being developed today has both propellant and oxidizer molded to form a temporary case, which is “burned” when the round is fired.
For Battlestar Galactica, executive producers Ron Moore and David Eick made the decision that Colonial armaments would fire projectiles instead of the more traditionally science fictional lasers. Those white flashes that some people think are short laser pulses are really tracer rounds—bullets coated with a pyrotechnic material that burns when the round is fired, glowing very brightly. By putting in one tracer for about every ten regular bullets, the shooter can see where the bullets are going and can more accurately adjust fire.
The producers’ choice to endow Vipers, Colonial Marines, and battlestars with projectile weaponry was initially met with cries of “Luddites!” from fans when the miniseries initially aired. For many fans, lasers simply seem more . . . lethal than a high-speed chunk of lead or depleted uranium. If you still feel that Vipers could have been made to seem more capable, let’s examine how efficiently both types of weapons deliver lethal energy to their targets.
The Science of Battlestar Galactica Page 21
