The Battle of Earth or Battle of Terra was a battle during the Terran-Kilrathi War.
In 2668, the Kilrathi found themselves in a logistical emergency. Though their military outnumbered the Terran Confederation's on a two-to-one basis, the humans' percentage of trained personnel (100%) far outstripped that of the Cats', and their hardware was worn and obsolete. This was attributable directly to two factors: 1) a successful raid on the Kilrathi home planet by the TCS Tarawa, which destroyed a number of dry docks and the nearly-finished carriers within them; and 2) a sudden shortage of transports, forcing the carriers to return to base for supplies and putting further miles on spaceframes that were already overworked. Between the two, the Kilrathi Empire was on the verge of defeat.
Crown Prince Thrakhath nar Kiranka, and his grandfather the Kilrathi Emperor, revealed to the leaders of the eight Kilrathi clans the reason behind the transport shortage: a sizable percentage of the transport fleet, several sixty-fours, had been assigned to transporting raw materials to the far side of the Kilrathi Empire, where a new breed of carrier, the Hakaga-class heavy carrier, was under construction. Eight-and-four were being constructed. Encased in incredibly thick armor, with six redundant launch-and-recovery bays and space and armaments for almost three hundred fighters, these ships would win the war when they came online within the year, assuming material attrition didn't lose it first. With this in mind, Baron Jukaga nar Ki'ra suggested an anathematic solution to the warrior Kilrathi: sue for peace.
On Earth, the situation was just as dire, and the human Confederation accepted peace terms. Both fleets were demobilized and many assets secured for cold storage. Some, however, were suspicious of the Kilrathi motives, remembering that surrender is unspeakably shameful to Kilrathi society. One, Admiral Geoffrey Tolwyn, arranged to be dishonorably discharged, so that he and a number of hand-picked personnel, such as Col. James "Paladin" Taggart, Capt. Ian "Hunter" St. John, his nephew Lt. Kevin Tolwyn, Admiral Vance Richards of Confed Intelligence, and Captain Jason "Bear" Bondarevsky, could take a small number of Wake-class escort carriers (including the Tarawa) to the Free Republic of the Landreich, where vigilance had not lessened. From there a reconnaissance mission was launched into the depths of Kilrathi territory, using humanity's best detection equipment, a stolen Kilrathi cloaking device, and some sheer luck in cryptology.
Tolwyn, on Earth, had a phony signal broadcast, announcing that a key missile plant on Luna had been destroyed in an accident; soon, Kilrathi transmissions began to fly that an installation on their next target, nak'tara, was no more. This, combined with Tarawa's sensor data of the new Kilrathi Hakaga fleet—very much active, very much not secured for cold storage, and very much ready to attack—was enough to send humanity into a panic. Human carriers and fleets were hastily mobilized, but to get most of them up to full speed would take over a month, and to get their crews back would take twice that. The Kilrathi fleet was due in less than twenty days.
Prince Thrakhath came on with five new carriers and a dozen old ones, plus over seventy support ships (heavy cruisers, destroyers, etc) and over three thousand fighters. Against this, Geoff Tolwyn's Third Fleet consisted of four "old" carriers and less than two dozen support craft, and perhaps three hundred fighters. Human technology had always favored maneuverability and increased defensive technology—a decision which worked, as far more Terran pilots than Kilrathi ones survived their first engagement, and experience often played a pivotal role in battle—but numbers would undoubtedly tip the balance today. Even worse, Tolwyn was forced to play defensively; with such a tiny fleet, he could hardly afford to absorb losses, and retreated from a number of smaller colony worlds. At this point, the Kilrathi deployed their trump card: thermonuclear missiles loaded with strontium-90, set for airborne explosion. The resulting radiation would sterilize not just all human occupation, but the entire planet, rendering it uninhabitable to all life—even the Kilrathi, who (theoretically at least) hoped to take humanity's planets for themselves.
At Sirius Prime, the first of the Confederation's inner colony worlds, Tolwyn made his stand. He lost. One Hakaga carrier was crippled by four torpedo strikes (enough to kill a conventional carrier twice), and another significantly damaged, but none were destroyed; in turn, Tolwyn lost most of his bombers and fighter-bombers, two of his carriers, and almost his flagship, the TCS Concordia. Worse, he could not save Sirius; both inhabited planets in the system were sterilized, a loss of almost two billion lives. The Kilrathi lost an old-style carrier and an appalling number of fighters (nearly 600), but that would probably not make a difference. The Third Fleet retreated to Earth, ready to save it... Or die trying.
The Battle of Earth
Thrakhath, always a warrior, did not bother to consolidate his holdings before plunging straight in on Terra. The humans had managed to get three more carriers online—or, at least, to push them out of the docks and let them float in towards the Kilrathi—and had arranged a number of other distractions as well. Thousands of civilian pilots, flying unarmed and often unshielded craft -- from single-seat trainers, to enormous civilian space-liners -- volunteered to go up as decoys. Trainee pilots, some not yet out of flight academy, were rushed into combat wings to do whatever they could. Hidden behind this insanity were over two hundred Marine landing craft, packed with men, demolition equipment and Brigadier General "Big" Duke Grecko, who would lead the attack on the Kilrathi head-on: by boarding them.
While Geoff's navy fought and died, with the decoys especially dying in droves in the mass suicide mission, the Marines did their thing; none of the Kilrathi pilots, and in fact none of the Kilrathi at all, except for Thrakhath's onboard tactical-analysis personnel, realized the intent. By the time the tactical-analysts were able to warn Thrakhath of what was going on, it was too late. The Marine boarding parties that successfully infiltrated the new Hakaga carriers discovered, much to their delight, that the redundant armor was designed only to resist exterior attacks; explosions from the inside would be much, much worse. All but one Hakaga was destroyed in the resulting chaos, as well as a large number of smaller ships, and Thrakhath was forced to retreat. A single wing of Kilrathi cruisers was able to break through to Earth itself, destroying a horrific number of Earth's cities and infrastructure (a fitting revenge for the raid on Kilrah), but were not able to launch their thermonuclear warheads before being destroyed. Humanity, against all odds, had won through.
After the battle, the utter depletion of materiel and hardware combined with new revolutions in material sciences to usher in a new generation of fighters; all previous designs were retired and new ones (the WC3-era ships) entered service.
Behind the scenes
The battle was depicted in the novel Fleet Action by William R. Forstchen. It takes place about six months before Wing Commander III: Heart of the Tiger.
A fan project, Wing Commander: Standoff, is bringing the novel into gameplay using Wing Commander Prophecy's "Vision" engine.