CE April 12, 1961, Soviet Yuri ?? Alexievich?? Gagarin flew into space aboard the Vostok 1 spacecraft, ushering in a new era of space exploration by humans on Earth. Pen "Fun" Pavilion www.biquge.info

On April 19, 1971, the Soviet Union's Salyut 1 was launched, becoming the first space station in the history of human beings on Earth that could allow humans to stay in space for a long time.

In 1993, the design of the International Space Station (international_spacestation, ISS) was completed and put into operation with the participation of 16 countries.

In December 2011, after 19 years, the construction of ISS was completed, and the human beings on earth further entered the cosmic age.

In 2035, Space City A will be completed at the Earth-Moon Lagrange point L4 and welcome the first space immigrants of human beings on Earth. Five years later β Space City was built at the Earth-Moon Lagrange point L5. These two space cities at the symmetrical Lagrange point are collectively known as the Twin Cities. (Regarding L4 and L5, in all binary systems, there are 5 Lagrangian points, of which L1-L3 on the central axis are unstable points, and L4 and L5 at 60 degrees on both sides of the binary star are stable positions, which can basically maintain their attitude for a long time without dynamic compensation.) ）

CE 2076, based on the Mexican physicist Mingo?? Alcubelli () proposed the curvature-driven theory in 1994, after nearly a century of hard work by human beings on earth, the first curvature engine was born, and sub-light speed flight became a reality. The solar system, with a radius of 50 astronomical units (the average distance from the Earth to the Sun, about 500 light-seconds per astronomical unit), has truly become the circle of human life.

In the years that followed, a series of space cities were established one after another, such as Earth-Sun, Fire-Sun, Wood-Sun, and Wood-Io. Even so, the solar system is still like a huge cage, restricting humanity from going further into the universe. The closest star to the solar system, Centauri A, commonly known as Proxima Centauri, would take more than four years to reach even with curvature engines, making manned voyages impossible in terms of supplies, communications and time.

In 2081, the Visitor, an unmanned spacecraft with a curvature engine, set sail for Centauri A C, becoming the first spacecraft in Earth's human history to fly out of the solar system. (Various conventional spacecraft launched previously, such as the American Voyager series, have not been acknowledged.) In contrast to the visitors who flew to the edge of the solar system in the narrow sense of the word, Voyager 1 and 2 with conventional engines took 36 and 33 years, respectively, and never flew out of the broad solar system, the heliosphere with a radius of about 200 AU, before losing contact. Not to mention that in the cosmic era, the extent of the solar system in the administrative sense reached 2 light years. Even if we believe that the Voyager series of ships were undamaged and did their duty, they would have been overtaken by the 36th hour of the Visitor's flight. Forty-eight hours after takeoff, the Visitor successfully passed through the heliosphere, leaving the heliosphere and entering interstellar space. ）

(Author's note: Whether from a practical or science fiction perspective, I don't think the American Voyager 1 and 2 will be the first human vehicles to leave the solar system.) As a product of the Cold War between the two superpowers in the '70s, these two spacecraft have far more political significance than practical use, and are the first vehicles to leave the solar system that Americans boast about. According to the Americans themselves, both spacecraft will lose power in 2025, stop the operation of various instruments, and become cosmic junk that relies on inertial flight. At this time, they are still traveling long distances in the heliosphere, at least half a century from the edge of the heliosphere. Even if they do fly out of the heliosphere after a hundred years, they will fly out as cosmic garbage. And I believe that at that time, human technology must have broken away from some kind of shackles, and it was not a problem for new aircraft to surpass the Voyager, so I rejected them first. ）

In 2099, the first jump engine based on superstring theory was born, using shuttle wormholes to break through the speed of light, and human beings on earth truly entered the cosmic age. The Common Era, which has been in use for more than 2,000 years, was thus restructured into the String Era.

SC (string_century) string era

In SC0001, the first manned spacecraft using the jump engine, the Columbus, arrived in an unknown extragalactic galaxy through a jump flight, and the galaxy was calculated to be located in the direction of the Earth's starry sky in the constellation Virgo, and it was named the New American Galaxy. In the following years, human beings on Earth have entered new Asia, new Europe, new Africa and other extragalactic galaxies, and branched out in the universe.

In SC0013, with the discovery of the radioactive element UBH-310 of the Stable Island in the giant molecular cloud of extragalactic galaxies (note: this is a stable isotope of element 126 calculated based on Mendeleev's periodic table, with a theoretical half-life of more than 1 million years, so the author hypothesizes that it should be found in the giant molecular cloud at the beginning of star evolution), the second generation of curvature engines was born, reaching a cruising speed of 8 times the speed of light, which is close to the theoretical upper limit of the curvature flight speed.

The second generation of curvature engines has made interstellar travel normalized. In the same year, the Visitor2 manned spacecraft set off for Centauri A C, a seven-month journey.

In SC0037, with the deepening of the understanding of the universe, the new European galaxy discovered the Ray Particle (reject_particle), commonly known as the R particle. R particles are a kind of heavy particles, which have a strong interference effect on various elementary particles, and are widely used in the military field once discovered, whether as a particle beam weapon or for communication jamming. As long as a certain concentration of R particles is dispersed in space, electromagnetic particles can be completely blocked, and communication can be neutralized. Moreover, even photons produce a certain degree of random polarization, causing visual bias on objects one lightsecond away. If it is not too high a concentration of R particles, it will be harmful to the human body, and even photoblocking can be achieved in space.

In SC0041, as the birthplace of human beings on Earth, the backward political system of the solar system is seriously lagging behind the cosmic age. There are still hundreds of countries and regions on the earth in the land of projectiles, and there are constant disputes. Against this backdrop, the careerists of the interstellar settlers issued the Declaration of Independence for the Cosmic Age in New America, declaring their independence from the jurisdiction of the Earth countries and establishing the New American Federation.

Due to the communication constraints of the R particles, the United Nations peacekeeping forces sent by the countries of the earth to clean up the "rebellious" are like blind and deaf people in the New American system, and they are quickly defeated.

After witnessing the victory of the New Americas, the colonial galaxies declared their independence, the new Asian Republic, the new European Union, and even the new African kingdoms that implemented the imperial system.

It was only at this time that the earth humans who stayed in the solar system realized that in the face of the rich resource reserves of the immigrant galaxy, they had become the weakest party, and after hundreds of meetings for half a year, the Earth Federation was announced, and the earth, which had abandoned the boundaries of the country, finally achieved great unification for the first time.

At this time, the Earth Federation was already quite barren, and the planets of the solar system were almost scarce in resources, and there were immigrant galaxies in the past, and now they can only rely on accelerating the development of other star systems in the Orion Arm of the Milky Way. Fortunately, the colonial galaxies after independence did not look down on the resource-poor solar system, and they were at peace with each other.

However, with the advancement of cosmic colonization, humans on Earth have gradually discovered very few terrestrial planets suitable for human habitation, and it is difficult to find a terrestrial planet in most star systems. Most of the planets are mineral stars, and they don't even qualify as agricultural stars, let alone be inhabited by humans.

The earliest terrestrial humans to arrive in extragalactic galaxies all built space cities on the Lagrange point of mineral stars, and they worked hard to find a terrestrial planet because of the difference in atmospheric composition, which could only be used as an agricultural star first, and then according to the respective conditions of these planets, it was expected that tens of days, hundreds or even thousands of years of environmental transformation would be carried out.

In SC0052, the second generation of the jump engine combined with curvature technology was born. Compared to the first-generation jump engine, which could only rely on natural wormholes to follow the current, the second-generation engine can perform a single directional jump of up to 1000 astronomical units, requiring no less than an hour of cooling and recharging time between each jump, which is equivalent to 17 times the speed of ordinary curvature.

The second-generation engines have further accelerated interstellar movements, shortening the journey from Earth to Centauri A C to half a month. As a result, humanity has temporarily slowed down the first type of transition full of unknown dangers, and stepped up the exploration of the surrounding star systems, and the colonized galaxies have entered a period of great development within the galaxy.

(The way in which the first-generation jump engine uses natural wormholes to make jumps is called a type 1 jump.) At the beginning of the SC era, more than 90% of ships that used Category 1 flight for exploration were lost in space, destroyed, or never heard from. As of SC0052, humans on Earth only have four major extragalactic galaxies, led by New America, and these four galaxies all have fixed natural wormholes to and from the solar system. Therefore, the solar system is also called the "human hub" by the extragalactic immigrants, and the communication between extragalactic galaxies needs to be carried out through the transit of the solar system. ）

With the use of second-generation engines and the study of the spectrum of the main sequence zone (on the Harrow diagram that reveals the spectrum of the evolution process of stars, the distribution of stars is regular, and one of the distribution regions located in the diagonal of the coordinate system belongs to the main sequence zone, and the Sun is a typical main sequence star in the main sequence zone), the space exploration work has become more targeted. There is evidence that main-sequence stars with masses close to the Sun are most likely to find terrestrial planets.

In the years that followed, several habitable planets were discovered, and a significant number of colonized galacies were able to say goodbye to space life and return to Earth.

In SC0073, there are a total of seven habitable planets on Earth, including Earth.

New America has only one habitable planet, which serves as its capital planet and is named "Dream of the Americas".

New Asia has two habitable planets, called "Tianjing" and "Dijing", and the living environment of Dijing is actually not good, just barely able to live in people, and it is expected that it will take decades of long transformation before the situation will slowly improve.

In contrast, the luck of the new European galaxy is not very good, and it has not yet found any planets that can be minimally inhabited, and can only tentatively designate an agricultural star "Red Sea" as the capital star, and build a large biosphere city to fill the façade.

What is enviable is the New African Kingdom, which found three habitable planets in one go, namely "Cape of Good Hope", "Kilimanjaro" and "Sahara".

In SC0074, the year after the discovery of the Sahara Star in New Africa, based on the imbalance of planetary resources, new contradictions could not be concealed soon, and with the instigation and assistance of New America, under the slogan of "freedom, democracy, and liberation", the new European Union launched a military operation against the New African Kingdom "Sahara Liberation War".

In SC0075, New Asia and the Earth Federation were drawn into this war. In this so-called war between five planets against two planets, it is actually the resource-rich New Asia and the New African Union that are on the weak side. The New Americas, the New European Union, and the Earth Federation are engaged in wars of aggression under the banner of ideology.

In SC0076, the third habitable planet of the New African Kingdom, the Sahara, fell, and this enclave became the capital star of the new European Union, and was renamed "Eurostar".

In SC0078, the second habitable planet of the New Asian Republic, Dijing, fell and became a territory of the New American Federation. In the years that followed, the new Asians rose up to resist, causing the new Americas, unwilling to get bogged down, to shift the focus of their operations to New Africa.

In SC0079, Kilimanjaro, the second most habitable planet of the New African Kingdom, fell and became a new colony of the Earth Federation.

On June 13, SC0081, Feng Yu was born in the new Asian galaxy Tianjing Star Field, Landanum Deonos, L4 Space City. (Planet 7 of the Tianjing System is a mineral star rich in lanthanides, named Lanthanum by New Asia.) Lanthanides are commonly known as rare earths. ）

In SC0083, the combined forces of the New Americas, the New European Union, and the Earth Federation captured the Cape of Good Hope, the capital of the New African Kingdom.

The new African kingdom was destroyed, and part of the original kingdom army surrendered, some went underground and became a rebel army, and the other part became a pirate army in the cosmic age, led by various warlords, and plundered under the banner of revenge.

In the same year, the New American Federation tore up its alliance with the New European Union on the grounds that Dijing was barren, monopolized the Cape of Good Hope, and became a superpower with three habitable planets, and changed its name to the UAC Federation (United Of_America_Dream_and_Cape_of_good_Hope, abbreviated as UAC).

In SC0084, the mediation between the two sides failed, the new European Union declared war on the UAC Federation, the Earth Federation with two habitable planets declared neutrality, and the New Asian Republic began the "Dijing Counteroffensive".

In SC0091, a new type of individual space combat weapon, mobile suits, appeared, and gradually replaced traditional air and space fighters as the mainstream force of space warfare. Compared to the air and space fighters, which are limited in attack and movement, mobile suits are more suitable for all-round space combat.

The first Mobile Suit was born in the UAC Federation, codenamed Mobile Suit MS (mobile_soldier), with humanoid combat armor and vector jets installed in all joints of the body, which can adapt to all-round space movement, equipped with particle beam rifles and alloy sabers. In the ensuing war, the applicability of the humanoid mobile suit was questioned to a certain extent, and its high cost and high requirements for the individual ability of the pilot made it impossible to install it on a large scale.

In SC0092, the New Asian Republic introduced a more applicable spherical mobile suit B (ball), commonly known as the iron ball. The Iron Ball does away with the complex anthropomorphic joints of the Mobile Suit MS, and only retains two multi-axis robotic arms to temporarily carry various devices or weapons, and the weapon also eliminates the more difficult to operate alloy sabers, and mounts the particle beam rifle on a turntable above the head of the body.

The advent of the cheap and easy-to-handle iron ball has made mobile suits truly popular, allowing pilots to re-familiarize themselves with the dashboard and recruit with no piloting experience to get up to speed. At the same time, the humanoid mobile suit has not been eliminated as a result, but has been further enhanced as a high-end mech. Mobile Suit pilots are also polarized due to differences in their bodies, and are divided into general pilots who lack talent and pilots who drive humanoid mobile suits.

In SC0097, 16-year-old Fengyu joined the New Asian Republic Space Force and became a pilot of the iron ball. This is where the plot of the book begins.