This is a fan-made timeline to extrapolate what happened long before "Valerian: The city of a thousand planets".
1912: British ship Titanic is set for transatlantic voyage. Before that the ship's second officer David Blair was removed from the rooster, but he managed to hand the key to the locker containing a binocular to his replacement. This would help Titanic to avoid icebergs and arrive New York safely.
1924: After the death of Lenin, Leon Trotsky attended his funeral in time, foiling one of Stalin's scheme to wrestle power from him, although he would be assasinated by one of Stalin's henchman, causing the Uncle Joe to seize the political power.
1939: Johann Georg Elser wounded Hitler in an assasination attempt.
1945: Anthony Marchione was shot down by part of the Imperial Japanese air force, causing General Mcarthur to interpret this as an act of non-surrender. Small skirmishes between US and Japanese forces ensued but it was quickly brought to a resolution fortunately.
October 4, 1957: USSR launched Sputnik 1 into space, which is the first artificial satellite.
December 6, 1957: USA launched the Vanguard 1 satellite into orbit.
October 11, 1958: NASA's spacecraft Pioneer 1 is launched. After flying by the moon instead of orbit insertion as planned, the space probe became the first man made object to enter interplanetary space.
1959: USSR's Luna 1 followed Pioneer 1's footsteps.
January 1961: The U.S. launched the first hominid "Ham" into space.
March 1961: NASA astronaut Alan Shepard is the first man in space, with a suborbital flight of the Freedom 7 space capsule.
April 1961: USSR's Yuri Gagarin became the first man to go into orbit.
July 22, 1962: U.S. spacecraft Mariner 1 is launched as the first successful mission to flyby a planet. It will return first images of the planet Venus.
August 27, 1962: Mariner 2 is launched as a successor of the Mariner 1 mission.
1965: Cosmonaut Alexei Leonov made the first spacewalk.
1966: In this TL the X-20 program is not cancelled. As such USAF astronaut James Wood flew the maiden flight of the orbital spaceplane.
1968: NASA's Apollo 8 made the first manned circumlunar flight.
July 1969: NASA astronaut Neil Armstrong is the first man on the Moon.
1971: USSR sent Alexei Leonov to the Moon.
1973: Launch of NASA's Skylab the world's first space station. Meanwhile China launched Fang Guojun their first man in space in this TL in Shuguang-1 mission , though there will be a long hiatus after this due to the chaos of the Cultural Revolution.
1975: The Apollo-Soyuz test mission. Afterwards Russia's Salyut space station docks with Skylab forming what will later become the International Space Station.
1976: NASA's Skylab B artificial gravity space station is launched, which is based on the Self-Deploying Space Station design.
1977: USSR launched their first spaceplane MiG-105 with Gherman Titov piloting the inaugural flight.
1981: Inaugural flight of Columbia space shuttle.
1982: The British began to develop the HOTOL spaceplane with the Americans.
1986: U.S. President Reagan called for "a new Orient Express that could, by the end of the next decade, take off from Dulles Airport, accelerate up to 25 times the speed of sound, attaining low earth orbit or flying to Tokyo within two hours." USSR adds MIR space station into ISS.
1988: USA added the Freedom space station into ISS.
1989: USA's Reusable Orbital Carrier spaceplane went into operation.
1990: The construction of the first Von-Braun wheel station on the ISS is started.
1991: USSR collapses, meanwhile the HOTOL spaceplane is operational.
1995: European Space Agency attach their first modules into the ISS.
1998: The construction of second Von-Braun wheel station onto ISS commences.
2001: An European Hermes spacecraft docks with the ISS.
2002: The first von Braun artificial gravity station is built onto the ISS.
2003: Europa Orbiter is sent to the namesake Jovian moon with the aid of a Space Shuttle. Concurrently NASA launched Deep Space 4 to comet Tempel 1. China returns to space by sending Yang Liwei into orbit.
2004: The construction of third Von-Braun wheel station onto ISS commences.
2008: European Space Agency launched their first ATV unmanned resupply spacecraft to the ISS.
2010: Russia adds Mir-2 into ISS.
2011: China launches Tiangong-1 their first space station.
2012: Both second and third von-Braun stations are built.
2013: The construction of fourth Von-Braun wheel station onto ISS commences.
2015: ESA added several ATV-based modules into the ISS.
2016: Hillary Clinton won the U.S. presidential election. China launches Tiangong-2.
2018: A reformist leader comes into power in China.
2020: China launched a Shenzhou spacecraft to ISS. Afterwards they added several modules into it.
2025: A pathway to generate artificial gravity by electromagnetic force is discovered.
2030: NASA sent the humanity's first expedition to Mars.
2031: By this time the electromagnetic gravity generator is added into the ISS.
2080: All nations have at least one citizen who had visited the ISS.
2150: Humanity first contact with extraterrestrials occured aboard ISS (now called Alpha Station).
2400: The Alpha Station has became too big to stay in Earth orbit. Consequently it has been moved into an interstellar trajectory.