He designed and built the rockets that launched the first artificial satellite into space, as well as the first animal, the first man,the first woman, the first two man crew and the first three man crew. And nearly sixty years after his time versions of very same rockets are still being used. 
You'd think that the man responsible for these achievements would be famous, synonymous with genius with all kinds of spacecraft and other cool stuff named after him. And yet Sergei Korolev spent his career working in near anonymity. An enigma who accomplishments remain hidden from public view, until the day his obituary ran in 1966.
A brilliant engineer, Korolev build his first glider at the age of 17 and after graduating from Kiev polytechnic institute in his native Ukraine, he became interested in rocket propulsion.
in 1932 while still in his mid twenties, Korolev was appointed the head of the soviet union's jet propulsion research group, tasked with running the countries rocket development program, but his career came to an abrupt halt in 1938 when he was arrested by Joseph Stalin's secret police on trumped up charges that were probably made by his own colleges. He spent much of the next seven years imprisoned in a Siberian gulag. Upon his release at the end of World War Two Korolev resumed his duties, but in order to keep his identity and his work a secret, he was referred to in official communications only as the chief designer. 
Like their American counterparts, Russians wanted to learn everything about the vastly superior rocket technology developed by the Germans. Specifically the V-2 pioneered by Werner von Braun. 
Most German scientists had surrendered to the Americans, but the soviets captured some of the rocket components and enlisted a few German scientists of their own. With their help Korolev essentially reverse engineered the V-2 and produced a vastly improved version of it. 
The result was the R-1. First launched in 1948, it had a range of 270 km, 70 km farther than the K-2. The next version, the R-2, doubled that range. As Korolev's team lengthened the fuel tanks and improved the propellant turbo pumps designed by von Braun, they replaced the ethyl alcohol fuel with methyl alcohol, in part because the out launch troops had taken to drinking the rocket fuel.
Korolev also added a detachable warhead to the R-2, which had important implications for space flight, because it could be turned into a recoverable payload capsule with a parachute. In fact in 1951 Korolev strapped two dogs into an R-2 payload and recovered them 100 kilometers away.
As military weapons, the R-1 and R-2 never really caught on, mostly because the range was too short, the warhead was too small, and the engines oxidizer, liquid oxygen was extremely tricky and dangerous to use. But Korolev's 7th generation rocket, the R-7 would be the game changer as a weapon, but more so as an instrument of science. Designed to carry a 5,400 kg warhead more than 8,000 km the R-7 was the first intercontinental ballistic missile, and it looked unlike any rocket that had come before it, with a long central core booster surrounded by four detachable liquid rocket boosters, the R-7 was designed to provide a maximum thrust at launch with the ability to shed its empty fuel tanks as it gained altitude and speed.
It's a model often used today, but in 1957 it was a revolutionary concept. R-7 worked, not so much as an ICBM. Its range wasn't quite long enough to scare Americans, but rather as a launch vehicle. In October 1957, while officially stick in the testing phase an R-7 rocket named Sputnik launched a 57 cm satellite of the same name into low-earth orbit. Thanks to Korolev's invention, the space age had begun.
This was just the beginning for Korolev's rocket. Every subsequent Soviet rocket and launch vehicle has used the basic R-7 design. The changes have just involved lengthening the rocket to hold more fuel, allowing it to carry larger pay loads.
In 1961 an adapted version of the R-7, known as Vostok, launched the first human, Yuri Gagarin, into space. Several years later the Soyuz rocket program began, and continues to this day. All in all, variations of the R-7 have been launched into space more that 1700 times.
Every time another one goes up there, we have Sergei Korolev, AKA the chief designer to thank.
Thanks for joining me for SciShow Space. If you want to keep exploring the universe with us check out Subbable.com/SciShow to see how you can become a contributing member of our community. Don't forge to go to youtube.com/scishowspace and subscribe.