Korolev's story is one of the strangest in the history of science. In the late 1930s, during Stalin's purges, he was arrested and sent to the Gulag, at one point working as a prisoner in a design bureau behind bars. He survived, and after the war he rose to lead the Soviet rocket and space program. It was Korolev who drove the Sputnik project in 1957, launching the first artificial satellite and stunning the world; it was his design bureau that sent Yuri Gagarin into orbit aboard Vostok in 1961. Yet through triumph after triumph, his name was kept hidden for fear that Western agents might target him. He was chief engineer of the program from the late 1950s until his sudden death in 1966, and only then was the world finally told who the Chief Designer had been.

The museum grew outward from a single house. In 1970, the modest home in which Korolev was born was dedicated as a memorial, at first a branch of the Zhytomyr Regional Museum. It gained independent standing in 1987, and the present, larger museum building was constructed in 1991, just as Ukraine stepped into independence. What had begun as a preserved childhood home became one of the country's great temples to spaceflight. Since 2013 alone, some 2.5 million visitors have walked through its doors, drawn by a collection of around 11,000 exhibits tracing the whole arc of rocket and space exploration, from early missiles to interplanetary probes.

The centerpieces are not models but the real thing, or close to it. The museum holds the actual descent module of Soyuz 27, the scorched capsule that carried cosmonauts back through the atmosphere, along with its couch and even its launch key. Nearby sit a full-size replica of a complete Soyuz spacecraft and a copy of the Vostok 1 descent module, twin to the craft that first carried a human being into space. Visitors can see a Lunokhod 2 lunar rover, one of the remotely driven machines that trundled across the Moon's surface. And in a small case, easy to miss, rests a sample of genuine lunar soil, brought back automatically by Soviet probes, a few precious grams of another world.

Beyond the crewed spacecraft, the museum tells the story of the Soviet reach into the solar system. There is a model of Venera-7, the apparatus that on 15 December 1970 became the first working spacecraft to land on another planet, transmitting from the crushing, furnace-hot surface of Venus. There are exhibits from the Vega missions that touched down on Venus and studied a comet, and tracings of the trajectories flown toward Mars and its moon Phobos. A model of the giant N1 rocket, the Soviet answer to the Saturn V, stands as a reminder of the Moon race that never quite ended in a Soviet landing. The collection even reaches into the future of the place it honors, marking Leonid Kadenyuk, the first Ukrainian citizen to fly in space, aboard a NASA shuttle mission. It is a fitting arc, from a secret genius born in Zhytomyr to a Ukrainian riding an American spacecraft, all under one roof.