Dog ejector seat and suit as used to Soviet suborbital rocket flights, c. 1955. (Photo: © The open joint-stock company ‘Research, Developement & production Enterprise “Zvezda”/ State Museum and Exhibition Centre ROSIZO/Courtesy Science Museum London)

In 1957, the Soviet space program launched the world’s first satellite, Sputnik 1. Later that year Laika the dog became the first animal to orbit the earth, quickly followed by the first humans, Yuri Gagarin and Valentina Tereshkova, in 1961 and 1963.

These are just some of the pioneering achievements by Soviet space program, which began in the 1930s and ended with the dissolution of the USSR in 1991. Much of the program was classified until the 1980s, which makes the new exhibition at London’s Science Museum, “Cosmonauts: The Birth of the Space Age,” all the more fascinating.

In collaboration with the State Museum Exhibition Centre ROSIZO and the Federal Space Agency, Roscosmos, the exhibition contains the largest collection of Soviet spacecraft and artifacts ever exhibited outside of Russia. Noteworthy artifacts include the 1955 engineering model for a dog ejector seat and suit, and the Vostok-6 descent module used by Tereshkova, charred from re-entry into the earth’s atmosphere.

Below are some of the highlights of the exhibition, which opens on September 18, 2015.

“The fairy tale became truth”: a 1961 poster by Boris Staris celebrating the pioneering mission of Yuri Gagarin. (Photo: Memorial Museum of Cosmonautics/ © unknown/ Courtesy Science Museum London)

A poster from 1959 by Iraklii Toidze “In the name of peace”, celebrating one of the luna missions. (Photo: The Memorial Museum of Cosmonautics/© unknown/Courtesy Science Museum London)

Yuri Gagarin before the first space flight, 12 April, 1961. (Photo: © RIA Novosti/Courtesy Science Museum London)

The first Soviet cosmonaut squad, c. 1961. Three thousand cosmonaut candidates were whitteld down to a first team of twenty. (Photo: © RIA Novosti/Courtesy Science Museum London)

A Vostok VZA ejection seat (engineering model) and SK Suit as used on Vostoks 1-6, from 1961 to 1963. (Photo: © The open joint-stock company ‘Research, Developement & production Enterprise “Zvezda”/ State Museum and Exhibition Centre ROSIZO/Courtesy Science Museum London)

The 1963 Vostok-6 descent module in which Valentina Tereshkova flew into space Much of the brown-colored heat shield is charred from the 27,000km/hr descent back to Earth. (Photo: (Photo: © The open joint-stock company ‘Rocket and Space Corporation Energia after SP Korolev’/ State Museum and Exhibition Centre ROSIZO/Courtesy Science Museum London)

The five-metre tall Lunnyi Korabl or LK-3 luna lander from 1969, designed to take a single cosmonaut to the Moon’s surface. The Soviet manned Moon programme was kept secret until 1989, and the LK-3 is the most complete lander of its kind in existence today. (Photo: The Moscow Aviation Institute/State Museum and Exhibition Center ROSIZO/Courtesy Science Museum London)

The Lunokhod-2 lunar roving vehicle from 1973. The Soviet Union successfully launched two Lunokhod vehicles on the Moon, which were operated remotely from Earth. (Photo: © State Museum and Exhibition Centre ROSIZO/Courtesy Science Museum London)

Chibis (Lapwing) Lower Body Negative Pressure Suite, 1971-present. This suit helps prepare cosmonauts to return to Earth and the conditions of normal gravity, by using a vacuum effect to draw the blood towards the legs. (Photo: © The Memorial Museum of Cosmonautics/State Museum and Exhibition Centre ROSIZO)

MIR space station shower, c. 1990. This shower used a stream of air to pull the water over the bather. (Photo: © The open joint-stock company ‘Research, Developement & production Enterprise “Zvezda”/ State Museum and Exhibition Centre ROSIZO/Courtesy Science Museum London)

SOKOL space suit manufactured by Zvezda and worn by Helen Sharman, Britain’s first cosmonaut, in 1991. (Photo: © Science Museum/SSPL)

The surrogate cosmonaut, Tissue-Equivalent Phantom Mannequin, which was flown around the Moon on Zond-7 in 1969 to test the effects of cosmic radiation on living tissue. Its face was made in the image of Yuri Gagarin. (Photo: © The Polytechnic Museum/State Museum and Exhibition Centre ROSIZO)

Alexei Leonov self-portrait after his 1965 space walk ‘Over the Black Sea’, painted in 1973. (Photo: © The Memorial Museum of Cosmonautics)