In 1946, he led the Vystral group, which performed test flights of V-2 rockets at the Soviet missile institute in Nordhausen, Germany.

[1] During his tenure at OKB-1, the bureau achieved several significant achievements in rocketry and space flight, such as the engine used for the first intercontinental ballistic missile, the R-7 Semyorka, the first spacecraft in orbit, Sputnik, and the first crewed orbital space flight, Vostok 1.

Due to the secrecy surrounding the Soviet space program at the time, he was only identified in the press as "a scholar in the field of the elaboration and testing models of new machinery.

In Rockets and People, scientist and historian Boris Chertok recounted how Voskresensky reacted when a missile being tested developed a leak of a supposedly radioactive substance.

Author Matthew Brzezinski documented an unusual technique that Voskresensky developed for fixing some issues with the R-9 missile:Korolev's head of testing, the equally crotchety Leonid Voskresensky — the only person among the thousands of NII-88 and OKB-1 employees permitted to address Sergei Korolev by his first name, without the formal patronymic — had a decidedly low-tech method for dealing with leaks.