Laika - first animal in space, Sputnik II, 1957

G. Dobrovolskiy, V. Volkov, V. Patsaev - crew of the ill-fated Soyuz 11. After 24 days in space as the first crew of Salyut 1, they died on reentry when a valve opened prematurely, venting the atmosphere. They were not wearing spacesuits.

Sergei Korolev - the father of the Soviet space program. Known as the "Chief Designer" and only declassified after his death, he was responsible for the Soviet Union's early space firsts, including SPutnik, Vostok, Voskhod, and the design of the Soviet L-1/L-3 lunar program, which included the N-1 "super rocket" and the Soyuz program. He died in 1966 after surgery. (I know you didn't have that there, but I mixed him up with Komarov at first.)

Vladimir Komarov - pilot of Soyuz 1, he died in 1967 as his capsule crashed to the ground at over 500 mph because his parachutes twisted and failed. He had been spinning out of control since his fifteenth orbit, and may have blacked out or died during the rough reentry.

What is the Nedelin disaster (92) and Vostok accident of 1980 (50) plus myriad other accidents? - rocket explosions on the ground

:roll: Now that I look over your post, I see you were answering in a Jeopardy form instead of asking what they were. Oops. :roll: Oh well.