I mostly know Czech authors by name. Some are probably not translated to english:

Karel Čapek (pre soviet)

František_Běhounek (part of Italia north pole expedition) https://en.wikipedia.org/wiki/Franti%C5%A1ek_B%C4%9Bhounek

J. M. Troska https://translate.google.com/translate?sl=auto&tl=en&js=y&pr...

Ondřej Neff (post soviet) and his stories around Clarkes monoliths.