Astounding Science Fiction May 1951 (Volume 47, Number 3)
Illustrations by Ed Cartier, Paul Orban, Hubert Rogers. Cover by Hubert Rogers (for "Galactic Gadgeteers.")

Novelettes: "Galactic Gadgeteers" by Harry Stine
"Izzard and the Membrane" by Walter M. Miller, Jr.

Stories: "Success Story" by Julian Chain
"Guess Again" by J. A. Meyer
"Key Decision" by H. B. Fyfe.

Science: "Clipper Ships of Space" by Russell Saunders,
"The Argonne Heavy Water Reactor" (reprint of news release of Atomic Energy Commission.)

John W. Campbell's editorial is "Conservatism"; Book reviews by P. Schuyler Miller.