Willy Ley

gravity well n.	[1951 W. Ley Letter in Astounding Science Fiction May 154/1 In other words the sun will furnish power only for moving in its own gravitational ‘well’.]
ringwall n.	1944 W. Ley Moon Mysteries in Astounding Science-Fiction Dec. 115/2 The second and in certain respects most puzzling type are the numerous ringwalls or craters which range all the way from gigantic ‘walled plains’—of which Clavius is a fine example—to ‘normal’ Moon craters like Copernicus, and small ‘craterlets’ to tiny ‘beads’.
ringwall n.	1942 W. Ley Luna—Goddess of Love in Amazing Stories May 259/1 When the newly invented telescope was then directed at the moon and astronomers saw the ringwalls for the first time they felt convinced that these circular walls were artificial—nothing natural on Earth looked like them—visible signs of the activity of the Selenites that might, after all, be less lazy and more human than Kepler had imagined. They took the walls to be immense fortifications, built to protect cities.
super-weapon n.	1940 ‘R. Willey’ Fog in Astounding Science Fiction Dec. 86/1 Even if there were a superweapon that would help the remnants of one army to defeat the remnants of all others, the country that got the plans could not manufacture that weapon.