 What is the Jupiter weapon?
50 THE JUPITER WEAPON By CHARLES L. FONTENAY The transparent dome of Jupiter's View was faintly visible in the reflected night lights of the colonial city, but the lights were overwhelmed by the giant, vari-colored disc of Jupiter itself, riding high in the sky. “No one has ever landed on Jupiter. But his ship was drawn into Jupiter and lost.” “It was drawn into Jupiter, but he landed it successfully,” said Quest. I was born and brought up there, and I was finally able to build a small rocket with a powerful enough drive to clear the planet.” “If Dr. Mansard succeeded in landing on Jupiter, why didn't anyone ever hear from him again?” she demanded.
 The Jupiter weapon is Quest himself.
 Asrange is the Jupiter weapon.  The surgiscope is the Jupiter weapon.  No one knows what the Jupiter weapon is, but the plans are in Dr. Mansard's notes.  The Jupiter weapon is Quest himself.