The glowing object families watched cross the sky in October 1957 was not Sputnik at all but the discarded 26-meter core stage of its R-7 rocket; the satellite itself was a polished 58-centimeter sphere. This episode follows Sergei Korolev's scramble to beat America's Vanguard program after the 1955 International Geophysical Year announcements, his abandonment of the thousand-kilogram Object D laboratory in favor of the stripped-down elementary satellite, and a brutal string of R-7 test failures before two successes in August and September 1957.

The hosts detail the elegant engineering inside the 83.6-kilogram sphere, where silver-zinc batteries made up 60 percent of the mass and pressurized nitrogen with barometric and thermal switches turned the beep rhythm itself into a sensor for punctures and overheating. On launch day a fuel regulator ...