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 glitch cut the main engine a second early, nearly dooming the mission. The aftermath includes Eisenhower’s calm response and the freedom-of-space precedent it secured, Pravda burying the story before Khrushchev weaponized it, the missile gap, the creation of ARPA and NASA, the National Defense Education Act, and the Johns Hopkins physicists whose Doppler tracking led to the Navy’s Transit system and eventually GPS.

• Why an ICBM built for heavy hydrogen bombs had enough thrust to reach orbit
• Specific impulse explained as gas mileage for rocket engines
• The 20 and 40 megahertz frequencies chosen so ham radio operators worldwide could verify the launch
• How Sputnik’s overflight of US territory gave Eisenhower a legal loophole for spy satellites
• From beatnik to GPS: the linguistic and technological ripple effects of 1,440 orbits