👾 what they taught me in school was that Sputnik I did nothing but beep and be a propaganda symbol for those evil communists

in reality it was a pressure vessel filled with nitrogen, and a temperature sensor monitored its internal temperature. the duration of the beeps encoded that temperature data so we could deduce the thermal environment of low earth orbit. the shell was thin, and a pressure sensor would have reported via beep if the pressure vessel was punctured, so we would know if low earth orbit was full of dangerous micrometeors. the propagation of radio waves from the satellite allowed us to measure earth's ionosphere, and the atmospheric drag allowed us to measure the density of the upper atmosphere.

the upper stage of the R-7 rocket, which also entered orbit, was used to conduct telemetry experiments, and contained reflective panels making it much more visible than Sputnik I itself, and it was instrumental in tracking the location of the satellite as the difference in drag between the objects was known.

Sputnik I's high inclination orbit allowed it to be observed by all inhabited places on earth during its three months in orbit, and anyone with radio equipment could receive its transmissions

an incredible achievement that paved the way for all future spaceflight projects!