Sputnik 1 (/ˈspʌtnɪk, ˈspʊtnɪk/; "Satellite-1", or "PS-1", Простейший Спутник-1 or Prosteyshiy Sputnik-1, "Elementary Satellite 1") was the first artificial Earth satellite. The Soviet Union launched it into an elliptical low Earth orbit on 4 October 1957. It orbited for three weeks before its batteries died and then orbited silently for two months before it fell back into the atmosphere on the 25th December 1957.
At some point it became possible for Soviet spacecraft to run on battery power when in Earth's shadow and recharge the battery when back in sunlight.
- What was the first Soviet spacecraft that could do this?
- Where were the photovoltaic cells made?