What was the name of the first artificial satellite in space?

Sputnik 1, launched on 4 October 1957 - an aluminium sphere 58 centimetres across with four aerials and a radio transmitter, and essentially nothing else. It did no science beyond what could be inferred from its signal and its orbit, and it burned up after three months.

The signal was the payload. It broadcast a simple beep on frequencies any amateur could receive, which was a deliberate choice: anyone in the world with a shortwave set could hear the Soviet Union passing overhead every ninety minutes. In the United States the effect was closer to panic than admiration, and it produced NASA, the Advanced Research Projects Agency - which later built the network that became the internet - and a wholesale reform of American science teaching.

It also settled a legal question by simply doing it. Sputnik passed over every country on Earth without asking, and nobody protested, which quietly established that orbital space is not national territory - a principle later written into the Outer Space Treaty. The launch also drew the first line under the space age's least comfortable fact: the rocket that put it up was designed to deliver a warhead.