A robotic probe reaches another planet

Sputnik 1 began transmitting radio beeps as it orbited Earth, opening new possibilities for tracking a satellite.

Radio signals from Sputnik could be received outside the launch program, making the orbit publicly observable.

The successful launch created a new platform for studying Earth and, later, the wider universe.

The spacecraft became the first successful interplanetary probe to visit another planet.

Mariner 2 measured properties of the planet while passing it without entering orbit.

The flyby provided direct data to compare with Earth-based astronomical observations.

Valentina Tereshkova became the first woman to travel in space.

The Vostok 6 mission began from Soviet Central Asia and went on to orbit Earth 48 times.

Tereshkova’s launch showed a woman could perform an orbital spaceflight despite earlier exclusion.

The spacecraft put Tereshkova in Earth orbit for a mission lasting nearly three days.