Sputnik 1 was the first artificial Earth satellite. It was a 585 mm diameter shiny metal sphere, with four external radio antennae to broadcast radio pulses. This frightened the Americans into thinking that the Soviets would eventually get nuclear missiles into space and use them on the U.S.
On January 31st, 1958 the U.S launched Explorer I. It was our response the the Soviets Sputnik Satellite.
Weather satellites are used to monitor the weather and climate of Earth. The first satellite was called the Vanguard 2, it was made to measure cloud cover but didn't collect much evidence.
The Explorer 6 was launched this day to study different rays, it also carried a camera to take pictures of Earth while in orbit. The mission lasted 60 days.
The Luna 2 was the second space probe launched to the moon but the first to make it to the moon. It impacted the lunar surface east of Mare Serenitatis near the Aristides, Archimedes, and Autolycus craters.
Yuri Gagarin was a Soviet pilot and cosmonaut. He was the first human to make it into outer space, he becam an international celebrity when he came back and received numerous awards and medals.
Valentina Tereshkova is the first woman to go into space, she was selected from more then 400 applications to pilot Vostok 6, the ship they used.
The Venera 7 was the first probe to land on Venus, it was built really strong and sturdy because Venus' atmospheric pressure was so big, Venera 7 malfunctioned a little but still brought some information back to Earth.
Neil Armstrong was an American astronaut and the first person to walk on the moon. He piloted Gemini 8 in 1966 and performed the first space docking with two ships. Armstrong made it to the moon in Apollo 11, he spent two and a half hours exploring it.
The first space station ever to be launched into space was the Salyut 1. Salyut 1 was in space for about 174 days, the Soviets tried to board it two times before they finally made it on the station.