The first pictures of the Earth were taken from an altitude of 105 km.
It was the first US rocket that reached the edge of space.
First time dogs were sent to space.
First intercontinental Ballistic Missile (ICBM) developed.
First animal (dog named Laika) sent to the orbit.
First artificial satellite. successful 1440 orbits around Earth itself which equals to a length of 70 million km (43 million mi).
First photograph of Earth taken from the orbit (by NASA).
First manned flight carrying Yuri Gagarin