SOLAR SYSTEM

Detailed explanation-1: -John Glenn became perhaps the most famous of the Mercury Seven astronauts, when he became the first American to orbit the Earth. (Yuri Gagarin was also the first person to orbit the Earth during his historic 1961 flight.)

Detailed explanation-2: -Alan Shepard Jr., a Navy Commander and one of NASA’s first seven astronauts, became the first American to travel into space on May 5, 1961. Watch the video above to learn more.

Detailed explanation-3: -The Soviets next kept a cosmonaut in space for a full day. On Feb. 20, 1962, astronaut John H. Glenn became the first American to orbit the Earth during the three-orbit Mercury-Atlas 6 mission, aboard the spacecraft he named Friendship 7.

Detailed explanation-4: -On May 5, 1961, astronaut Alan Shepard became the first American-and the second man-to travel in space when he launched a 15-minute, sub-orbital flight aboard NASA’s Mercury spacecraft Freedom 7.

Detailed explanation-5: -Astronauts Frank Borman, James A. Lovell, and William Anders become the first men to orbit the Moon. Flying in Apollo 8, the men perform 10 total lunar orbits and test many of the procedures that will be used in future lunar missions.

Detailed explanation-6: -Astronaut John Glenn enters the Mercury spacecraft, Friendship 7, prior to the launch of Mercury-Atlas 6 (MA-6) on Feb. 20, 1962. The MA-6 mission was the first crewed orbital flight and Glenn became the first American to orbit the Earth during the three-orbit, five-hour MA-6 mission.

Detailed explanation-7: -Alan Shepard’s flight on Freedom 7 in 1961 was very brief. He did not orbit the earth at all, but instead descended immediately after reaching the flight apex and splashed down only about 300 miles east of the launch site.