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What Was Project Mercury? (Grades K-4)

Project Mercury was a NASA program. It launched the first Americans into space.

Astronauts made six flights during the Mercury project. Two of those went to space and came right back down. Four of them went into orbit and circled Earth. The first of the six flights was in 1961. The last flight was in 1963.

Mercury-Redstone rocket launching
John Glenn became the first American to orbit Earth on the Friendship 7 mission.
Credits: NASA

What Spacecraft Was Used for Project Mercury?

The Mercury capsule was small. It only held one person. The capsule had very little room inside. The astronaut had to stay in his seat.

Two types of rockets were used for Mercury launches. The first two of the six flights with an astronaut on board used a Redstone rocket. The other four manned flights used an Atlas rocket. Both rockets were first built as missiles for the military.

The project was named Mercury after a Roman god who was very fast. Each astronaut named his spacecraft. Alan Shepard included a 7 in the name of his capsule. This was because it was the seventh one made. The other astronauts included a 7 also. This was in honor of the seven astronauts chosen for the project.

Mercury Redstone rocket on launchpad
Alan Shepard’s Freedom 7 capsule was launched on a Redstone rocket.
Credits: NASA

Who Were the Mercury Astronauts?

NASA chose seven astronauts for Project Mercury in 1959. It was one of the first things NASA did. NASA was only six months old.

Alan Shepard made the first Mercury flight. He was the first American in space. He named his spacecraft Freedom 7. The 15-minute flight went into space and came back down. Shepard later walked on the moon during the Apollo 14 mission.

Gus Grissom was the second astronaut to fly in Project Mercury. Grissom named his capsule Liberty Bell 7. The third person to fly was John Glenn. In 1962, he was the first American to orbit Earth. His capsule was Friendship 7.

The second American to orbit Earth was Scott Carpenter. He flew on Aurora 7. Wally Schirra (Shuh-RAH) was next, on Sigma 7. Gordon Cooper flew on the last Mercury mission. He spent 34 hours circling Earth. His capsule was Faith 7.

Deke Slayton was also one of the “Mercury Seven” astronauts. A health problem stopped him from flying a Mercury mission. He flew into space in 1975 on a different mission.

A photo of seven project Mercury astronauts
The seven Mercury astronauts were (from left) Wally Schirra, Alan Shepard, Deke Slayton, Gus Grissom, John Glenn, Gordon Cooper and Scott Carpenter.
Credits: NASA

How Did NASA Make Sure Mercury Was Safe?

Before astronauts flew, NASA had test flights. People were not on these launches. The flights let NASA find and fix problems.

The first Atlas rocket that launched with a Mercury capsule exploded. The first Mercury-Redstone launch only went about four inches off the ground. NASA learned from these problems. NASA learned how to fix them. NASA made the rockets safer.

Three other “astronauts” also helped make Mercury safer. A rhesus monkey, Sam, and two chimpanzees, Ham and Enos, flew in Mercury capsules. Enos even made two orbits around Earth. Since the monkey and the chimpanzees made it back safely, NASA knew it was safe for astronauts.

A photo of Ham the chimpanzee who was safely who safely returned from space
Ham the chimpanzee made his Mercury flight in a special seat.
Credits: NASA

Why Was Project Mercury Important?

NASA learned a lot from Project Mercury. NASA learned how to put people in orbit. It learned how people could live and work in space. NASA learned how to fly a spacecraft. These lessons were very important. NASA used them in later space projects.

After Mercury came the Gemini program. The Gemini spacecraft had room for two astronauts. NASA learned even more with Gemini. Together, Mercury and Gemini prepared NASA for the Apollo program. During Apollo, NASA landed human beings on the moon for the first time.

More about Project Mercury

Project Mercury Overview
Women Who Reach for the Stars (The Mercury 13)

Read What Was Project Mercury? (Grades 5-8)