The Mercury missions did not land. They were orbital missions meaning the spacecraft circled the Earth and then returned to land on the surface of the Earth via splashdown.

Here's how it worked:

1. Launch: The Mercury capsule was launched atop a powerful rocket.

2. Orbit: The capsule entered orbit around Earth.

3. Re-entry: When it was time to return, the capsule's retrorockets fired, slowing it down and causing it to begin its descent.

4. Splashdown: As the capsule entered the atmosphere, it used a heat shield to protect the astronaut from the intense heat of re-entry. The capsule landed in the ocean, where recovery teams were waiting.

So, instead of a controlled landing on land, the Mercury missions ended with a controlled splashdown in the ocean. This method was chosen for several reasons:

* Safety: It was considered safer than attempting a land landing, especially with the limited technology available at the time.

* Recovery: The vast ocean offered a larger target area for recovery teams, making it easier to locate and retrieve the capsule and the astronaut.

* Testing: Splashdown provided a way to test the capsule's re-entry and landing capabilities.

The Mercury missions were a crucial step in the development of human spaceflight, paving the way for the more complex missions that followed.