Following is a transcript of the video. Narrator: If you look at Iron Man's first suit, the Mark 1, and compare it to the hero's nanotech suit from "Avengers: Endgame," a lot has changed.

There's something about the idea of a suit, the jacket matchy-matched with ... It's very, very competitive." Evolution, not a dramatic switch in direction, is what has kept the company going.

This story appears in the July 2019 issue of National Geographic magazine. Space suits—designed to provide oxygen and consistent atmospheric pressure—have evolved from pressure suits for ...