An illustration of NASA’s Perseverance rover landing on Mars. Hundreds of critical events must execute perfectly and exactly on ti...

An illustration of NASA’s Mars Perseverance rover deploying its supersonic parachute from its aeroshell as it slows down before la...

This illustration shows NASA’s Mars Perseverance rover on the surface of the Red Planet.

An illustration of NASA’s Perseverance rover landing on Mars. Hundreds of critical events must execute perfectly and exactly on time for...

An illustration of NASA’s Mars Perseverance rover deploying its supersonic parachute from its aeroshell as it slows down before la...

Will Allen with engineering models of the (clockwise from bottom) Sojourner rover, a Mars Exploration Rover, and Curiosity in JPL's Mars Yard ...

Bill Allen in JPL's Mars Yard in early 2020.

An illustration of NASA’s Perseverance rover landing safely on Mars. Hundreds of critical events must execute perfectly and ...

NASA’s Perseverance rover fires up its descent stage engines as it nears the Martian surface in this illustration.

In this illustration, NASA’s Perseverance rover gets its first look at the Martian surface below, after dropping its heat sh...

NASA’s Perseverance rover deploys a supersonic parachute from its aeroshell as it slows down before landing, in this artist&...

The aeroshell containing NASA’s Perseverance rover guides itself towards the Martian surface as it descends through the atmosphere in th...

In this illustration of its descent to Mars, the spacecraft containing NASA’s Perseverance rover slows down using the drag g...

With its heat shield facing the planet, NASA’s Perseverance rover begins its descent through the Martian atmosphere in this ...

This illustration shows NASA’s Perseverance rover casting off its spacecraft’s cruise stage, minutes before entering t...