NOVA

This NASA Scientist Helps Prevent Mars from Contamination

The spacecraft has to be extremely clean. The entire spacecraft—that includes the rover, the heat shield, the descent stage, and back shell—must contain less than 500,000 bacterial endospores, or spores. Just to give you an idea, a teaspoon of seawater has ten times more bacteria.

Episode 2

4m 58s

WETA Passport

Stream tens of thousands of hours of your PBS and local favorites with WETA Passport whenever and wherever you want. Catch up on a single episode or binge-watch full seasons before they air on TV.