What is a payload specialist?

Payload specialists are experts selected to manage and operate specific scientific or technical equipment on space missions, often aboard spacecraft such as the Space Shuttle or International Space Station. They are typically responsible for the preparation, execution, and monitoring of experiments or cargo during a mission. Payload specialists can come from scientific, engineering, or industry backgrounds and are chosen for their expertise related to the mission's payload. Their role is distinct from that of career astronauts, as they focus primarily on the payload rather than the overall operation of the spacecraft.