Final answer:
A food scientist works on projects that affect the daily health of astronauts in space, ensuring safe and nutritious meals suitable for the microgravity environment of the ISS.
Step-by-step explanation:
The scientist most likely to work on projects directly influencing the daily health and well-being of an astronaut on the International Space Station (ISS) is a food scientist. Food scientists are critical for ensuring the safety and nutritional adequacy of foods consumed by astronauts in space. With the collaboration of organizations like NASA, they help develop food safety systems such as the Hazard Analysis and Critical Control Point (HACCP), designed to prevent contamination and assure safety from bacteria and toxins. Additionally, food scientists play a key role in addressing the unique challenges presented by the microgravity environment, such as the prevention of loose crumbs that may damage equipment. Their work ensures that astronauts have meals that are not only safe and nutritious but also suitable for consumption under weightless conditions.