Retired astronaut Scott Kelly pictured during his #YearInSpace on the International Space Station. Kelly is seen with grapefruits, lemons and oranges during a Twins Study that measured metabolic change in relation to the food he ate during that time. Being able to determine which foods cause what kinds of metabolic changes and how that evolves over time will be very informative to see how what you eat determines what you are chemically. This information could be helpful for researchers creating recommendations to protect the health of astronauts embarking on long-duration missions, such as a Journey to Mars, as well as benefit humans on Earth. Credit: NASA #journeytomars #iss #freshfruit #space #research #instamoment