Tracy C. Dyson was selected as an astronaut by NASA in 1998. The California native has a Ph.D. in Chemistry, and is a veteran of two space flights. Dr. Dyson has designed, constructed and implemented electronics and hardware for the study of atmospheric gas phase chemistry, and has developed and presented numerous papers on methods of chemical ionization for the spectral interpretation of trace compounds. In 2007, Dyson flew aboard the Space Shuttle Endeavor on STS-118, where she served as a Mission Specialist. In 2010, she served as Flight Engineer for Expedition 23/24. She has logged more than 188 days in space, including over 22 hours in three spacewalks. Dyson has been assigned to her second long-duration mission to the International Space Station as a flight engineer and member of the Expedition 70/71 crew. It will be her third space mission overall. Dyson will launch on the Roscosmos Soyuz MS-25 spacecraft in March 2024. Caption courtesy of NASA.