Kathleen Hallisey “Kate” Rubins is an American microbiologist and retired NASA astronaut whose career has linked high-consequence pathogen research with the development of molecular biology tools for human spaceflight. Born on October 14, 1978, in Farmington, Connecticut, she grew up interested in both science and space exploration. She graduated from Vintage High School in Napa, California, in 1996, earned a Bachelor of Science in molecular biology from the University of California, San Diego, in 1999, and completed a Ph.D. in cancer biology in 2005 from Stanford University Medical School’s Biochemistry Department and Microbiology and Immunology Department. Her doctoral thesis, advised by Patrick O. Brown, examined host and viral responses during poxvirus infection.
As an undergraduate at the Salk Institute for Biological Studies, Rubins worked in the laboratory of Frederic Bushman on the mechanism of HIV-1 integration into host genomic DNA. That research included studies of HIV-1 integrase inhibitors and genome-wide analyses of integration patterns, contributing to the identification of compounds that interfered with a key viral enzyme. At Stanford she collaborated with the U.S. Army Medical Research Institute of Infectious Diseases and the Centers for Disease Control and Prevention to develop the first animal model of smallpox infection. Rubins was responsible for constructing the underlying microarray used in the work; the successful infection of macaques provided a platform for testing vaccines and treatments against a virus eradicated in nature but retained as a biosecurity concern.
After her doctorate she became a fellow and principal investigator at the Whitehead Institute for Biomedical Research, affiliated with MIT. She headed a group of roughly fourteen researchers focused on viral diseases that primarily affect Central and West Africa. The laboratory’s work covered poxviruses (including smallpox and mpox), filoviruses (Ebola and Marburg), and arenaviruses (Lassa fever), with emphasis on viral and human immune-system genomics, RNA regulation, and host-pathogen interaction. She and members of the lab participated in fieldwork in the Democratic Republic of the Congo, and the group collaborated with U.S. Army researchers on the development of potential therapies for Ebola and Lassa viruses. These projects established her as a specialist in high-consequence pathogens and in the genomic tools needed to study them under constrained conditions.
NASA selected Rubins in July 2009 as a member of Astronaut Group 20. She completed candidate training and subsequently served in technical roles supporting crew health and biomedical hardware before her first flight assignment. On July 7, 2016, she launched aboard Soyuz MS-01—the first flight of the upgraded Soyuz MS spacecraft—with Russian cosmonaut Anatoli Ivanishin and Japanese astronaut Takuya Onishi. She served as flight engineer on Expeditions 48 and 49, returning to Earth on October 30, 2016, after 115 days. During the mission she contributed to more than 275 scientific investigations spanning molecular and cellular biology, fluid physics, and crew-health monitoring.
The defining technical achievement of that flight was the first DNA sequencing performed in space. Using a portable Oxford Nanopore MinION device, Rubins sequenced samples that included mouse, bacterial, and viral DNA. Within weeks the team had passed one billion base pairs sequenced aboard the station; across the series of experiments she ultimately sequenced more than two billion base pairs. Parallel ground controls showed that microgravity did not degrade sequencing performance relative to Earth-based runs. The work demonstrated that sample handling, bubble management in fluids, and data generation were feasible in orbit, opening a path toward in-flight microbial identification and medical diagnostics. She also cultured cardiomyocytes, performed quantitative real-time PCR, and conducted microbiome experiments, while helping integrate biomedical hardware for long-duration cell culture.
Rubins completed two spacewalks on the first mission, working with NASA astronaut Jeff Williams to install the first International Docking Adapter and to retract a thermal radiator. Her second long-duration flight began on October 14, 2020, aboard Soyuz MS-17 from Baikonur. As flight engineer on Expeditions 63 and 64 she returned on April 17, 2021. The mission extended her sequencing work, advanced heart-cell and organoid studies in microgravity, and continued microbiology investigations aimed at characterizing microbes that could affect crew health on future exploration vehicles. She performed two additional spacewalks. Across both flights she logged 300 days, 1 hour, and 31 minutes in space and accumulated 26 hours and 46 minutes of extravehicular activity time on four spacewalks.
Between and after the missions, Rubins held ground assignments that shaped NASA’s human-health architecture. She served as acting deputy director of the Human Health and Performance Directorate and as the Astronaut Office lead for development of the spacesuits intended for Artemis lunar surface operations. These roles connected her laboratory experience with the operational requirements of sustained presence beyond low Earth orbit, including molecular diagnostics that could identify pathogens or monitor crew physiology without immediate return to Earth.
After her second flight she commissioned as a major in the U.S. Army Reserve Medical Service Corps, serving as a microbiologist. She has held the position of innovation officer with the 75th U.S. Army Reserve Innovation Command’s MedBio Detachment. In November 2024 she received the Basic Aviator Badge with Astronaut Device. Rubins retired from NASA on July 28, 2025, after sixteen years with the agency. She subsequently became the inaugural director of the Trivedi Institute for Space and Global Biomedicine at the University of Pittsburgh, an organization focused on translating molecular and cellular techniques developed for low-Earth orbit and resource-limited settings into broader biomedical applications.
Rubins’s scientific record therefore spans the construction of the first smallpox animal model, genomic characterization of African viral pathogens, the first demonstration of DNA sequencing in microgravity, and the operational integration of those methods into space-station and lunar-suit planning. The sequencing results established that nanopore technology could generate comparable data quality on orbit and on the ground, supporting future uses in environmental monitoring and medical diagnosis during missions where sample return is impractical. Her combined laboratory, flight, and reserve service illustrates a continuous line from pathogen genomics to the biomedical infrastructure required for extended human exploration.