Kathleen “Kate” Rubins Ph.D. ’06 boarded a mission in November 2020 to conduct scientific experiments under a microgravity environment. She returned to Earth on Apr. 16, bringing updates about her latest research finding.

“Great to be back on the planet!” the NASA astronaut said at the post-flight news conference last Tuesday.

Sunday marks National DNA Day, which celebrates advancements in the field of genomic research. In 2016, Rubins participated in Expeditions 48/49 to conduct scientific experiments in space. She became the first person to sequence DNA in space, research that she continued on her most recent mission — a game changer in the field that opens up possibilities for analyzing various biological samples in space. 

A former Stanford cancer biology student, Rubins’ recent assignment at the International Space Station (ISS) totaled 300 days in space across two flights — charting her as the U.S. female astronaut with fourth most days in space. 

She described her sense of awe and wonder upon glimpsing the Earth for the first time at the press conference: “I was blown away, I couldn’t even talk,” she said. “It is one of those views that never gets old.”

Rubins’ 185-day stay in orbit is part of her preparation for the chance to become the first woman to walk on the moon as soon as 2024. The most recent of the 12 people to walk on the surface of the moon was there on Dec. 19, 1972, as part of the final mission of the U.S. Apollo program. Fittingly, in Greek mythology, Apollo has a twin sister named Artemis, for whom the new lunar landing program is named. 

Prior to joining NASA as one of nine members of the 20th NASA astronaut class, she was a principal investigator at the Whitehead Institute for Biomedical Research at MIT. She studied viral infections that affect Central and West Africa, including Ebola and smallpox. She brought expertise in infectious disease, molecular biology and microbiology to the team at the ISS. 

On Nov. 15, the spacecraft left the Baikonur Cosmodrome in Kazakhstan and docked on the Earth-facing port of the Rassvet module, a part of ISS, after a two-orbit, three-hour flight. While in space, she worked on numerous research projects, including comprehensive microbe sampling of the space station and cardiovascular cell behaviour in microgravity. 

“We were able to advance quite a bit from the 2016 initial sequencing,” Rubins said at the press conference. “[The] team has developed a lot of different ways of processing samples so they can go straight from a swab to a sequence, which is really important if you are looking at microbes or environmental samples.” 

Rubins also spent a large portion of the time aboard the ISS studying how plants sprout in microgravity. Freeze-dried food does not always contain all the nutrients astronauts need, especially for long voyages, so her work could help missions in the future.

“We did get a few to harvest,” Rubins said, describing the radishes that she managed to grow. “I shared these with my crew mates so the whole crew was the first to eat radishes in space.”

Space biology research will also be crucial to the success of the Artemis exploration program, according to aerospace and astronautics associate professor Simone D’Amico.

“New genetics and biological techniques are needed to understand how life adapts and changes during spaceflight,” he said, adding that ultimately, the goal is to support human exploration of the moon and Mars. Gaining more insights here, such as how fluids move around plant roots in microgravity, is necessary for carrying out large-scale crop growth.

Conducting day-to-day biological experiments in space comes with various challenges. In an earlier interview with microbiology and immunology professor David Relman, Rubins described the practical challenges of conducting experiments in space. 

“Everything is floating,” she said. “Nothing is tacked down on your lab bench. You have to put velcro on every piece of equipment.” 

One of Rubins’ ongoing interests during her time in space was to establish a full microbial map of the space station, which she initiated during her latest trip by collecting 800 different environmental samples in the Space Station. 

In an email to The Daily, Relman explained that studying the microbiome of human-inhabited spacecraft will offer multiple interesting insights. 

“Spacecraft in particular are the ultimate example of a closed environment, with tightly regulated environmental and life-support processes,” he said. “The role of microbes in adapting to, and modifying such environments, is relevant for our understanding of the interplay between microbial communities and human-associated environments on earth, including for managing and mitigating microbial community processes.”  

Relman added that better understanding and anticipation of microbial threats to human health will be critical as humans begin to look into long-term space travel. Understanding ways in which humans contaminate their local environments and the way environmental microbes could threaten our health will guide future investigation on how to best monitor and control these issues.

When there’s any possibility of discovering extraterrestrial life forms, NASA investigates how to ensure that nothing on a foreign celestial body is exposed to earthly disease. According to Rubins, the moon is a very good control for Mars. Sampling everything that astronauts are bringing with them to the moon will help them develop a library and catalog of microbial population. 

“I think it would be a really incredibly interesting experiment to sample the lunar surface just as we’re doing the course of our exploration and understand our microbial footprint,” Rubins said.

The crews on board NASA SpaceX Crew-1 mission, which coincided with Rubins’s travel, are scheduled to return to Earth on Wednesday, April 28. Rubins said that she’d love to go back to the space station again, and for the next expedition she’ll bring a few photographs of family, a journal and mostly “the sense of awe and wonder.”

This article has been updated to reflect that Kate Rubins was the first person on the planet to sequence DNA rather than the first woman.

A previous version of this article incorrectly attributed a quote to Rubins instead of Relman. The Daily regrets this error.