UF study finds plants respond almost immediately to spaceflight

Plants begin responding to spaceflight almost immediately after leaving Earth, according to a new University of Florida study that captured the earliest stages of biological adaptation during a commercial suborbital mission.

Published in the journal npj Microgravity, the study reports the results of an experiment conducted by a UF astronaut during Blue Origin’s New Shepard NS-26 flight on Aug. 29, 2024.

For more than two decades, UF space biologists Rob Ferl, Ph.D., and Anna-Lisa Paul, Ph.D., have worked together to understand how living organisms respond to spaceflight. For this study, they designed an experiment to capture biological changes during different phases of a mission.

Scientists have long studied how plants and other organisms respond after spending days, weeks or months in space. Much less has been known about the biological changes that occur during the first minutes of spaceflight and how those responses change as a mission unfolds.

“The science to be done in suborbital space is real and worth the trip,” Ferl said. “There is tremendous intrinsic value in the suborbital realm itself, including understanding rapid changes in biology during various phases of spaceflight, especially the first few minutes of being in space.”

For the mission, Ferl carried dozens of Arabidopsis plants in specially designed tubes attached to his flight suit that he activated at four different points during the trip to space and back: prior to launch, upon reaching microgravity, at the end of the weightless period as the vehicle began its descent, and upon landing. The tubes of plants were prepared prior to the flight by Paul and colleague Jordan B. Callaham, and then Paul delivered them to the Blue Origin Capsule team before launch.

At the Payload Processing Facility on the ground, Callaham tracked Ferl’s progress and activated a corresponding set of control tubes at the same times, while Paul set out to meet the capsule and lead the landing operations in the field. The coordinated operation allowed researchers to compare the plants exposed to spaceflight with identical plants that remained on Earth and to examine how the flight samples changed from one phase of the mission to the next.

The devices, known as Kennedy Space Center Fixation Tubes, preserve biological material at the moment they are activated. The tubes, which the UF team helped design, have been used for hundreds of samples collected during Space Shuttle and International Space Station missions. Using them aboard New Shepard allowed the UF researchers to apply a proven orbital research technology to suborbital spaceflight.

Paul said the hours of training and preparation the team completed before the mission proved invaluable. Activations had to occur at exactly the right moments, both in flight and on the ground, to create meaningful comparisons between the spaceflight samples and their Earth-bound controls.

The results provide one of the clearest views yet of what happens during the transition from Earth to space. The researchers identified more than 1,200 genes whose activity changed during the flight. The responses differed between leaves and roots and varied across different phases of the mission.

Many of the affected genes are involved in how plants respond to environmental stress and changing conditions. The results indicate that acclimation to spaceflight is not a single biological adjustment that occurs after an organism reaches space. Instead, it is a progressive process involving different responses during launch, entry into microgravity, descent and return to Earth.

“The ability to preserve samples at several points during the flight allowed us to look at the transition itself, rather than simply comparing plants on Earth with plants that had already spent time in space,” Paul said. “The results show that the plants’ responses changed as the flight progressed, giving us a more detailed picture of how biological acclimation to spaceflight unfolds.”

In addition to producing the biological findings, the mission demonstrated that an academic researcher could personally conduct an experiment during a spaceflight in a “shirtsleeve” environment, without relying entirely on automation or specially trained astronauts.

Many spaceflight experiments must either operate autonomously or be conducted by astronauts responsible for a wide range of investigations. During NS-26, Ferl flew for the specific purpose of tending the experiment that he and Paul had developed. He was able to observe the sampling process, verify that preservatives properly covered the samples, adjust the movement of the tubes to ensure rapid preservation and record observations about the timing and quality of each sample.

Ferl explores the broader implications of scientists flying with their experiments in a Perspective column in the same issue titled “The long arc of scientists in spaceflight: scientists flying with their experiments.” 

In the article, Ferl draws on his own flight aboard Blue Origin’s New Shepard to make the case for putting scientists in space with their experiments. “Putting the personal researcher into the loop creates better science and better scientists,” Ferl writes, arguing that firsthand observation of an experiment can provide insights that are difficult to achieve remotely.

The successful mission demonstrated that scientists can effectively manage their own experiments during spaceflight and that commercial suborbital spacecraft can serve as research platforms. The approach gives researchers direct insight into the environment surrounding an experiment and opportunities to make observations that would not be available through automation or remote monitoring alone.

The work was funded by NASA’s Flight Opportunities program, with supplemental science support from NASA Biological and Physical Sciences. Kennedy Space Center experts supported the use of the fixation tubes, and Blue Origin worked with the researchers to develop the protocols and procedures needed to conduct the experiment aboard New Shepard.

Co-authors of the study included Callaham, Hunter F. Strickland, Ph.D., Vicken Aknadibossian, Ph.D., Owen Marr and Paula Adhikari.