Scientists and Students Study the Risks of Space Travel

What can happen to the human body in space? Even the healthiest of astronauts may experience bone loss, muscle atrophy, an enlarged heart, vision problems and other complications. Measures to prevent these problems are taken in the form of effective exercise, but the mechanisms of such bodily changes are not well known, making them difficult to fully avert.

Researchers – including Jeffrey Willey, PhD, the Milton Raben Associate Professor of Radiation Oncology – are utilizing new tactics, approaches and exploration quests to keep astronauts safe and healthy throughout their missions. Willey leads the Jeffrey Willey Lab at Wake Forest University School of Medicine and has been involved in five space missions that have studied the physiological effects of deep space flights on astronauts.

“This study is important because, for the first time in a spaceflight study, we’ll get an understanding of how the lower gravitational environment of a Martian environment could impact astronaut health and performance,” - Jeff Willey, PhD, Milton Raben Associate Professor of Radiation Oncology

Willey and his team, which includes two Wake Forest University Graduate School of Arts & Sciences doctoral students, Chirayu Patel and Kaitlyn Reno, and a Wake Forest University undergraduate student, Ethan Payne, are working with NASA to identify how varying gravitational levels in space may contribute to the damaging effects of spaceflight. For their research, they were recently involved in a NASA mission, termed the Joint Partial-Gravity Rodent Research Mouse Habitat Unit-8 (MHU-8), which is a collaboration between NASA, the Japan Aerospace Exploration Agency (JAXA), Harvard Medical School, Northwestern University, Loma Linda University, the University of California-Davis and the University of Tsukuba.

The MHU-8 mission launched aboard SpaceX’s most recent mission to the International Space Station and is the first collaborative rodent mission between NASA and JAXA to test how different gravitational levels can impact health. Mice were launched within JAXA's transportation cage units to the space station aboard the SpaceX Dragon spacecraft. After docking, astronauts transferred the mice to JAXA's Mouse Habitat Unit in the module.

For the duration of the experiment, the mice were housed in centrifuges contained within the JAXA Multiple Artificial-gravity Research System facility, also in the module. The centrifuges exposed the mice to different levels of gravity; specifically, the gravitational environments similar to that of Mars, Earth, an intermediate level and zero gravity of space. The mice returned safely to earth and flight results are being compared with ground studies.

“We know low gravity is damaging to many body systems, but what we don’t know is if we must consider the lower gravitational conditions of Mars and whether it’s relative to Earth as damaging as the much lower levels astronauts face in near zero gravity, like aboard the International Space Station,” said Willey. “From a pure science perspective, the study design will help us understand if there is a threshold gravitational level where damage to the body plateaus – this is key because the progression of many diseases that we see on Earth, from cancer to joint degradation, can involve some similar cellular and molecular responses that are also observed to change during spaceflight.”

The ultimate objective of this overall mission is to study how body systems live and react to different levels of gravity. Researchers also will study the effects on the reproductive system, circadian rhythm, the musculoskeletal system and microbiome.

“This research will help to better protect our astronauts for the upcoming deep space travel missions planned for the moon and Mars. I feel fortunate to be one of the few to have such a unique graduate experience at Wake Forest University, and I plan to continue on in spaceflight research upon graduation.” - Chirayu Patel

For Willey and his team, their first goal was to explore whether artificial gravity, specifically mimicking that of Mars, can preserve hip and knee joint health. Work for this initiative will be performed in Atrium Health Wake Forest Baptist Medical Center’s Comprehensive Cancer Center and within Wake Forest Baptist’s Department of Radiation Oncology and the Department of Comparative Medicine. Atrium Health’s Musculoskeletal Institute will also work in tandem on this project.

“The combined efforts from my work on the MHU-8 study and the Rodent Research 18 mission will help provide a better understanding of spaceflight-induced arthritis at various G-levels," said Patel. “This will help to better protect our astronauts for the upcoming deep space travel missions planned for the moon and Mars. I feel fortunate to be one of the few to have such a unique graduate experience at Wake Forest University, and I plan to continue on in spaceflight research upon graduation.”

The second goal for Willey and his team is to measure whether overall performance can be maintained by using artificial intelligence and advanced imaging to measure how running ability, including stability, is maintained. This is a collaborative project with Wake Forest Baptist’s Department of Orthopaedic Surgery Research Laboratory.

“I feel lucky to not only have been part of a unique international spaceflight mission designed to help preserve astronaut performance, but also that these techniques that we used can be applied to my own cancer-related dissertation project in Jeff Willey's lab.” - Kaitlyn Reno

“We know many body functions and systems are damaged during spaceflight due to microgravity, and likely radiation from the sun and stars, but this project has really been one of the first to directly measure how damage to those systems, or preservation with artificial gravity, can protect actual performance,” said Reno. “I feel lucky to not only have been part of a unique international spaceflight mission designed to help preserve astronaut performance, but also that these techniques that we used can be applied to my own cancer-related dissertation project in Jeff Willey's lab.”

The data collected from this mission will help to further identify the cause, extent and mechanisms of joint damage, including arthritic responses, caused by exposure to spaceflight conditions. As a follow-up to this study, Willey and his team plan to identify if the conditions of the rodent habitats on the International Space Station can impair performance and musculoskeletal health.

MHU-8 is funded by both NASA’s Biological and Physical Sciences division and Human Research Program and JAXA's Human Spaceflight Technology Directorate.