The use of non-model organisms in medical research is an expanding field. It has already made a significant impact on human health. Insights obtained from the study of unique mammalian traits are being used to develop novel therapeutic agents.
The phenotype of mammalian hibernation supplies unique physiologic and metabolic benefits that are being actively investigated for potential human health applications on Earth. These benefits may also mitigate many of the physical and mental health risks of space travel. The important feature of hibernation is an energy-conserving state called torpor, which involves an active and often deep reduction in metabolic rate from baseline homeostasis. Additional possible benefits include the preservation of muscle tissue and bones despite prolonged immobilization and protection against radiation injury.
Despite this remarkable potential, the space-based infrastructure needed to study torpor in laboratory rodents does not currently exist. Hibernation in microgravity has never been studied. This is an important gap in the understanding of hibernation and its potential applications for human spaceflight. This Phase 1 NAIC grant proposes to remedy this situation through the design and implementation of STASH, a novel microgravity hibernation laboratory for use aboard the International Space Station (ISS). Some unique and critical design features include the ability to maintain STASH at temperatures as low as 4°C, adjustable recirculation of animal chamber air enabling the measurement of metabolism via oxygen consumption, and measurement of real-time total ventilation, body temperature, and heart rate.
The STASH unit will also feature animal chamber sizes that will accommodate the expected variety of future hibernating and non-hibernating species. This will boost its applicability to a variety of studies on the ISS by enabling real-time physiological measurements.
The STASH system is being designed in collaboration with BioServe Space Technologies to be integrated into the Space Automated Biological Laboratory (SABL) unit. This will allow the achievable and practical application of this research to enhance our understanding of both hibernation and mammalian physiology in space.
The short-term goals of the STASH project are investigations into the basic science of hibernation in a microgravity environment. This will lay the foundation for the application of its potential benefits to human health. These benefits include determining whether hibernation provides the expected protection against bone and muscle loss.
The medium-term goals of the project are to begin developing translational applications of hibernation research. These applications include using STASH both for testing bioactive molecules that mimic the transcriptional signatures of hibernation and for evaluating methods of inducing synthetic torpor for their ability to provide similar protection.
As a long-term goal, during a crewed mission to Mars, human synthetic torpor could function as a relevant countermeasure that would change everything for space exploration. It will mitigate or eliminate every hazard included in NASA’s RIDGE acronym for the hazards of space travel. The RIDGE acronym stands for Space Radiation, Isolation and Confinement, Distance from Earth, Gravity Fields, and Hostile/Closed Environments.
Research performed using STASH will be a critical first step toward acquiring fundamental knowledge about the ability of hibernation to lessen the health risks of space. This knowledge will support the development of both biomimetic drug countermeasures and the future infrastructure needed to support torpor-enabled human astronauts engaged in interplanetary missions. The researchers working on STASH consider it to be the epitome of the high-risk, high-reward projects for which NIAC was established.