As humanity prepares for longer journeys into the cosmos, the challenges of maintaining crew health, ensuring adequate life support systems, and addressing the impacts of prolonged spaceflight are becoming increasingly urgent. Imagine a scenario straight out of a science fiction movie: putting astronauts into a state of hibernation or “suspended animation” during long space missions. This not only could alleviate the demands of food and life support but also offers a potential solution for treating severe injuries or illnesses that might occur during interstellar travel.

The dream of sending humans to distant planets is constrained by the realities of our biological limits and the need for sustenance. However, any technological advancements that can reduce these life support requirements or extend human lifespan could significantly enhance our ability to embark on more ambitious exploratory missions.

Hibernation is a natural and beneficial process utilized by many mammals to conserve energy. Yet, a principal obstacle to successfully inducing hibernation in humans lies in preserving effective blood circulation at lower body temperatures. This is intricately connected to the viscoelastic properties of red blood cells (RBCs).

Recent research examined the thermomechanical characteristics of RBCs from three different species: the hibernating common noctule bat (Nyctalus noctula), the non-hibernating Egyptian fruit bat (Rousettus aegyptiacus), and humans (Homo sapiens). Studying RBCs at temperatures representative of regular and hibernating conditions revealed crucial findings: elasticity and viscosity of the cells increased significantly as temperatures dropped.

Interestingly, the adjustment of RBCs to temperature changes is primarily governed by the properties of their membranes rather than the cytosol. The viscous dissipation in the membrane of bat RBCs is up to 15 times greater than that observed in humans. This indicates that as the temperature decreases, the RBCs of both bat species transition to a more viscous-like state, which is essential for maintaining circulation.

The minute adjustments in RBC viscoelasticity are comparable to the seasonal fluctuations observed throughout the year. However, these findings suggest that external factors, such as diet, have a lesser impact on RBC functionality in differing temperatures compared to the intrinsic properties of the cell membrane.

In conclusion, the research highlights the potential of manipulating membrane viscoelasticity as a means to support blood circulation at lower temperatures in humans. This could serve as a foundational step towards developing safe synthetic torpor, paving the way for revolutionary advances in both medicine and space travel. As we continue to explore how hibernation mechanisms can be harnessed, the dream of interstellar exploration may become a reality sooner than we imagine!