Cryopreservation of Organisms in Space in Preparation for Interstellar Travel

Authors: Alvaro Diaz Flores, Claire Pedersen, Athip Thirupathi Raj, and Jekan Thangavelautham

Background: The next stages of human exploration towards the outreaches of the solar system and into interstellar space will require traveling vast distances that will inevitably take very long travel times. Taking on such risk in search of new habitable planets is warranted, considering Earth faces several existential threats that can result in mass extinction at any time.  However, such long travel poses challenges, namely the fate of the crew as they age.  Could the crew, over time, fall into conflict, jeopardizing the entire mission? If the journey were to require multiple generations, would later generations have the same motivation or will to proceed? Such a journey will require us not to fail.

Objective: Our objectives are to determine the practical benefit of putting a human crew and living organisms in cryogenic stasis (below -180 ^oC) for long journeys.

Methods: By keeping the crew in stasis and fresh at their destination, we can avoid the organizational challenges described earlier.  This journey will require transporting not just a human crew but an entire support ecosystem.  Keeping an ecosystem in stasis is a smart option that minimizes complexity in operation and could potentially avoid risks of disease or mutational damage spreading during the journey. Yet important questions remain, particularly the effect of micro-gravity and low-gravity conditions. For these reasons, we have set out to better understand cryo-preservation under space and low-gravity. We propose the development of a prototype cryogenic laboratory that would operate on the International Space Station.  The laboratory would be composed of a 12U CubeSat that would be spun at 22 RPM, with the cryo-container located at a distance of 0.3 m from the spinning axis to simulate lunar gravity.  The lab would contain six cryo-bags, two having tardigrades, two containing mice eggs/sperm, and two containing chicken eggs/sperm.  The test will need to be performed for years and repeated with other organisms.

Results and Conclusions: Our work has developed a prototype design model of this facility and determined electrical and thermal needs, and all appear to be feasible. Our next steps are towards the development of a laboratory prototype to advance the component technologies.