The Challenge of Closed-loop and Bioregenerative Life Support for Long Duration Space Exploration

Members of the Biosphere 2 team and the University of Arizona faculty will guide an engaging, informed, and relevant seminar on the intricate complexity and real-world challenges of sustaining human life in a sealed vessel for a long-duration mission.

The human drive to reach to the stars has outpaced our understanding of the full scale of biological systems that keep us alive here on Earth. When we aim our rockets to the nearest stars we will be forced to reconcile our relationship to our first home before we endeavor to venture to the next.

The fundamental question, “What is the minimum complexity required to sustain human life for a long-duration mission” will be discussed as a function of physico-mechanical and bioregeneration against the backdrop of research at the University of Arizona’s CEAC, Biosphere 2, SAM, and other analogs and experiments world-wide.

It is the intent of the speakers to leave a solid hour for interactive discussion throughout the program.


Kai Staats is leading the development of a Space Analog for the Moon and Mars (SAM) at Biosphere 2, a hermetically sealed habitat analog. Within this unique vessel teams will conduct research related to plant physiology and ecology, microbial community evolution, CO2 sequestration, water recycling, pressure regulation; human food studies, and with the use of a pressure suit, EVA, tool use, and rover studies, and more.

Kai is also the lead of the SIMOC [see-mok] project, a scalable, interactive software model of an off-world community. SIMOC is built on published data derived from Environmental Control and Life Support Systems (ECLSS) and closed ecosystem research at NASA and universities world-wide. The goal for the users to design a habitat that sustains human life with a combination of physico-chemical ECLSS and bioregenerative (living plant) systems, and is scalable to accommodate a growing community. Kai is a co-author of “World Ships: Feasibility and Rationale” as well as many other publications spanning a wide range of interests.

Trent Tresch works in bridging the gap between traditional aerospace and new-space innovation. Starting his career in aeronautics with ASET Dive into Space, he developed underwater Neutral Buoyancy education programs. While working on more in depth commercial astronautics trainings he began to build the next generation of accessible pressure suits and life support systems with Smith Aerospace Garments. These endeavors further led him to high altitude, manned balloon flight tests and oversight of pressure suit operations. He has co-authored and published in Purdue’s peer review journal, Human Performance in Extreme Environments, and presented on numerous occasions regarding low cost life support systems for exploration and training. Trent is a board member of the Caelus Foundation since the beginning of 2020. He currently resides in Arizona where he is co-developing SAM, the worlds highest fidelity hermetically sealed research habitat at the University of Arizona’s Biosphere 2.

John Adams has helped drive the evolution of Biosphere 2 through positions of progressive responsibility and oversight for two decades. Starting in 1995, after receiving his BS in Wildlife and Fishery Science at the University of Arizona and working on various biology research initiatives in Southern Arizona, Adams became Senior Research Specialist at Biosphere 2, leading the terrestrial research initiatives exploring the effect of elevated CO2 on the complex mesocosms of Biosphere 2.

In 2014, Adams advanced to his current leadership role of Biosphere 2 Deputy Director. In part, the promotion marked a return to his roots, engaging as a key member of the team that plans and directs all research and related activities inside Biosphere 2 and the surrounding campus.

For the past two years Adams has worked closely with SAM Research Director Kai Staats to develop, fund, and construct this unique, hi-fidelity Mars habitat analog and research center.

Dr. Joel Cuello is a professor of Biosystems Engineering at The University of Arizona. Joel designed, developed, and demonstrated the first NASA-sponsored, hybrid solar and electric lighting system for bioregenerative crop production and life support for the Moon and Mars. With 33 years of experience in research and education in controlled environment agriculture (CEA), innovations for the sustainable production of food and high-value bioproducts for both Earth and extraterrestrial applications, Joel has collaborated globally. He is actively engaged through his BioImagineering Lab, designing innovations ranging from microalgae photobioreactors to growing structures for vertical farms and space human habitats.

Joel served as a U.S. National Research Council Postdoctoral Research Associate at the Controlled Ecological Life Support System Division at NASA John F. Kennedy Space Center. Produce Grower magazine named Joel in 2018 as one of the Seven Leading People in Produce, “pushing the produce industry forward.”

Joel and his PhD student Sean Gellenbeck are working with the SAM team, and will join this discussion to lend their expertise in bioregenerative systems for long-duration human space exploration.

Sean Gellenbeck is currently a Ph.D. Student in Biosystems Engineering at the University of Arizona. His research interests include integrated bioregenerative life support systems (BLSS) for human space travel with a focus on modeling a fully integrated system and the inclusion of decomposers into the system architecture.

Sean holds a B.S. in Aerospace Engineering and an M.S. in Systems Engineering both from the University of Arizona. He currently works as a test engineer with Paragon Space Development Corporation testing various ISRU technologies and has previously worked as a systems engineer for the NASA OSIRIS-REx Asteroid Sample Return Mission and as a lab manager for the University of Arizona’s Prototype Mars Lunar Greenhouse (MLGH) Project. He has participated in multiple space research analog missions including a rotation at the Mars Desert Research Station (MDRS) and the Hawaii Space Exploration and Simulation (Hi-SEAS) facility. Sean plans to continue his research and in turn, affect substantial impacts on how food is produced on Earth. He hopes to one day set foot on the surface of Mars.