  The experiment of exo-ecosystem and the exploration of extraterrestrial
habitability aims to explore the adaptation of terrestrial life in space
conditions for the manned space program and the future interstellar migration,
which shows great scientific significance and public interests. By our
knowledge the early life on Earth, archaea and extremophile have the ability to
adapt to extreme environmental conditions and can potentially habitat in
extraterrestrial environments. Here we proposed a design and framework for the
experiment on exo-ecosystem and extraterrestrial habitability. The conceptual
approach involves building an ecosystem based on archaea and extremophiles in a
simulated extraterrestrial environment, with a focus on assessing the
exobiological potential and adaptability of terrestrial life forms in such
conditions through controlled experiments. Specifically, we introduce the
Chinese Exo-Ecosystem Space Experiment (CHEESE), which investigates the
survivability and potential for sustained growth, reproduction, and ecological
interactions of methanogens under simulated Mars and Moon environments using
the China Space Station (CSS) as a platform. We highlight that the space
station provides unique yet relatively comprehensive conditions for simulating
extraterrestrial environments. In conclusion, space experiments involving
exo-ecosystems could pave the way for long-term human habitation in space,
ensuring our ability to sustain colonies and settlements beyond Earth while
minimizing our ecological impact on celestial bodies.
