Explore the challenges of living on Mars! Living off-world, far from home is not as easy as science fiction makes it seem. It takes a careful balance of astronauts, food rations, air and water recycling, greenhouse and plants, agriculture, and solar energy production to keep this ecosystem running. With this interactive simulator built on authentic NASA data, you design your mission, set it in motion, and learn if you will need more than potatoes to survive! Use this simulation with your students to reflect on what it takes to keep the OG spaceship running smoothly: Earth.


5 - 12+


Biology, Earth Science, Astronomy, Engineering

We will in the coming decades establish ourselves in orbit around the Moon, on the surface of Mars, and in a more distant future on moons of Jupiter and Saturn. To get there we must learn how to sustain human life in hostile environments, with limited resupply.

SIMOC [see-mok] is a scalable, interactive model of an off-world community. The model is founded on published data derived from life support and closed ecosystem research at NASA and universities world-wide. The users are invited to design a habitat that sustains human life through a combination of physico-chemical (mechanical) and bioregenerative (living plant) systems, selecting various combinations of crew quarters, greenhouse, food and plants, energy generation and storage, and mission duration.

Sound simple? Science fiction has made it look too easy with airlocks that never require decompression, food materializing out of thin air, and the processing of waste or recycling of air something that happens off-camera. In the real cosmos, living off-world is far more challenging. Finding a balance of machines, plants, and humans is a complex endeavor. The slightest incongruity in waste management, power production, or carbon dioxide scrubbing can result in catastrophic failure, forcing the abandonment of the habitat, or worse.

After 50 years in low Earth orbit, solutions for living in space remain heavily biased toward mechanical systems and resupply missions. This is not a long-term solution if we desire to establish new homes among the stars. SIMOC is a place to experiment, to test theories, and make mistakes—to explore.

The SIMOC team has developed free curricula for grades 5-8 and 9-14, with guidance for both teachers and students. These classroom lessons are aligned with Next Generation Science Standards (NGSS), Common Core State Standards, and 21st Century Skills. Give the lessons a try and help build a future for off-world communities throughout the solar system, as well as a greater understanding of our first spaceship—Earth.
If you are new to SIMOC, we encourage you to read the First Time User page at where you will also find a wealth of information, resources, and educational guidelines.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Project Lead
Kai Staats
Lead Server Developer
Iurii Milovanov
Lead Front-End Developer
Ezio Melotti
Assistant Developer
Thomas Curry
Habitat Architect and 3D Artist
Bryan Versteeg
ASU Associate Lead
Sheri Klug Boonstra
Educational Lead
Don Boonstra
Tyson Brown, National Geographic Society
Sarah Appleton, National Geographic Society, National Geographic Society
Last Updated

December 20, 2022

For information on user permissions, please read our Terms of Service. If you have questions about licensing content on this page, please contact for more information and to obtain a license. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. She or he will best know the preferred format. When you reach out to him or her, you will need the page title, URL, and the date you accessed the resource.


If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.


Text on this page is printable and can be used according to our Terms of Service.


Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources