She is the founder of Proudly Human,[3] an initiative of which is the Off-World Project, a series of habitation experiments in Earth's most extreme environments.

[4][10] In 2019, Marais founded Proudly Human, an organisation focusing on building infrastructure and teams in extreme environments in preparation for life on the Moon, Mars and beyond, as well as to provide solutions for those living in harsh conditions here on Earth.

[3][5] She is a member of the South African government advisory task team on the 4th Industrial Revolution (4IR), the combination of hardware, software, and biology with a focus on communication and connectivity.

Over the next few years, Proudly Human will run a series of habitation experiments, building communities and off-grid infrastructure in the most extreme environments on the planet, from the desert, to Antarctica, to under the ocean.

[5] Marais was a special project coordinator of the Foundation for Space Development in 2016,[6] and in 2017, became co-director[4] with Carla Sharpe and Khutšo Ngoasheng.