• Class III: in-situ resource utilization (ISRU) derived structure with integrated Earth components.
[3] Class I structures are prepared and tested on Earth, and are designed to be fully self-contained habitats that can be delivered to the surface of other planets.
In an initial mission to put human explorers on Mars, a Class I habitat would provide the bare minimum habitable facilities when continued support from Earth is not possible.
The Class II structures call for a pre-manufactured kit-of-parts system that has flexible capacity for demountability and reuse.
To facilitate the development of technology required to implement the three phases, Cohen and Kennedy (1997) stress the need to explore robust robotic system concepts that can be used to assist in the construction process, or perform the tasks autonomously.