Possible adaptations include but are not limited to:
For younger students using cardboard, Knex, or Legos and not focussing on precision with the design and crafting of the model. Focus just on making a sketch and then building what they are thinking
If you wish to include robotics/technology you could change the mission to making a functioning rover. Students still design but they are designing a Mars Rover.
Instead of using paper to sketch the floor plan and 3D drawing, consider using computer programs such as Google Drawing to complete these aspects of the process.