The comments are not entirely surprising: Nasa is already working closely with the private sector to resupply the International Space Station. And many private space firms - particularly SpaceX, whose Dragon capsule delivers cargo to the ISS - have made no secret of their ambitions to explore Mars.
Last month, Elon Musk, who founded SpaceX, outlined his proposal for a permanent base on Earth's smaller, colder neighbour.
Reaction to this plan was mixed: some space experts criticised the plan as unrealistic, while others praised Mr Musk for outlining a detailed - and audacious - architecture for getting to Mars.