Robert Zubrin
Robert Zubrin is an American aerospace engineer, author, and advocate for human exploration of Mars. He and his colleague at Martin Marietta, David Baker, were the driving force behind Mars Direct, a proposal in a 1990 research paper intended to produce significant reductions in the cost and complexity of such a mission. The key idea was to use the Martian atmosphere to produce oxygen, water, and rocket propellant for the surface stay and return journey. A modified version of the plan was subsequently adopted by NASA as their "design reference mission". He questions the delay and cost-to-benefit ratio of first establishing a base or outpost on an asteroid or another Apollo program-like return to the Moon, as neither would be able to provide all of its own oxygen, water, or energy; these resources are producible on Mars, and he expects people would be there thereafter.
