The Space Shuttle, intended to make access to space easy and inexpensive with its partially reusable design, proved high-maintenance and expensive, and revealed weaknesses in both its design and in NASA’s culture through the late 1980s. The Challenger disaster of 1986, which resulted in 7 deaths after the vehicle disintegrated due to a cold-compromised O-ring on the right solid rocket booster, was found to have resulted from a problem that was not only known about, but that the launch managers had explicitly been warned of by engineers. For over 2 years, the Shuttles were grounded as NASA and independent investigators looked at the root causes of the accident, finding evidence of failed communication and corner cutting in the name of meeting launch schedules. But even with reforms and improved oversight, the Shuttle’s intrinsic flaws were made disturbingly evident in STS-27 in December of 1988, where damage to the Space Shuttle Atlantis during takeoff was so severe that astronaut Hoot Gibson thought the crew was going to die on reentry.

Damage to SS Atlantis during STS-27 (hosted on Spaceflightnow, credit NASA)

In spite of these disturbing incidents, the Bush administration signaled a resurgence in American space development. The Space Exploration Initiative (SEI), and the resulting 90 Day Report commissioned by NASA administrator Richard Truly, laid out a complex Mars plan-multiple rovers to locate an ideal landing spot, exhaustive research into life support and micro-gravity aboard the planned Space Station, construction and use of fuel depots in orbit and on a planned Moon base, and a crewed Mars mission that involved the in-orbit construction of an enormous ship.

This plan was doubtless a major topic of discussion and debate at chapters of the National Space Society (NSS) from the moment it was released. This eclectic collection of aerospace engineers, physicists, tinkerers, nuclear scientists, science fiction fans and astronomers was formed in 1987 from the merger of groups devoted to the ideals of legendary rocket scientist Wernher von Braun and space habitat designer and physicist Gerard O’Neill. For these people, space exploration and colonization were key to the survival and success of a liberated and prosperous humanity, and getting the word out to the demoralized masses was urgent.

On May the 28th of 1990, a conference hosted by the NSS was held in Anaheim. Robert Zubrin, then working at aerospace corporation Martin Marietta as a senior engineer, took the podium near the end, an assistant manning an overhead projector with a ream of transparencies. The 37 year old Brooklynite had a double masters in Nuclear Engineering and Aeronautics and Astronautics from the University of Washington, and had risen far up MM’s ladder in a short time based off of his fiendish brightness and fanatical work ethic. He and a team of a dozen elite engineers from the aerospace corporation had prepared an alternative plan. A video of his presentation is below-

(The video is long, but please watch it. It is captivating and at times quite funny-Zubrin is a strong, quick-witted speaker.)

There was no room for interpretation-Robert Zubrin thought NASA’s plan was garbage. The estimated half-trillion dollar cost, the workload of having to make many launches just to build the ship, the time-consuming and circuitous path to finally landing people on Mars-it was a disaster. A white elephant project vulnerable to cancellation due to shifts in the political wind. The alternative plan they had crafted, known as Mars Direct, was simple and fast, with a goal of putting human feet on Mars before the year 2000. The proposed system, using an initial unmanned landing craft fitted with a nuclear reactor followed later by additional craft with and without people, made extensive use of Mars’s own atmosphere for generating methane and oxygen to use as fuel for rockets and vehicles on the surface of the planet, and called for extended stays on the planet, not the 2 week glorified vacation proposed by SEI. More advanced concepts for nuclear thermal rockets and massive colonization ships were discussed, but the core of Mars Direct used dead-simple chemical rockets incorporating parts in active use at NASA to save money.

An artist’s rendition of Mars Direct (Source)

Perhaps even more influential than the outline of a far simpler, more practical path to Mars was the reason for exploring and eventually colonizing Mars that Zubrin offered. The potential for rich, easily harvested mineral resources on the planet was brought up, but it was Zubrin’s quote from Pilgrim William Bradford about the proposition of their journey to the Americas that evoked the heart of his argument-

Mars was the frontier that the world had been missing-a place to make new civilizations, to push humanity to innovate and adapt. And beyond Mars, innovation would progress-new forms of rocketry, designed to make it faster to go to Mars, would open up the outer solar system, and later nearby star systems, in a cascading wave of colonization and expansion. Zubrin ends the presentation by evoking the wisdom of Pericles: that if we embark on the colonization of Mars,and accordingly the expansion of humanity to the solar system and then to the stars, that in future ages,our far-flung descendants, living on planets scattered across the galaxy, will look back on the wonders we worked, as backward and primitive as we were, with awe and gratitude.

The NSS gave Robert a standing ovation. The fire was lit. To Mars!

But for NASA, dreams of grand exploratory space missions were soon squashed-the SEI’s great expenses made it politically unworkable, just as Zubrin had warned-the Space Station and low earth orbit human activity lived on, but deep space human missions were snuffed in favor of rovers and probes. Over the decades that have followed, new plans for Mars missions have come and gone, and as of 2020, NASA’s earliest estimate for a human presence on Mars is in the 2030s.

These delays have done nothing to deter Dr. Zubrin. His public advocacy in favor of the human colonization of Mars has been relentless-he founded the Mars Society in 1998 to promulgate the idea, and has been a constant advocate for an increased human presence in space, appearing in documentaries, giving talks at universities and conferences, and publishing several critically acclaimed books about his ideas such as The Case For Mars and more recently The Case for Space. And that advocacy has paid off in spades, albeit not directly.

No government or corporation has directly copied the Mars Direct plan but the DNA of the concept is obvious in SpaceX’s Mars colonization plans. The New Space juggernaut plans to use in situ resources gathered from the atmosphere of Mars, long duration surface missions, and will be going straight to Mars rather than building a huge spaceship in orbit or needing fuel depots on the moon. Although Dr. Zubrin is generally positive about SpaceX, he’s also offered significant criticisms of the particulars of their strategy, seeing the landing of such a large and powerful ship as the Starship on Mars as a waste of its reusable capability, preferring a much smaller 3rd stage to make the actual journey to the red planet.