The Case for Mars (46 page)

and that the global temperature distribution is given by:

where θ is the latitude (north or south).

Equations (1)
through (4) give the temperature on Mars as a function of carbon dioxide pressure. However, as mentioned above, the carbon dioxide pressure on Mars is itself a function of the temperature. There are three reservoirs of carbon dioxide on Mars: the atmosphere, the dry ice in the polar caps, and gas adsorbed in the regolith. The interaction of the polar cap reservoirs with the atmosphere is well understood and is given simply by the relationship between the vapor pressure of carbon dioxide and the temperature at the poles. This is given by the vapor pressure curve for carbon dioxide, which is approximated by:

So long as there is carbon dioxide in both the atmosphere and the cap, equation (5) gives an exact answer to what the carbon dioxide atmospheric pressure will be as a function of polar temperature. However, if the polar temperature should rise to a point where the vapor pressure is much greater than that which can be produced by the mass in the cap reservoir (between 50 and 100 mbar) then the cap will disappear and the atmosphere will be regulated by the regolith reservoir.

The relationship between the regolith reservoir, the atmosphere, and the temperature is not known with precision. An educated guess developed by McKay
⁴⁴
is:

where M
_a
is the amount of gas adsorbed in the regolith in bars, C is a constant adjusted so that equation (6) will reflect known Martian conditions, and T
_d
is the characteristic energy required for release of gas from the regolith (the “desorption temperature”). Equation (6) is essentially a variation of a well-known law for the change in chemical equilibrium with temperature, and so there is fair confidence that its general form is correct. However, the value of T
_d
is unknown and probably will remain so until after the human exploration of Mars. While we don’t know what the right value for T
_d
is, we can bracket the problem by varying T
_d
from 15° to 40°K (the lower the value of T
_d
, the easier things are for prospective terraformers). Then we use the global temperature distribution given by equation (4) to integrate equation (6) over the surface of the planet to give us a global “regolith pressure.” This gives a reasonably accurate quasi two-dimensional view of the atmosphere/regolith equilibrium problem in which most of the adsorbed carbon dioxide is distributed to the planet’s colder regions. Thus, in our model, regional (in the sense of latitude) temperature changes, especially in the near-polar regions, can have as important a bearing on the atmosphere/regolith interaction as changes in the planet’s mean temperature.

The results of this model, displayed graphically throughout this chap, give strong reason to believe that Mars can be terraformed.

10: THE VIEW FROM EARTH

No bucks, no Buck Rogers.

—Anonymo
us

In the past nine chapters I’ve sketched out the technical possibilities and the vision of what we can accomplish by launching a humans-to-Mars program. Now it’s time to come back to Earth. The greatest obstacle to gaining a foothold on Mars won’t be found in the engineering details of a human Mars mission. It won’t be found in the rigors of the journey to Mars and the long days exploring a new world. It won’t be found on Mars. The greatest obstacle to sending humans to Mars resides here on our present home planet in the guise of Earthly politics. How can we get the money needed to get the program off the ground?

Some people think it can’t be done. They point to the failure of President Bush’s Space Exploration Initiative (SEI) as proof of the fact that the American political process will not support a humans-to-Mars program. The logic behind this “proof,” though, is intrinsically flawed, as it is based upon the notion that because something happened a certain way once, it
has
to happen that way again. Bush tried to repeat John F. Kennedy’s successful launching of the Apollo race to the Moon, they say, but in the environment of the 1990s the clarion call fell flat. The SEI failed, therefore it was inevitable that it should fail, therefore all future SEIs will fail. Q.E.D.

All very tidy, but completely
inaccurate. Bush did
not
do for SEI what JFK did for Apollo. Rather Bush did for SEI what Bush did for the Kurds: announce that the hour had struck, toss the ball in the air, and walk off the field. As Dwayne Day of the Space Policy Institute has pointed out, “Bush was an advocate of space exploration in the same way he was ‘the environmental president’ or ‘the education president’—weakly, and in name only.” It is also true that NASA’s 90-Day Report with its $450 billion price tag and thirty-year timeline did not help the situation, but the real problem was not the 90-Day Report, but a leadership willing to tolerate the flaws inherent in that report.

Let me make clear exactly what I mean. In June of 1990, when SEI was still in the initial stages of its downward plunge, I attended a large NASA-sponsored SEI propulsion conference at Pennsylvania State University. Addressing the plenary session of that conference, Congressman Robert Walker (R-PA) openly told representatives of the aerospace industry and aerospace press that the reason SEI funding had just been voted down in Congress was because the top NASA brass—led at that time by administrator Richard Truly—had told Congress that if NASA got what it wanted for the Space Shuttle and Space Station programs, Congress was welcome to vote however it pleased on funds for SEI. In other words, the NASA leadership refused to advocate the program that President Bush had called a national priority. Plenty of people thought this was veritable sabotage and that Truly should have been fired. The National Space Council’s leaders at the time, Mark Albrecht and Pete Worden, tried to deal with the situation, but due to presidential apathy it was two years before Truly was replaced. By that time, SEI was virtually dead.

Bush’s lack of involvement, combined with the NASA leadership’s opposition, left SEI an orphan to be advocated by some Space Council staffrs allied to a few friendly congressmen. Without any real clout, they were forced to try to fund SEI by sneaking a few small appropriations through Congress. When the administration’s political opponents saw this weakness, they pounced upon it as a way to humiliate Bush and his Space Council chief, Dan Quayle. Kevin Kelly, an aide to Senator Barbara Mikulski (D-MD), led the massacre to seek out and systematically eliminate any NASA appropriation, no matter how small, that could be linked to SEI. By the time Dan Goldin became NASA admi
nistrator in 1992, the best way left to save those technology programs needed for a Mars program that still survived was to break the damning link by abolishing SEI, and, after a year or so of attempts to salvage SEI, that is what he did.

Comparing the brilliant military/political strategist Napoleon Bonaparte to his dissolute grandnephew Napoleon III, Karl Marx once commented, “All historical events occur twice, the first time as tragedy and the second time as farce.” The comparison holds equally well for JFK and Bush. It is said that while his army was being annihilated at Sedan, Napoleon III whiled away the time by playing billiards. It might be said that Bush lost Mars while yachting at Kennebunkport. The failure of SEI proves nothing, except that armies don’t win battles if their generals are playing billiards.

There is plenty of latent political support in this country for a humans-to-Mars program. I have experienced this firsthand when speaking on the subject before numerous public groups of every description, from Rotary Clubs to plumbers’ conventions, groups with no vested interest in a Mars program as such. And the central recurring question I get is “How come we’re not doing this?” “I remember Apollo,” people in my audiences tell me. “Weren’t we supposed to go to Mars after that? How come there was no follow-through? This is the sort of thing this country ought to be doing!”

That is what I hear, over and over again. The main public complaint about the space program
isn’t
that it costs too much; it’s that the program is not going anywhere. People feel betrayed, not by NASA, but by the politicians. The future they expected to see in the 1960s has been aborted. What’s happened? How come we stopped moving? The Beltway policy wonks may tell the politicians that people in the heartland don’t care about space, but everything I see firsthand tells me there is a massive disconnect here.

Some might challenge the evidence for my assertion as purely anecdotal. But if you require scientific polls, they’ve been produced in plenty. In a poll
Newsweek
sponsored in connection with its article on Mars Direct, more than half of those queried supported a piloted mission to Mars. Likewise, in a CBS News poll conducted about the same time (the summer of 1994) a majority of those polled supported a humans-to-M
ars mission. An ABC
News/Washington Post
poll conducted in early 1996 found that a majority of Americans believed that the space program had brought enough benefits to the country to justify its costs.

Other forms of statistical data have been collected as well. For a number of years, Jon D. Miller of the Chicago Academy of Sciences has reported on the public understanding of science and technology in the United States.
⁴⁵
Included in his reports are examinations of that sector of the population termed the “attentive public” to various science and technology issues. The attentiv
e public is that group of individuals who are interested in a specific issue, who feel they are well informed about the issue, and stay curr by regularly reading newspapers or magazines. They are informed enough to feel comfortable and confident in perhaps contacting a policymaker on the issue. In other words, the attentive public for an issue is that portion of the public that might be most prone to take action to support, or oppose, an issue. Those who are interested in an issue, but don’t believe they are terribly well-informed, Miller classifies as the “interested public.” From data collected in 1992, Miller concluded that 6 percent of the American public was attentive to space exploration, and an additional 16 percent were interested in the subject. According to Miller, the large majority of those 22 percent were found to believe that the benefits of space exploration outweigh its costs. Twenty-two percent is still a minority. But Miller also found that his “attentive” group had the highest proportion of scientifically literate individuals among its members, and was one of the best educated groups in his study of the U.S. population as a whole.

In other words, Miller’s attentive group maps strongly onto the scientific minds of the country, and it is not a small group. The 6 percent Miller identifies as attentive to space represents nearly 11 million adult citizens, and the interested public forms a pool of nearly 30 million citizens. Together they total more than 40 million potential adult voters.