A perennial debate among the community of space policy “experts” (whose number apparently consists of about 4/5 of the Earth’s population) is about the value of human spaceflight. As is the wont in such debates, science and its relation to human missions often emerges as a theme. One might think that nothing new could possibly be said about this issue – and they’d be largely correct. Nonetheless, the most recent kerfuffle caught my eye, in part because of the large degree of ignorance associated with the arguments advanced.
This flare-up was generated by a piece at Slate from science journalist Charles Seife. Although written ostensibly about the “purpose of NASA,” Seife uses that rhetorical question to springboard his advocacy for the termination of human spaceflight. His piece has most of the usual canards in common with other literature in this regard – the science is poor, it’s too expensive, it’s too dangerous. Seife cites the Hubble servicing missions as an example of human spaceflight’s “alleged” benefits and claims that for what those five Shuttle missions cost, we could have built two new Hubble telescopes. He might want to look at the funding history of the James Webb Space Telescope before he trots out that argument. But the more culpable point that Seife doesn’t mention is that without the Shuttle missions, we would never have had a Hubble Space Telescope at all – the telescope as initially launched had a flaw in its optics that required a human mission and on-orbit servicing to correct. A human spaceflight: the difference between the creation of the premier scientific instrument of our time and an orbiting paperweight.
Seife believes NASA is dishonestly trying to justify its existence on the basis of a search for extraterrestrial life. Although I partly agree with this complaint, in fact, this “justification” is not NASA’s doing – if he wants to indict someone for advocacy of this crusade, he should begin with Carl Sagan and thirty years of Star Trek re-runs. NASA latched onto the Quest for Life Elsewhere meme because they thought it would justify funding for human missions to Mars – and it has remained their fantasy destination for well over 50 years. And this brings us to Seife’s real beef – those damnable, worthless human space missions. Seife is enamored of the agency’s many robotic missions, claiming they do more science for less money, but nowhere in his piece does he back up his assumption that science is the only (or even the principal) objective for a national civil space program.
I have discussed the scientific value of human spaceflight previously. The claim that robotic spaceflight is superior to the human variety usually relies on an alleged cost-benefit argument. This equation assumes that “science return” can be measured, usually by some quasi-quantitative assessment, such as the number of papers published or Nobel prizes awarded. Unfortunately, science return is difficult to quantify. Typically, there’s a lag time before we recognize the true significance of some results and understand exactly how and where they fit into a broader pattern of knowledge and utility. A human’s ability to contextualize and adapt to their surroundings gives them superior abilities and unprecedented flexibility that enriches scientific return.
Let us recall the scientific buzz about the Apollo missions in the decade after the program ended. Quite aside from the dismissal of the entire effort by many in the chattering classes (“All we got from the Moon was a box full of rocks!”), many scientists claimed that the Apollo explorations had been all but worthless. The carping began even before Apollo 11 touched down on the lunar surface; with limited time and mobility, the crew had to hurry through a sample collection routine that was strictly choreographed, thus limiting the documentation and study of the environment of the samples. Physicist Ralph Lapp wrote before the lunar landing that after Apollo had achieved its goal of landing a man on the Moon, the human program should be terminated and Apollo hardware “reserved for future unmanned missions to the planets” (exactly how one would use an Apollo Command Module to explore Jupiter was left as an exercise for the student). Famous-for-being-an-ex-astronaut Brian O’Leary whined that science was being given short shrift in the planning for the Apollo missions. Even Eugene Shoemaker, one of my personal heroes and the founder of modern planetary science, complained about the poor mission planning that resulted in a less-than-optimum system for the exploration of the lunar surface.
But then came a decade of detailed study of the returned data and samples. The science from that effort revolutionized not only planetary science, but influenced other branches of science as well, most notably, the connection between extinctions in the fossil record of Earth and asteroid impact. We now think that impact may be one of the principal drivers in the evolution of life –massive ecological voids are created by impact catastrophes. These voids are then filled by rapid speciation and the emergence of new life groups. Impacts appear to serve the same function for evolution that wildfires serve for forest growth – a periodic “wiping of the slate” to permit new growth. This view of the evolutionary process was barely imagined prior to the advent of evidence for impact-induced extinctions. Such recognition came as a result of the study of Apollo lunar samples and the need to understand the physical and chemical effects of hypervelocity impact.
Needless to say, such a scientific advance was not anticipated, either before or even in the immediate aftermath of the Apollo program. On a very basic level, the value of scientific exploration is not quantifiable. When a scientist or a journalist presumes to speak for the scientific community as whole and declares that some science is “worthless” or “second-rate,” they are actually expressing the limitations of their own imaginations and expertise, not necessarily the true value of an experiment or program. In Seife’s article, he claims that the science performed on the International Space Station is published only in “third or fourth tier journals.” The fact is, we don’t know what (if any) science done on ISS will ultimately be of lasting or revealing value. That’s the beauty of scientific research – sometimes, disfavored ideas turn out to have the most profound implications.
Of course, there’s no guarantee that any of the ISS science will turn out to be significant. But that is actually beside my main point: those who critique human spaceflight by claiming it is not scientifically worthwhile on a cost-effectiveness basis do not know (quite literally) what they are talking about. With no leadership and direction, these “controversies” have produced community in-fighting and contributed to the deconstruction the U.S. space program. Whether crafted this way by design or not, it has had the same effect.
The current National Academy Committee on Human Spaceflight is reportedly studying the rationale and benefits of humans in space. I hear on good authority that this panel is struggling with their task. I find it particularly distressing that they are having difficulty comprehending the idea that human missions contribute significantly to scientific advancement – in some cases in totally unexpected directions. It makes me wonder who they are listening to – Seife perhaps? If such is the case, they need to solicit and include more diverse – and expert – opinions.