Quibbling with Krauss

Lawrence M. Krauss makes the argument that human exploration of space has become stagnant. After calling the ISS a "white elephant" he explains what he thinks caused the stagnation.

What happened? Why did the dream of unlimited manned space travel and a vast new universe of possibilities for humanity dry up and fizzle? The answer is relatively simple: reality prevailed. Human space travel is expensive and dangerous, and there is almost no scientific justification for it (a sobering realization for the child-turned-scientist).

I'd like to see a quantification of "almost no scientific justification.*" Whatever it is, I figure it's smaller than the obvious justification: answering the question "What are the effects of the space environment on humans?" The question admits many possible falsifiable hypothesis as answers, so the process of answering them -- which requires humans in space -- would strike me as a perfectly scientific one. *What are the units of scientific justification?** **Asterisk/italics style taken from Joe Posnanski and used without permission. Krauss may have meant "no practical justification" -- a harder charge to defend, but one I am working on addressing in part in a not-yet-completed essay, so I'll put that off for now. Instead, I'd like to defend the ISS from the charge of "white elephant." Politically, it's a example of successful international collaboration to solve a complex problem. For science, it's a lab on the frontier, allowing experiments to be conducted in an environment not available on Earth, not just the experiment of having humans live in the LEO environment, but for a wide variety of scientific research. As advanced as our robotics abilities are, I strongly doubt any set of current automated experiments or labs could match the ISS's human crew for experimental flexibility. Having human beings on board greatly simplifies experiment design and allows for new experimental hardware to be more easily repurposed or repaired. Conservatively, I put the cost of having an astronaut on station with experimental tools for 180 days at 300 million dollars. That's about 5 times the cost to NASA of launching an astronaut on the Soyuz to the station. It's really hard to imagine a robotic mission that could conduct the variety of experiments with anywhere near a human level of flexibility or productivity for that cost. Additionally, the ISS serves as an engineering prototype for those of us learning to create self contained environments, not only in space, but anywhere humanity may need them: under the oceans, in the desert or any harsh environment we may encounter (or create if the more dire climate change and post nuclear war models are correct). These are really just quibbles, though, as Krauss's main point is that the space program is insufficiently inspirational. On that, I worry, he may be correct.