Is human exploration beyond low Earth orbit a thing of the past? Will space tourism profit and grow in low Earth orbit while the rough exploration of space beyond the Moon will continue to be done via robotics?
These questions go to the heart of “The End of Astronauts: Why Robots Are the Future of Exploration,” a thought-provoking new book co-authored by astrophysicists Donald Goldsmith and Martin Rees.
While such arguments are not necessarily new, the authors present a few new salient points that bear repeating here.
—- Human space travel remains dangerous.
High-energy solar and galactic particles are common throughout the solar system. Beyond Earth’s Van Allen radiation belts, astronauts are particularly vulnerable to radiation from these particles.
For every month in space, human bone density can decrease by up to 1.5% in weight-bearing areas of the body such as the hips and knees. Astronauts spending six months en route to Mars would receive at least 60% of the total radiation dose recommended for a full career, the authors note. The journey home would push them over the edge even without a sudden increase in storms or solar flares, they note.
—- Unlike human space exploration, non-human robotic explorers have safely and efficiently reached the outer edges of our solar system.
“Since its inception in 1958, NASA has spent approximately 60% more on human exploration than on robotic investigation of the cosmos,” the authors write. “It should be noted that human exploration of space has so far only extended to the Moon…”
—- Space telescopes do not need to be usable by humans.
Although the Hubble Space Telescope would not have been operational without the ability to save it from what Goldsmith and Rees call “an otherwise fatal manufacturing defect”, they note that the director of the Space Telescope Science Institute, which operates the Hubble ” a said the total cost of the five astronaut repair missions would have paid for the construction and launch of seven replacement telescopes.
It is unclear whether this would be the case, given the rising costs of instrumentation and space observatories in general. But the point is well taken. And that may be one of the reasons why Hubble’s follow-on observatory, NASA’s James Webb Space Telescope (JWST), was never meant to be maintained by human astronauts, at least. .
From its current solar orbit about a million miles from Earth, the James Webb is currently beyond the range of a crewed service mission. But so far it has proven to be on track for full science operations due to begin this summer.
—- Man-made platforms for space colonies would hardly be Valhallas.
Artists often portray space colonies as exciting and appealing, resembling a vacation spot or another fulfillment of our hopes for a near-perfect environment, write Goldsmith and Rees. But the authors note that this is unlikely to resemble the reality of such space colonies being built in interplanetary space. They note that there will be great difficulties and dangers in maintaining such huge man-made structures in space, as well as the technical challenges associated with their construction.
—- But space platforms would potentially allow billions of people to live in space.
As Goldsmith and Rees point out, “in his 1997 book ‘Mining the Sky’, cosmochemist John Lewis lamented that “so long as the human population remains as pitifully small as it is today, we will be severely limited in what we Lewis pointed out that “human intelligence is the key to the future…Having one Einstein, one da Vinci, one Bill Gates is not enough”.
The implication is that maximizing our human potential might require increasing the human population a hundredfold. Space platforms would offer humans a sustainable way to increase our numbers and thus “roll the dice” so that genies become more common. Who knows if such a scheme would work? Instead, it would just be easier to artificially rearrange our brains to make these once-in-a-lifetime geniuses more mundane than we could ever imagine.
This whole argument is somewhat tangential to the book’s focus on why robots should prevail in space, at least for now.
Goldsmith and Rees argue for robotics over astronauts, at least in the short term. But let’s hope that in 100 years, time and technology will allow us to have both robust human interplanetary spaceflight and advanced robotic space science and exploration.
In the short term, however, it probably makes sense to emphasize exploration of the solar system via robotics, as national space agencies have done brilliantly for the past 65 years. It’s truly amazing and all that has been accomplished with so little dollars.
In time, hopefully there will be a meeting that there will be some sort of fusion between the kind of robotics that can complement our human aspirations to travel through interstellar space in ways that are incomprehensible at present. .