The human spaceflight equation
by Eric R. Hedman
|It is no wonder, given the history of life on this planet, that some of us consider it normal that we should migrate to places we can reach off this planet.|
Recently a Viking settlement was found in Point Rosee, New Foundland. It is 500 kilometers southwest from the only other Viking settlement found in the Americas. It was found using near infrared space imaging, which detected the remnants of sod wall buildings. Evidence of an iron smelting furnace was also found. The Vikings, in essence, took advantage of in situ resource utilization (ISRU) in this settlement. Among the items they manufactured from local resources were nails to hold their long boats together.
Humans, like all life forms throughout history, try to expand into new territories. It isn’t all members of each species that try to explore and settle new territories. Some have a stronger instinct for wanting to see what is over the next hill, around the next bend in the river, or on the next planet than others. Without this instinct to diversify into new territories, a species is at greater risk of extinction from threats such as famine, disease, predators, and drought.
The simplest forms of life move into new territories by methods that are mostly beyond their control. A bacterium may be carried into a new territory by wind or currents or being stuck on an animal. As species evolved into multicellular organisms and developed nervous systems, there started to be intelligent decisions involved in where to go. A worm goes to where it thinks there is food based on what its senses tell it is around it. Some bird species seasonally migrate across oceans to find nesting grounds and food. Whales and large fish, including tuna and marlin, travel thousands of kilometers in the world’s oceans for similar reasons.
Humans are the first species to make the conscious decision to leave the planet. It is no wonder, given the history of life on this planet, that some of us consider it normal that we should migrate to places we can reach off this planet. It is within our nature that some of us want this to happen. No matter how complicated the decision to move into new environments become, it all comes back to instincts that help the survival of the species.
When Leif Eriksson headed to the New World a thousand years ago, he did so because he was banished from existing Viking settlements given his bad habit of regularly killing people. It was a trait he learned from his father, Erik the Red. He, along with his band of followers, headed west to find a new territory. According to the Viking Sagas, a written history from a thousand years ago that now has some archaeological evidence supporting its narrative, the Vikings ran into natives and initially traded with them. Over time relations turned hostile and the natives with superior numbers encouraged Leif Eriksson and his band of Vikings to head back to settled territories in Greenland, Iceland, and finally back to Norway.
When either humans or a strain of bacteria, or any lifeform in between, moves into a new territory, the same basic factors come into play that determines if they stay. Is there sufficient food to survive and grow? Are the environmental factors hospitable enough for survival? Is there air and water available? Is the temperature within an acceptable range? Is there anything hostile like the irked natives that drove the Vikings away from Eastern Canada or antibodies that can kill colonizing bacteria or predators that will wipeout an immigrant invasive species?
|Now, NASA is starting to fund development of a deep space habitat. It is part of NASA’s “Journey to Mars.” But many members of the public don’t know why we are going, and if we are going, if it is to stay.|
Life throughout all its layers has repeated patterns as it has continued to evolve. These patterns repeat because they are successful. Life evolves and advances with fits and starts and spreads out to wherever it can successfully survive. I see no difference when we take steps to worlds beyond our own. That is one reason I believe that when we either return to the Moon and or go on to Mars we need to see if we can go to stay. It is in our nature to settle new environments. It is a characteristic of all species that have survived. The rules of evolution apply to us as much as they do to the single cell creatures that preceded us.
A couple of years ago I read Charles Darwin’s On the Origin of Species. It can be challenging to follow the logic laid out in the pages of the book. I had to go back and forth to reread many pages to understand the conclusions Darwin had drawn. The way Darwin pieces together his reasoning and his evidence to back it up has been invaluable to the advancement of science. His reasoning is why I think about the need to explore and colonize new places the way I do. Reading this book fundamentally changed the way I look at the world.
If you are going somewhere new to stay, it affects how you plan your voyage. When most people take a job in another state, they sell their home if they own one and buy a new one at the new destination and move their possessions. If they are going to visit, though, they bring just what they need for the trip. If there is no home available at the new location that is suitable, people may stay in a hotel until their new home is built. When some of my ancestors settled in Wisconsin in the early 1850s from Norway and Sweden, they had to quickly build their own first shelters. When more people arrived, they stayed at the homes of the first settlers until they could build their own. They helped each other bootstrap a community of farms in the wilderness of west central Wisconsin.
Apollo was designed primarily to go to the Moon and visit. Building an outpost was not part of the capabilities designed into the mission architecture. The Lunar Module was barely capable of getting two astronauts to the Moon and back. It couldn’t do much more. It wasn’t designed for building and supporting an outpost.
Now, NASA is starting to fund development of a deep space habitat. It is part of NASA’s “Journey to Mars.” But many members of the public don’t know why we are going, and if we are going, if it is to stay. I think those are two reasonable things that those of us who are paying for it should know.
If the only goal on the Journey to Mars is just to prove we can get there, either NASA or the President or Congress needs to tell us why this is important enough to spend hundreds of billions of dollars. If we are going to stay, though, it also needs a justification. Does it mean we will be setting up a colony on Mars? Does it mean we are setting up a scientific outpost like we have done in Antarctica? I personally prefer that we start with the latter for a number of reasons and decide on settlement later.
|We don’t know if a child will develop properly or even be able to return to Earth if a colony becomes for any reason unsustainable. To expose a child who has no say in the matter to this risk to me is completely immoral given our current level of understanding of the issue.|
Earlier this year, Scott Kelly returned from his 340 days in orbit aboard the International Space Station. The expedition had a significant impact on his health. He said that if he hadn’t just come back from space he would have probably gone to the emergency room due to how bad he was feeling. There are many deleterious effects on the human body from long-term exposure to microgravity. We just don’t know how bad the effects would be from long-term exposure to Martian gravity, about three-eights that of Earth. Before we start a settlement there several questions relating to partial gravity effects need to be answered.
Of course, if people want to take the risk of going to Mars without addressing these issues, this is a personal decision and I believe there will be no shortage of qualified people who will want to go. Starting a settlement implies starting families and staying for good, the way my ancestors did in the Wisconsin wilderness. The problem with this is we have no idea what the effect of low gravity will have on a developing human fetus or a growing child. We don’t know if a child will develop properly or even be able to return to Earth if a colony becomes for any reason unsustainable. To expose a child who has no say in the matter to this risk to me is completely immoral given our current level of understanding of the issue.
There are many threats to human survival when we go beyond the bounds of our atmosphere. They include the hard vacuum of space, radiation, temperature extremes, toxic or caustic chemicals in regolith, dust, reliability of supporting technology, and more. To some extent we have existing or potential solutions to all of these threats. To me, the biggest unknown is how much gravity do humans need for long-term survival beyond Earth. So how do we find out?
The ISS was originally supposed to have a module with a centrifuge in it to experiment on plants and animals with varying levels of gravity. It would have been a start in finding the answers we need, but unfortunately it was canceled. There have been proposals for rotating satellites to house a colony of mice for a couple of years and several generations. This would advance our knowledge, but we still wouldn’t know if the results would scale up to larger animals and humans with longer generational cycles, unless the results were bad. If a 0.38g environment had bad effects on a couple of generations of mice, I suspect it wouldn’t bode well for humans.
Another possible place to test the effects of low gravity could be on the Moon. If we put a small base on the Moon and send crews to stay for six months to a year at a time, we would have an interesting comparison with the results from all the missions to the ISS. If lunar gravity reduced some or all of the deleterious effects, we could be fairly confident that the same would be true, if not even better, on Mars. Yet, even if those problems are reduced, we still won’t know what the potential generational effects would be on the Moon or Mars.
One of the primary purposes of the ISS has been to learn how to operate safely in space. There have been many lessons learned. One of the surprising issues has been that siloxanes, a class of chemicals commonly found in deodorants, gum up ECLSS systems. When people use deodorants on Earth, siloxanes evaporate into the atmosphere and dissipate without causing any known serious problems. In a confined environment they have to go somewhere. This isn’t something you want to go undiagnosed when you are on Mars wondering why your air quality is declining.
|I think our next research outposts, whether on the Moon or Mars, should have a primary mission similar to the ISS. Their missions should be to figure out if and how humans can survive and thrive for the long term on our nearest worlds.|
This is the type of problem you want solved before deep space missions start. Engineers have also learned which systems are durable and which systems need to be improved. We have learned how to assemble and integrate complex systems in orbit. We have also spurred the development of commercial launch systems. While the achievements of the ISS are not as dramatic as the Apollo program, or as efficiently accomplished as they could be in an ideal world, I think they have been vital in our understanding of how to move forward.
I think our next research outposts, whether on the Moon or Mars, should have a primary mission similar to the ISS. Their missions should be to figure out if and how humans can survive and thrive for the long term on our nearest worlds. Part of that is understanding the nature of these places and what resources they have to offer. In addition, we need figure out how we can live on these worlds. This also includes research on other forms of life we bring with us.
Life expectancy in much of the Western world is approximately 80 years. The typical American has children in their 20s and 30s. If we use ourselves as test subjects for generational effects of low gravity, it would take a very long time to learn if there would be any serious problems. When we want to learn the long term effects of new drugs and environmental factors we often start with animal testing. That is why I think that once either a Moon or Mars outpost is established, a module should be added to raise animals to see how they adapt. Mice would be the easiest, but primates would be a better analogy to humans. Rhesus macaques can produce a generation every three to four years. They are relatively small, requiring fewer resources than our closer cousins like chimps and bonobos, and it would not be all that long before useful data could be collected. Within five to seven years we could have reasonable but not absolute confidence in what low gravity would do to humans born and raised in the environment. That may be the time to commit to or abandon the idea of building a surface colony.
When we do send humans back to the Moon and on to Mars, part of the mission will be to explore and learn about these worlds. A bigger part of the mission will be to learn about ourselves and what we are capable of adapting to. If we learn that humans can successfully colonize the Moon or Mars, that doesn’t necessarily mean that we will. Another part of the equation is finding an economic reason to do so. If we don’t, I don’t believe a human presence on the Moon or Mars will be permanent. Earthlings will tire of paying for a colony that generates no economic or security value.
I do believe there is at least one potential opportunity on Mars that could generate tens of billions of dollars in annual revenue within a few decades after a colony is started. That idea is complex to explain, so I will leave that for a future article.
All lifeforms, including humans, have adapted to new environments. That doesn’t mean that they are successful in every attempt. Successful colonization comes from adaptability and persistence. It’s staggering to look at the challenges all life has faced as it has evolved: meteor bombardment, volcanoes, radiation, disease, temperature extremes, wind, lightning, earthquakes, world wars, nuclear accidents, and pollution, among many others. These challenges have made life tougher, more resilient, and more adaptable. Even in times of growing global instability I have become more optimistic that we will settle our solar system and eventually even beyond that. Our human challenges fit the bill for events that have prompted leaps in evolution. While extreme struggle isn’t often pleasant for the individual, it can be and has been what triggers advancement for the human race.
I don’t have a crystal ball to predict with 100 percent confidence where or how we will go next. The universe tends to throw us surprises. This instinct we have to expand and colonize is in all life. Not going and not trying is denying our fundamental nature. But if we are adaptable and persistent we will get there. Leif Eriksson and his small band didn’t come and stay permanently in the new world, but my great-great-grandparents did, as did millions of others. This instinct to explore is why life thrives. It is why we need to go. It is how the human evolutionary equation keeps resolving itself.