A scene from "For All Mankind" shows a fictional Martian city from above. (Credit: Sony Pictures / Apple TV+)
Elon Musk and Jeff Bezos may harbor multibillion-dollar dreams of sending millions of people to live on Mars, on the moon and inside free-flying space habitats — but a newly published book provides a prudent piece of advice: Don’t go too boldly.
It’s advice that Kelly and Zach Weinersmith didn’t expect they’d be giving when they began to work on their book, titled “A City on Mars.” They thought they’d be writing a guide to the golden age of space settlement that Musk and Bezos were promising.
“We ended up doing a ton of research on space settlements from just every angle you can imagine,” Zach Weinersmith says in the latest episode of the Fiction Science podcast. “This was a four-year research project. And about two and a half years in, we went from being fairly optimistic about it as a desirable, near-term likely possibility [to] probably unlikely in the near term, and possibly undesirable in the near term. So it was quite a change. Slightly traumatic, I would say.”
We’ve spent a few articles on Universe Today talking about just how difficult it’s going to be to travel to other stars. Sending tiny unmanned probes across the vast gulfs between stars is still mostly science fiction. But to send humans on that journey? That’s just a level of technology beyond comprehension.
For example, the nearest star is Proxima Centauri, located a mere 4.25 light years away. Just for comparison, the Voyager spacecraft, the most distant human objects ever built by humans, would need about 50,000 years to make that journey.
I don’t know about you, but I don’t anticipate living 50,000 years. No, we’re going to want to make the journey more quickly. But the problem, of course, is that going more quickly requires more energy, new forms of propulsion we’ve only starting to dream up. And if you go too quickly, mere grains of dust floating through space become incredibly dangerous.
Based on our current technology, it’s more likely that we’re going to have to take our time getting to another star.
And if you’re going to go the slower route, you’ve got a couple of options. Create a generational ship, so that successive generations of humans are born, live out their lives, and then die during the hundreds or even thousands of year long journey to another star.
Artist’s impression of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri. The double star Alpha Centauri AB is visible to the upper right of Proxima itself. Credit: ESO
Imagine you’re one of the people destined to live and die, never reaching your destination. Especially when you look out your window and watch a warp ship zip past with all those happy tourists headed to Proxima Centauri, who were start enough to wait for warp drives to be invented.
No, you want to sleep for the journey to the nearest star, so that when you get there, it’s like no time passed. And even if warp drive did get invented while you were asleep, you didn’t have to see their smug tourist faces as they zipped past.
Is human hibernation possible? Can we do it long enough to survive a long-duration spaceflight journey and wake up again on the other side?
Before I get into this, we’re just going to have to assume that we never merge with our robot overlords, upload ourselves into the singularity, and effortlessly travel through space with our cybernetic bodies.
For some reason, that whole singularity thing never worked out, or the robots went on strike and refused to do our space exploration for us any more. And so, the job of space travel fell to us, the fragile, 80-year lifespanned mammals. Exploring the worlds within the Solar System and out to other stars, spreading humanity into the cosmos.
Artist’s impression of astronauts exploring the surface of Mars. Credit: NASA/JSC/Pat Rawlings, SAIC
Come on, we know it’ll totally be the robots. But that’s not what the science fiction tells us, so let’s dig into it.
We see animals, and especially mammals hibernating all the time in nature. In order to be able survive over a harsh winter, animals are capable of slowing their heart rate down to just a few beats a minute. They don’t need to eat or drink, surviving on their fat stores for months at a time until food returns.
It’s not just bears and rodents that can do it, by the way, there are actually a couple of primates, including the fat-tailed dwarf lemur from Madagascar. That’s not too far away on the old family tree, so there might be hope for human hibernation after all.
In fact, medicine is already playing around with human hibernation to improve people’s chances to survive heart attacks and strokes. The current state of this technology is really promising.
They use a technique called therapeutic hypothermia, which lowers the temperature of a person by a few degrees. They can use ice packs or coolers, and doctors have even tried pumping a cooled saline solution through the circulatory system. With the lowered temperature, a human’s metabolism decreases and they fall unconscious into a torpor.
But the trick is to not make them so unconscious that they die. It’s a fine line.
The results have been pretty amazing. People have been kept in this torpor state for up to 14 days, going through multiple cycles.
The therapeutic use of this torpor is still under research, and doctors are learning if it’s helpful for people with heart attacks, strokes or even the progression of diseases like cancer. They’re also trying to figure out if there are any downsides, but so far, there don’t seem to be any long-term problems with putting someone in this torpor state.
A few years ago, SpaceWorks Enterprises delivered a report to NASA on how they could use this therapeutic hypothermia for long duration spaceflight within the Solar System.
Currently, a trip to Mars takes about 6-9 months. And during that time, the human passengers are going to be using up precious air, water and food. But in this torpor state, SpaceWorks estimates that the crew will a reduction in their metabolic rate of 50 to 70%. Less metabolism, less resources needed. Less cargo that needs to be sent to Mars.
Credit: SpaceWork Enterprises, Inc
The astronauts wouldn’t need to move around, so you could keep them nice and snug in little pods for the journey. And they wouldn’t get into fights with each other, after 6-9 months of nothing but day after day of spaceflight.
We know that weightlessness has a negative effect on the body, like loss of bone mass and atrophy of muscles. Normally astronauts exercise for hours every day to counteract the negative effects of the reduced gravity. But SpaceWorks thinks it would be more effective to just put the astronauts into a rotating module and let artificial gravity do the work of maintaining their conditioning.
They envision a module that’s 4 metres high and 8 metres wide. If you spin the habitat at 20 revolutions per minute, you give the crew the equivalent of Earth gravity. Go at only 11.8 RPM and it’ll feel like Mars gravity. Down to 7.8 and it’s lunar gravity.
Normally spinning that fast in a habitat that small would be extremely uncomfortable as the crew would experience different forces at different parts of their body. But remember, they’ll be in a state of torpor, so they really won’t care.
Credit: SpaceWork Enterprises, Inc
Current plans for sending colonists to Mars would require 40 ton habitats to support 6 people on the trip. But according to SpaceWorks, you could reduce the weight down to 15 tons if you just let them sleep their way through the journey. And the savings get even better with more astronauts.
The crew probably wouldn’t all sleep for the entire journey. Instead, they’d sleep in shifts for a few weeks. Taking turns to wake up, check on the status of the spacecraft and crew before returning to their cryosleep caskets.
What’s the status of this now? NASA funded stage 1 of the SpaceWorks proposal, and in July, 2016 NASA moved forward with Phase 2 of the project, which will further investigate this technique for Mars missions, and how it could be used even farther out in the Solar System.
Elon Musk should be interested in seeing their designs for a 100-person module for sending colonists to Mars.
Credit: SpaceWork Enterprises, Inc
In addition, the European Space Agency has also been investigating human hibernation, and a possible way to enable long-duration spaceflight. They have plans to test out the technology on various non-hibernating mammals, like pigs. If their results are positive, we might see the Europeans pushing this technology forward.
Can we go further, putting people to sleep for decades and maybe even the centuries it would take to travel between the stars?
Right now, the answer is no. We don’t have any technology at our disposal that could do this. We know that microbial life can be frozen for hundreds of years. Right now there are parts of Siberia unfreezing after centuries of permafrost, awakening ancient microbes, viruses, plants and even animals. But nothing on the scale of human beings.
When humans freeze, ice crystals form in our cells, rupturing them permanently. There is one line of research that offers some hope: cryogenics. This process replaces the fluids of the human body with an antifreeze agent which doesn’t form the same destructive crystals.
Scientists have successfully frozen and then unfrozen 50-milliliters (almost a quarter cup) of tissue without any damage.
In the next few years, we’ll probably see this technology expanded to preserving organs for transplant, and eventually entire bodies, and maybe even humans. Then this science fiction idea might actually turn into reality. We’ll finally be able to sleep our way between the stars.
By popular request, Isaac Arthur and I have teamed up again to bring you a vision of the future of human space exploration. This time, we bring you practical construction tips from a pair of Type 2 Civilization engineers.
To make this collaboration even better, we’ve teamed up with two artists, Kevin Gill and Sergio Botero. They’re going to help create some special art, just for this episode, to help show what some of these megaprojects might look like.
Robotic construction of the proposed "Stairway to Mars", a concept for fuelling spacecraft on their way to other destinations. Credit: Anna Nesterova art
Any road trip requires rest stops to refuel and rest. That’s especially true of planetary exploration, as it would take months between destinations. In that spirit, here is a new concept for “Mars truck stops” from the Space Development Steering Committee, which they call “Stairways to Mars.”
For those who aren’t aware, the committee is a coalition of space advocates. Included in the group are the heads of the National Space Society, the Space Frontier Foundation, and the Mars Society, SDSC said, as well as a list of past astronauts, high-ranking NASA employees and others. (The founder is Howard Bloom, who was a former visiting scholar at New York University’s graduate psychology department, among other positions.)
So how would a Mars truck stop work? In a nutshell, this is what SDSC proposes:
– Beams are constructed in space “just like a giant erector set”, according to a statement from John Strickland, SDSC chief analyst. This would be accomplished using “robots on rails” that could build the first part, then “extend … its own rails along the beam as it goes.”
– Solar panels are added on to the beam to provide power;
– Components are then added according to need. Pictures from SDSC show items such as fuel tanks on the truck stop. If ambitions soared even higher, the concept could even be built upon to make a larger space colony modelled on “O’Neill colonies”, as shown below.
A space colony under construction using a concept from the Space Development Steering Committee. The image shown above has a deck 1,000 feet wide, as well as robots that carry cargo and beams for parking spots. Credit: Anna Nesterova art
It should be emphasized that this is a concept, with no funding or firm plans yet, but for what it’s worth the committee says it could move quickly. “These plans are budgeted to cost LESS than the current NASA program for our next step in space — the $40 billion Space Launch System and Orion Capsule. What’s more, the first steps of the Stairway to Mars are achievable in three years,” the committee writes.
One possible location for this kind of truck stop would be at the Earth-Moon L1 Lagrange point, or a spot in space where gravities from different bodies approximately equal each other out and allow an object to hover in place. Lagrange points are already used for several space missions, including the Planck telescope that was just decommissioned.
What do you think of the concept? Let us know in the comments.
An artist's conception of future Mars astronauts. Credit: NASA/JPL-Caltech
We all love space here and we’re sure, given that thousands of people applied for a one-way trip to Mars, that at least some of you want to spend a long time in a spacecraft. But have you thought about the bacteria that will be going along with you?
If you don’t feel too squirmy to read on, understand this: one type of bacteria grown aboard two shuttle missions ended up being bigger and thicker than control colonies on Earth, new NASA research shows.
Two astronaut crews aboard space shuttle Atlantis grew colonies of bacteria (more properly speaking, biofilms) on behalf of researchers on Earth. Most biofilms are harmless, but a small number could be associated with disease.
Biofilms were all over the Mir space station, and managing them is also a “challenge” (according to NASA) on the International Space Station. Well, here’s how they appeared in this study:
“The space-grown communities of bacteria, called biofilms, formed a ‘column-and-canopy’ structure not previously observed on Earth,” NASA stated. “Biofilms grown during spaceflight had a greater number of live cells, more biomass, and were thicker than control biofilms grown under normal gravity conditions.”
Astronauts strut their superpowers on the final shuttle mission, STS-135. Turns out bacteria acquire some super-growth in microgravity, too. Credit: NASA
The type of microorganism examined was Pseudomonas aeruginosa, which was grown for three days each on STS-132 and STS-135 in artificial urine. That was chosen because, a press release stated, “it is a physiologically relevant environment for the study of biofilms formed both inside and outside the human body, and due to the importance of waste and water recycling systems to long-term spaceflight.”
Each shuttle mission had several vials of this … stuff … in which to introduce the bacteria in orbit. The viles included cellulose membranes on which the bacteria could grow. Researchers also tested bacteria growth on Earth with similar vials. Then, all the samples were rounded up in the lab after the shuttle missions where the biofilms’ thickness, number of cells and volume was examined, as well as their structure.
This is still early-stage work, of course, requiring follow-up studies to find out how the low-gravity environment affects these microorganisms’ growth, according to lead researcher Cynthia Collins from the Rensselaer Polytechnic Institute. Metabolism and virulence are what the scientists are hoping to learn more about in the future.
Samples of bacteria Pseudomonas aeruginosa. Credit: NASA
“Before we start sending astronauts to Mars or embarking on other long-term spaceflight missions, we need to be as certain as possible that we have eliminated or significantly reduced the risk that biofilms pose to the human crew and their equipment,” stated Collins, an assistant professor in the department of chemical and biological engineering.
While this research has more immediate implications for astronaut health, the researchers added that better understanding the biofilms could lead to better treatment and prevention for Earth diseases.
“Examining the effects of spaceflight on biofilm formation can provide new insights into how different factors, such as gravity, fluid dynamics, and nutrient availability affect biofilm formation on Earth. Additionally, the research findings could one day help inform new, innovative approaches for curbing the spread of infections in hospitals,” a NASA press release stated.
If you’re not feeling too itchy by now, you can read the entire study in an April issue of PLOS ONE.
