Essay: Lie Back and Think of Science

The many unknowns humanity must explore before having children on Mars

As the years and technology tick on, we’re finally on the threshold of making reality out of what was once science fiction: We’re heading to Mars.

With the colonization project Mars-One offering the chance for a one way trip to healthy individuals world-wide, we’re now faced with questions of how we will make our new life on a barren and inhospitible planet.
What will an average day on Mars be like? What will future Martians do for entertainment? How will they relax?

There will be difficult trials to overcome, many of which we have not anticipated yet. We’ll be building a world from scratch: mining materials, milling them, consuming them, and recycling them. Anything that can’t be derived from the planet itself will have to be shipped–with a several-hundred-thousand dollar price tag.

It is no surprise to us that a trip to Mars will be one vast experiment in human endurance and adaptability. It is just the sort of challenge that has driven explorers of the past to venture out in search of new land, and it is a magnet to us now. Although we don’t yet know if this colonization will be a one-time affair or an ongoing mission, we do know that humans WILL endeavor to reach the stars. Mars is an intrinsic step in that process.

Whether Mars remains an important stop on the path to the rest of the galaxy, however, will depend on its human inhabitants. In order to sustain an outpost there indefinitely, we will need to consider making Mars into a permament settlement, and making little Martians to succeed us and our goals. We’re not looking at a possibility, but an inevitability. Without children, future colonists won’t be able to build and maintain a viable community.

However, children aren’t an option for us just yet. Before they can be, we’re going to have to surmount obstacles that have no easy solutions on Earth, much less 140,000,000 miles away from the nearest pediatrician.

Future mothers and fathers will have to cope with radiation, bone loss, and the affects of lower gravity. They’ll have to deal with cramped, not-particularly-private conditions, and they’ll have to deal with raising children in an environment unlike any humans have ever lived in. They’ll have to make difficult decisions regarding their health, and the potential health of their offspring. They’ll have to learn new tricks to overcome the problems of childbearing away from Earth, and pass those on to future explorers.

They’ll perservere…eventually.

However, there is a lot they’re going to have to face before they do.


Radiation and Reproduction

The biggest obstacle in children on Mars may be the transit to Mars.

In the seven months we’ll be in space, much of our shielding against the hazards of stellar radiation will be provided by huge water tanks. However, these will slowly empty as we approach our destination, progressively stripping away our protection and exposing us to harmful energy.

While the amount of radiation received on a one-way trip will be well below accepted levels for an astronaut, it is still a great deal more than the average person on Earth would be exposed to. We will be in danger of SPE’s–Solar Particle Events–which are storms of unpredictable energy emitted from the sun. Also on the plate are heavy ions and other types of radiation which Earth’s magnetic field would normally block.

While there have been significant studies conducted on the effects of radiation and reproduction, these studies have been on more common types of radiation such as x-rays, gamma rays, and beta rays. In other words, we do know that astronauts would have to be exposed to a far greater dose of most types of radiation than we will be encountering in order to be rendered unfertile. What we do not know is how other types of radiation will affect us and our reproductive organs.

Even on Mars, we’re going to have to monitor radiation levels during pregnancy to ensure a minimum of exposure. Mothers will likely need to avoid long trips outside of heavily shielded structures, as fetuses have a high sensitivity to radiation from 8 to 25 weeks of gestation, and are particularly sensitive between 8 and 15 weeks. If not carefully monitored, these exposures could lead to many different types of malformation, from severe mental retardation to growth and central nervous system abnormalities.

It’s going to be a long nine months for Martian moms, but even with proper shielding there is still an increased risk from just having made the trip to Mars. Should any of the above problems occur, they will also be harder to mitigate without access to many of the care systems that are available on earth.

This places a particularly heavy burden on our future parents. Knowing that there is a higher probability of birth defects and a lower likelihood of assistance if such defects should occur, the decision to have a child may easily become a weighted debate.


Gravity and Development

It won’t just be radiation that will be adding to the possibility of malformation, either. At the moment, gravity’s effect on developing embryos is still being researched. Scientists have started to observe that there are some functions that need gravity in order to occur. However, with experiments on animals in space being difficult to isolate for only the gravity factor (without said animals undergoing stress from a change-in-environment), it is difficult to say for absolute certain which functions those are.

To further complicate the subject, we’ve done experiments in microgravity (space) and in normal gravity (Earth), but we have not experimented at 1/3rd gravity to see how embryos develop on Mars.

This leaves us with a large, large number of unknowns.

All we can do at this point is look at what we’ve learned in space and what we’ve learned on earth and assume that Mars will be somewhere in the middle. Where in the middle it will fall, however, is yet to be seen.

If we’re looking at the data we’ve gained from space, we’re in for a rough ride. To start with, the act of procreation itself is more difficult in microgravity. Humans tend to perspire more in space, making it less appealing to interact and more difficult to stay in contact. The lack of the Earth’s greater mass holding us in place also means we must exert a great deal more effort ourselves to make the experience an enjoyable one.

Assuming that we’ll be able to overcome that problem, there’s still nine months of potential mishaps yet to come.

The starting point looks promising. Experiments with rats and mice done in space have shown that microgravity does not have a large negative impact on the initial functions of either the egg or the sperm. In fact, sperm even seem to perform better in a lower gravity situation (even if there seem to be lower sperm counts overall), and cell divisions in the resulting embryo have gone well.

After that point, however, the benefits of lower gravity seem to disappear. In those same rats, there is a noticeably lower rate of embryos implanting in the uterus, and a noticeably lower rate of successful development moving forward. There have been less baby rats born from the embryos that are conceived in space than from the normal earth control embryos, and when observing the female rats a number of those embros appear to have been reabsorbed. Even when embros developed in space are implanted in rats on Earth, only about 1/3 of those actually mature fully.

Tests with reptiles and birds show similar results: that while fertilization and later fetal development can occur in microgravity conditions, even a single day of space exposure to early embryos can be hazardous.

Thus, it is highly likely that space pregnancy in humans will not be in our foreseeable future…

…but how will the reduced gravity on Mars affect an unborn baby?

At this point, we still do not know.

However, it does seem like a lower gravity will have some impact on childbearing.


Bone Loss and pregnancy

A lack of gravity will also have an impact on our future mother’s bones.

For every month spent in space, an astronaut loses 1-2% of his or her bone mass, with noticeable changes starting after only a few days. Since a trip to Mars takes around seven months, we will be facing up to a 14% loss of our bone mass to this bone de-mineralization. With bones taking longer to recover as we age, many astronauts will find that they never fully reach the same pre-flight density. This loss of bone density in transit presents an increased risk to the mother while carrying.

Considering that an average fetus will borrow about 30g of calcium from his/her mother’s reserves and/or skeleton, it is easy to see where a potential source of danger for Martian Moms arises. Women who breastfeed can lose another 3-5% of their bone mass, putting their total potential mass lost after spaceflight (14%) and gestation(~1%) at almost 20%. This loss might exacerbate already common pregnancy-related bone problems like a separated pubic symphysis (a narrow section of cartilage joining the left and right pelvic girdle which loosens during pregnancy) or a fractured coccyx (the ‘tailbone’ which can be broken by pressure from the baby’s head during childbirth.)

Fortunately, its not all bad news. Some of those same pregnancy studies have concluded that in many cases having a child is actually beneficial for bone regeneration, and that women who have had multiple pregnancies (of at least 28 weeks) have enjoyed greater bone density afterward and less risk of fracture than those who have not.

However, first pregnancies will be particularly difficult on Mars, which could further limit one’s freedom to move around during those long nine months. Because of this, a Martian mother is going to have to be firm in her resolve to have a child in the face of these risks to her body, and she’s going to have to be meticulously careful to keep herself safe.


A Martian Community

Thankfully, she will not be alone. It has been said that it takes a village to raise a child, and in an environment where there is no escape from one’s next-door neighbors this is going to prove doubly true.

Having a baby on Mars may well be the decision of not just the mother and father, but of the entire enclosure that they live inside. Additional food will need to be planned in advance to accomodate a growing child, additional supplies will need to be saved, oxygen ratios will need to be monitored, and living quarters will eventually need to be found for the new member of the community.

There will be psychological burdens as well. Assuming that a healthy Martian child is born without any of the problems brought about by lower gravity or radiation, we are still going to have to face the prospects of education and entertainment and socializing, all of which will be difficult in a severly remote outpost. Close quarters and small, isolated populations may inadvertantly result in everyone taking part in parental duties, regardless of whether they are the parents or not.

To make it even more stressful, the first children born on Mars will be a subject of intense media scrutiny. All decisions made by the colony will be weighed and measured by people still on Earth, which could provide either support or confrontation.

In addition to the difficulty of raising children on Mars, we also will be faced with limiting them to a single world. Although the community at large will have long ago committed their lives to making Mars their home, any children born there will not have that same choice. For the foreseeable future they will be stuck, and will likely not have the physical capability to visit to the much heavier gravity of Earth even should technology eventually allow them to.

However, there is no way to tell how they might feel about this now. It could be a source of contention, but it could also be a source of inspiration for future generations of Martians who want to make the next big step.

It is one more consideration at the end of a long list of considerations. By the point that we’ve overcome the effects of gravity, radiation, bone loss, and stress to make the first generation of true Martians, it may not even matter. Human beings have been expanding into new and frightening territories since we became human, and we’ve not only survived but thrived in them.

However, when the time comes for the first Martian couple to have a child there will still be many variables to contend with. This endeavor will be an experiment in our endurance and our resolve, because there is no way to know what having a baby on Mars will be like…except through having a baby on Mars.

The time might not be right now (and it won’t be right for this author in her lifetime), but there will be a point where we understand the risks well enough to try for the reward. We’ll need to know, eventually, what it is like to bring humanity to Mars so that we can start planning for what lies beyond Mars. We are going to have to take that leap together.

For our race.

For ourselves.

And, of course, for science.



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