Since the launch of Sputnik in 1957, humanity has deployed several space stations in orbit around the Earth, the most notable being the International Space Station (ISS). There, astronauts and cosmonauts from the US, Russia, the European Union, Canada, and Japan work together on a myriad of experiments and projects on human biology, physics, medical research, astronomy, and meteorology. For the last 12 years, humanity has maintained a continuous presence on the ISS, and by extension, a continuous presence in space.
However, as we look towards the settlement of outposts and colonies on the Moon and on Mars, a peculiar issue arises. Out of the more than 500 individuals who have reached Earth's low-orbit, every single one of them was born and raised on Earth. With the distances between planets and solar systems, it may become necessary to rely on natural population growth to sustain colonies and outposts, whether on a planet, a moon, or a colony in orbit. In fact, on extended voyages that could span generations before the destination is reached, natural reproduction may be the only way for a crew to survive, albeit without the original voyagers. But is it possible to have a baby in space? What would it look like? Is it even possible to conceive one? And if it is fundamentally possible, how would one engage in the "act" while under zero-g?
Practical Problems with Zero-G
The term zero-g is often misinterpreted to mean "zero gravity", but the two are not synonymous. "Zero gravity" refers to the lack of a gravity on an object. On the International Space Station, the astronauts are weightless. However, there is still a gravitational pull on the ISS from the Earth; there is still gravity in effect.
"Zero-g" refers to the lack of any gravitational force on an object. On Earth, all objects, ignoring air friction, fall down to the Earth with an acceleration of 9.81 m/s2 (≈32.17 ft/s2), but during free fall one feels weightless. This remains true on the International Space Station. The astronauts are falling, but the speed at which they travel around the Earth, 28,000 km/h (17,000 mph), keeps them in orbit.
Because of this falling, the astronauts on the ISS feel weightless and they float around. This, of course, makes many tasks much more difficult to perform. The lightest push or shove can make a person fly away in the opposite direction. Even hugging can be difficult without the use of special clothing. But if even doing menial tasks in zero-g is difficult, what about sex?
In order to understand if it is possible to have a baby in space, it is necessary to understand the mechanics of sexual intercourse in a micro-gravity environment. While many may fantasize about doing the act in space, and yes, there have been "scenes" in "movies" where a simulated zero-g environment was used, there is no research or examples of sexual encounters between astronauts in orbit. One could assume it would be very different. Without gravity, the possibilities are endless. Imagine all the new positions and the thrill! However, in reality, where a simple push or thrust can send the two flying apart, relations of a sexual nature in space can be quite difficult.
Astronauts engaging in physical exercise via anchoring systems
A simple solution to this problem already exists drawn from other forms of exercise in space. In order to stay fit, astronauts strap and anchor themselves to the walls of the space station. This allows them to jog, for example, without any major difficulties. Sexual encounters can be facilitated in the same manner, although this may take away from some of the intimacy, unless you are into that kind of thing. However, while the actual act of sex may be possible in zero-g, it is not the only step in the development of a baby.
Conception in Space?
While there have been rumors circulating that both NASA and the Russian Federal Space Agency have done research on coitus in a zero-g environment, both parties deny these allegations. As such, there is little to no published research on the reproductive capabilities of humans in space. There are, however, research and studies on the reproductive processes of plants and animals in zero-g.
In a study by the University of Montreal, researchers looked into the reproductive methods of plants in environments of high and low gravity. Plants were chosen for this study as the sperm cells in plants are delivered to their "egg" via a cylinder-like tool. The shape and function of this tool allowed researchers to make parallels between plants and our own reproductive process.
A pollen cell during fertilization
With the use of fast developing pollen cells, the male reproductive cell in plants, researchers were able to observe the effects of different gravities on the plant cells very quickly. This was done at facilities provided by the European Space Agency. Microgravity environments, like those on a spacecraft, were simulated by using a three-dimensional clinostat, a machine that rotates objects in a way that spreads the effects of gravity in every direction, thus creating weightlessness. A centrifuge was used to mimic environments of hypergravity, such as those you would find on a massive planet.
What they found was that gravity changes negatively affected these pollen cells. The cells experienced problems due to "traffic" in the intracellular systems, the networks that coordinated communication, transport, and growth. In addition, the changes in gravity affected the usually precise and coordinated cell growth, becoming, for example, in microgravity, erratic and unstable. While these were only plant cells, our cells are similar enough that these issues may happen to an embryo or a fetus developing in orbit.