Are We Serious About Sex in Outer Space? – Space Tourism and Human Conception

By Pranav Mahapatra

April 25, 2023
NASA astronauts Nicole Mann and Frank Rubio are pictured inside the seven window cupola, the International Space Station's "window to the world."

Space exploration has come a long way since the first human spaceflight in 1961, and with it, the possibilities of human expansion in space have increased.

In the upcoming years, we can expect space tourism to become more popular looking further as we approach the 2030s.

Space tourism is a rapidly growing industry that promises to offer unprecedented opportunities for human exploration and adventure.

An associated pressing and overlooked issue is the possibility of uncontrolled human conception in space, which refers to the unintended or unplanned pregnancy of space tourists or crew members during or as a result of spaceflight, this has turned into quite a serious discussion.

Uncontrolled human conception in space could have serious biological, societal, and commercial implications for the individuals involved, their offspring, and the space tourism sector as a whole.

Still, there is a lack of scientific knowledge, ethical guidance, legal regulation, and public awareness on this topic.

A green paper was recently published on Zeonodo for public consultation on the topic of “Sex in Space: Consideration of uncontrolled human conception in emerging space tourism1, aiming to fire up open debate, amid the rise of space tourism.

The Sex in Space Research Aims to Promote Open Debate

While there have been no official studies on sex in space, researchers have conducted studies on the effects of microgravity on the human reproductive system.

These studies have shown that microgravity can affect sperm motility, fertilization rates, and embryo development in animals, but the effects of microgravity on the human reproductive system are still unclear.

In the green paper, the authors quote – “It seems unrealistic to assume that all space tourism participants will abstain from sexual activities whilst in space and exposed to space environments.”

The lack of discussion on the topic poses a significant risk to the space tourism sector, the paper aims to promote open debate and discussion among relevant actors and stakeholders in the space tourism sector.

It provides an overview of the space tourism sector, proposes a definition of “uncontrolled human conception in emerging space tourism,” and lists the relevant community in the form of actors and stakeholders.

The scope of the paper focuses on the short to medium-term space tourism expected within approximately the next ten years.

The authors categorize space tourism into three sub-sectors:

  • Terrestrial space tourism, which includes tours of ground-based space facilities, dark skies astronomy, and other ground-based activities.
  • Atmospheric space tourism and which includes weightless parabolic aircraft flights and
    stratospheric balloon capsules.
  • Astro-tourism includes suborbital flights beyond the Kármán line, Earth-orbital flights, and
    beyond Earth-orbit flights

The focus is solely on Astro-tourism, which exposes participants to space environments of interest for appropriate durations.


The aspects of space tourism that are the focus of the current paper are those that expose human participants to space environments for time durations that could be expected to affect the early stages of human reproduction.

The paper suggests that early stages of human reproduction could occur in the very near future during spaceflight and while exposed to space environments.

The authors hope to use this green paper to gather further community inputs to produce a white paper version and then further disseminated via publication in a peer-reviewed journal.

Effects of Microgravity on the Human Body

The effects of microgravity on the human body have been a major focus of space exploration since the early days of manned spaceflight.

As humans are designed to live and operate under the influence of Earth’s gravity, adapting to the unique environment of space can be a challenge for the body.

Microgravity can affect many physiological systems, including the cardiovascular, musculoskeletal, and immune systems, as well as the sensory organs, like bone and muscle loss is one of the main effects of microgravity.

In microgravity, the body no longer has to fight against gravity to support itself, causing bones and muscles to weaken over time.

Astronauts have been known to lose up to 20% of their bone mass during long-duration space missions, however, they regain most of their bone mass in the months following their return from space, but not all of it.2.

In the early stages of space tourism, where exposure to space environments is limited to days or weeks, the reproductive processes of interest are gametogenesis, fertilization, embryogenesis, and implantation.

Male gametogenesis or spermatogenesis is a complex process that takes around 74 days, and testicular tissue is highly sensitive to radiation, making germline consequences from microgravity and radiation exposures possible.

Females have a finite number of gametes, and the pool of primordial follicles and primary oocytes remain in an arrested state until puberty.

Concerning female gametogenesis and spaceflight, there are examples of female astronauts becoming pregnant post-spaceflight and delivering babies without any identified space-specific concerns.

However, females who conceive shortly after returning from spaceflight may be exposed to the unknown risks of space environments.


The immune system is also affected by microgravity, studies have shown that exposure to microgravity can suppress the immune system, making Astronauts more susceptible to infection.

And lack of natural microbial exposure in space can also affect the immune system, as the body is not exposed to the same range of microbes as on Earth.

In 2018, NASA’s “Spaceflight-Altered Motility Activation and Fertility-Dependent Responses in Sperm” (Micro-11) investigation on the ISS studied the effects of microgravity on human sperm motility and capacitation for fertilization, but the results of this study are not yet available to the public.

While these effects can be managed and mitigated to some extent, they remain a significant challenge for human spaceflight.

Implications for Space Tourism

According to the paper, the sociological context plays a significant role in determining the potential for uncontrolled human conception in space tourism.

However, limited research has been published on sexual relations in space, with most studies focusing on past and current astronauts and a long-term future of human exploration and living beyond Earth.

Professional Astronauts are less likely to engage in sexual activity in space due to the selection processes, career pathways, professional culture, and peer expectations that emphasize mission-oriented goals and minimize behavior deemed inappropriate.

But as the nature of space tourism evolves, the motivation, behavior, culture, and peer expectations of space tourists will also change.

Space tourists are more likely to have a greater range and individual diversity of motivations and behavior, attracting behavioral types such as risk-takers and novelty-seekers, posing a risk associated with a willingness to disregard rules, regulations, and societal norms.

The risks and consequences of uncontrolled human conception in emerging space tourism have not been discussed by the relevant community of actors and stakeholders in a public forum.

NASA’s culture, which avoids public discussion of human sexuality, has contributed to the broader spaceflight landscape and space tourism sector, especially those elements coming from an engineering and governmental background.

Authors represent a predominantly Western cultural perspective, and it is essential to ensure that voices representing all cultural backgrounds are considered.

As part of any community considerations, all possible situations relating to uncontrolled human conception should be included, including the possibility of, and consequences of, non-consensual as well as consensual human conception.

The need to address the potential for sexual harassment and assault in space-related contexts has also been highlighted.

While the research on the effects of microgravity on human reproduction is still inconclusive, the rising interest in space tourism means that this is a topic that requires further consideration.

As the space industry continues to grow, it is important to discuss the potential impact of sex in space on the human body, the mental and emotional well-being of astronauts, and the ethical implications of such activities.

Only then can we develop comprehensive policies and protocols to ensure the safety and well-being of those who venture beyond our planet.



  1. David C. Cullen*, Matthew C. Hudnall et al., ‘Sex in Space: Consideration of uncontrolled human conception in emerging space tourism‘, Zenodo, 21 April 2023[]
  2. NASA, ‘Bones in Space‘,[]