As Earth grapples with global crises like pandemics, extreme weather, and escalating natural disasters, proponents of space colonization stress the need for humanity to look beyond our planet. Outposts on the moon or Mars could serve as an “insurance policy” for survival in the face of catastrophe. However, one fundamental question remains: Can humans reproduce in space?
To answer this, freeze-dried mouse sperm stored aboard the International Space Station (ISS) could pave the way. Spearheaded by Teruhiko Wakayama, a professor at Japan’s University of Yamanashi Advanced Biotechnology Centre, the experiment aims to explore whether mammalian reproduction is possible in the harsh environment of space.
The samples, protected from radiation in a specialized device, will return to Earth in 2025 for analysis. Wakayama’s team will study the impact of space on sperm DNA and assess its viability for creating healthy offspring. The research could revolutionize our understanding of reproduction beyond Earth and determine if sustaining life on other planets is achievable.
From Mice to Mars: Understanding Reproduction in Space
Wakayama’s groundbreaking work isn’t new. In a prior study, his team sent freeze-dried mouse sperm to the ISS, where it was stored for up to six years. Upon returning to Earth, the rehydrated samples successfully produced healthy baby mice. The experiment revealed that freeze-dried sperm could remain viable in space for 200 years—a significant breakthrough but, as Wakayama insists, “absolutely not long enough for our future.”
His latest initiative involves developing a new radiation-protection device that allows sperm storage at room temperature indefinitely, a critical step toward preserving Earth’s genetic resources in space. This, Wakayama believes, could one day enable life to flourish on extraterrestrial colonies, even if Earth faces total destruction.
The experiments also include creating an in vitro fertilization (IVF) system aboard the ISS. Wakayama envisions astronauts conducting IVF with rodent sperm in microgravity within the next few years—a critical precursor to testing the full mammalian reproductive cycle in space.
The History of Space Reproduction Experiments
Space biology has long been a topic of intrigue. Over the decades, scientists have launched a variety of species into orbit to observe how cosmic radiation and microgravity affect reproduction:
- 1989: The “Chix in Space” experiment sent fertilized chicken eggs into orbit, sponsored by KFC, to study embryonic development without gravity.
- 1992: Tadpoles aboard the Space Shuttle Endeavour struggled to swim in microgravity and locate air bubbles. Female frogs aboard the same mission shed eggs fertilized in space.
- 2007: A cockroach named Nadezhda gave birth to 33 offspring conceived in orbit, though they exhibited unusually dark exoskeletons.
While fish like medaka and small invertebrates such as snails have completed full reproductive cycles in space, mammals present a new and complex challenge. “Going to mammals is the next natural step,” says Virginia Wotring, professor at the International Space University in France.
Why This Research Matters
Humans are inching closer to becoming a multi-planet species. NASA’s Artemis program will return astronauts to the moon in 2026, while SpaceX’s Elon Musk predicts a crewed mission to Mars within the next four years. However, space travel takes a heavy toll on the human body.
- Cosmic radiation can damage DNA, increasing the risk of cancer and other health problems.
- Microgravity causes muscle loss, weakened immunity, and impaired vision.
If reproduction in space proves difficult, damaged sperm and eggs could lead to genetic abnormalities in future generations. Moreover, without Earth’s gravitational pull, embryonic development might be disrupted, raising concerns about the proper formation of limbs, organs, and nervous systems.
Wakayama’s research could address these uncertainties. His experiments focus on ensuring the viability of reproductive cells and understanding how embryos develop in microgravity—key steps toward sustaining human life on lunar or Martian bases.
A Vision for the Future
While Wakayama remains focused on mice for now, his work lays the foundation for transporting other species—like livestock for food or dogs for companionship—to space. His IVF project, currently under development, has been accepted by Japan’s space agency and could launch to the ISS within two years.
“In sci-fi movies, people live on other planets and babies are born, but we don’t even know if that’s possible yet,” Wakayama states. His goal is to bring clarity to this question and offer reassurance about humanity’s ability to reproduce and thrive off Earth.
If successful, the implications are enormous. Humanity could preserve genetic material indefinitely in space, ensuring survival even in the face of catastrophic Earth-bound events. Wakayama believes this vision is essential for securing the future of life as we know it.
Conclusion: Preparing for a Multi-Planet Future
Mouse sperm orbiting Earth may seem like a small step, but it represents a giant leap toward understanding the potential for life beyond our planet. As humans set their sights on the moon, Mars, and beyond, Wakayama’s pioneering research could hold the key to humanity’s survival and growth in the final frontier.
In his own words, “If it doesn’t work, we need to understand how to address that challenge.” The future of humanity might just depend on it.
