Earth has faced unprecedented challenges in recent years, from a global pandemic to extreme weather events and natural disasters, CNN reports.
These crises underscore the need for humanity to consider alternatives to life on Earth, including potential colonies on the moon or Mars. Advocates of this idea argue that extraterrestrial outposts could provide a safety net against extinction. However, one critical question remains: Can humans reproduce in space?
A new study involving freeze-dried mouse sperm stored aboard the International Space Station (ISS) aims to explore this possibility. The findings could help determine whether mammals, including humans, can procreate beyond Earth, offering insights into the viability of establishing permanent settlements in space.
Led by Professor Teruhiko Wakayama from the University of Yamanashi’s Advanced Biotechnology Centre in Japan, this experiment is testing how space radiation affects reproductive cells. The freeze-dried sperm samples were stored on the ISS in a protective container and are set to return to Earth in 2025 for analysis.
Back on Earth, Wakayama plans to examine whether the samples can produce healthy offspring, shedding light on the long-term effects of space environments on mammalian reproduction. This builds on previous experiments where mouse sperm stored on the ISS for six years was successfully rehydrated and used to create viable offspring.
Wakayama’s research is also focused on developing a device that would enable astronauts to perform rodent in vitro fertilization (IVF) aboard the ISS. The ultimate goal? To establish a system for preserving Earth’s genetic material in space permanently, potentially serving as a safeguard for life on Earth in the face of catastrophic events.
Understanding reproduction in space is critical for long-term human survival off Earth. While experiments involving fish, amphibians, and invertebrates have demonstrated varying degrees of reproductive success in microgravity, mammals present more complex challenges.
- Radiation Risks: Cosmic radiation can damage DNA in sperm and eggs, potentially leading to genetic mutations passed to the next generation.
- Microgravity Effects: The lack of gravity may interfere with embryonic development, raising concerns about the proper formation of organs and limbs in an environment where “up” and “down” don’t exist.
Wakayama believes his research could pave the way for transporting other species, such as livestock for food and pets for companionship, to other planets. However, for now, his focus remains on mice, with plans to launch an ISS-compatible IVF device within the next two years.
For decades, scientists have studied how living organisms reproduce in space. Notable experiments include:
- Chix in Space (1989): Fertilized chicken eggs were sent into orbit to observe their development in microgravity.
- Space Tadpoles (1992): Tadpoles born aboard the Space Shuttle Endeavour swam erratically and struggled to locate air bubbles, offering insights into microgravity’s impact on motor control.
- Cosmic Cockroaches (2007): A cockroach named Nadezhda gave birth to 33 offspring conceived in orbit. While most were healthy, they exhibited unusually dark exoskeletons, suggesting potential developmental changes due to space exposure.
Medaka fish and snails have completed full reproductive cycles in space, but experiments involving mammals are still in the early stages.
As humans inch closer to becoming a multi-planetary species, initiatives like NASA’s Artemis program aim to establish a sustainable presence on the moon, while private companies like SpaceX are eyeing Mars for human settlement. However, the physiological effects of space travel—ranging from DNA damage caused by radiation to weakened muscles and bones in microgravity—remain significant hurdles.
Virginia Wotring, a professor at the International Space University in France, emphasizes that astronaut health must take precedence over reproduction research for now.
“We need more immediate information to care for the astronauts we’re sending into space today,” she says.
Wakayama, however, argues that reproduction research is vital for the long term. Without it, humanity risks encountering insurmountable challenges in creating sustainable space colonies.
“If we can confirm that reproduction is possible, it will bring reassurance,” he says. “And if it doesn’t work, we need to understand how to address that challenge.”
