With pandemics, climate crises, and natural disasters threatening life on Earth, the quest to find a safe haven beyond our planet is becoming increasingly urgent. Proponents of human settlements on the moon or Mars envision them as an “insurance policy” against extinction. However, one fundamental question remains: Can humans reproduce in space?
Scientists, led by Teruhiko Wakayama of Japan’s University of Yamanashi, are tackling this challenge through groundbreaking research involving freeze-dried mouse sperm stored aboard the International Space Station (ISS). The findings could determine if mammals—humans included—can procreate and sustain life in space, bringing us closer to a multi-planetary future.
The ISS and the Mouse Sperm Experiment
On the ISS, Wakayama’s team placed freeze-dried mouse sperm in a specialized radiation-protection box. Unlike previous experiments that studied amphibians, fish, and insects, this is a crucial step toward understanding mammalian reproduction beyond Earth. The sperm will return to Earth in 2025, where researchers will analyze its viability and potential to produce healthy offspring.
Wakayama’s mission goes beyond short-term experiments. Previous studies revealed that freeze-dried sperm could remain viable for up to 200 years in space. However, Wakayama insists that is still “not long enough for our future.” His latest experiment introduces a new device to store reproductive cells indefinitely at room temperature while shielding them from cosmic radiation.
From Sci-Fi to Reality: The Long History of Space Reproduction
The concept of space reproduction has long fascinated scientists and science-fiction enthusiasts alike. For decades, researchers have launched Earth’s creatures into orbit to observe biological processes in microgravity.
- “Chix in Space” (1989): Sponsored by KFC, fertilized chicken eggs were sent into space, though development faced challenges in microgravity.
- Tadpoles on Endeavour (1992): Frog embryos hatched aboard the Space Shuttle Endeavour struggled to swim properly and locate air bubbles.
- Cosmic Cockroaches (2007): A cockroach named Nadezhda gave birth to 33 offspring in orbit, which displayed slightly abnormal exoskeletons.
These experiments confirmed that some species could complete phases of the reproductive cycle in space, but mammals remain largely untested.
Why It Matters: Humanity’s Survival in Space
As NASA’s Artemis program prepares to return astronauts to the moon by 2026 and private ventures like SpaceX eye Mars missions within the next decade, sustaining life in space becomes a critical concern.
While reproduction may not be a top priority for current missions, Teruhiko Wakayama believes his work is vital for long-term space habitation. Damaged DNA caused by cosmic radiation could introduce genetic abnormalities into sperm and eggs, potentially impacting the health of future generations. Additionally, microgravity raises concerns about embryo development, including the formation of limbs and the nervous system.
“We don’t know if fertilized embryos will develop properly in microgravity, where there is no up or down,” Wakayama explains.
Future Prospects: Reproduction for Humans and Animals
Wakayama’s research isn’t just about humans—it could enable the preservation and transportation of other species essential for life on other planets. Companion animals like dogs and livestock such as cattle could be transported to provide emotional support and sustainable food sources.
While Wakayama’s immediate focus is on mice, his team is developing a device that will allow astronauts to perform rodent in vitro fertilization (IVF) aboard the ISS. The project, accepted by Japan’s space agency, is expected to launch within two years.
The Next Frontier: Proving Reproduction in Space
“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 says. His experiments could finally answer this question.
If the research confirms mammals can reproduce and develop normally in space, it would provide reassurance that life can be sustained off Earth. If not, scientists will face the next big challenge: overcoming biological limitations to ensure humanity’s survival.
Conclusion: A Cosmic Insurance Policy for Humanity
The ability to reproduce in space is crucial to humanity’s long-term survival as we venture beyond Earth. Experiments like Wakayama’s freeze-dried mouse sperm aboard the ISS are pioneering steps toward securing life on other planets. As we prepare to become a multi-planetary species, understanding and mastering space reproduction could be the key to ensuring a thriving future—wherever humanity calls home.
