The challenges facing humanity on Earth, from pandemics to catastrophic climate events, have driven some to imagine a future beyond our planet. The idea of establishing outposts on the Moon or Mars as an “insurance policy” against extinction has gained traction. However, a significant unknown remains: can humans reproduce in space?
An experiment involving freeze-dried mouse sperm aboard the International Space Station (ISS) could provide groundbreaking insights into mammalian reproduction in space and humanity’s potential to colonize other planets.
The Experiment: Mouse Sperm in Orbit
In a bid to understand the effects of space on reproduction, freeze-dried mouse sperm has been stored aboard the ISS in a radiation-protected container. Led by Professor Teruhiko Wakayama of the University of Yamanashi’s Advanced Biotechnology Centre in Japan, the study aims to assess the viability of reproductive cells exposed to cosmic radiation and microgravity.
When the sperm samples return to Earth in 2025, Wakayama’s team will study whether they remain viable for fertilization and can produce healthy offspring. Building on previous successes, including the production of baby mice from sperm stored in space for six years, this experiment could pave the way for creating a permanent system to preserve Earth’s genetic resources beyond our planet.
“Our goal is to preserve [reproductive cells] at room temperature forever,” Wakayama says. This would be a major leap in ensuring the survival of life even if Earth faces catastrophic destruction.
The Journey to Space Reproduction
Space experiments on reproduction are not new. Over the decades, various creatures have been sent into orbit to study the impact of microgravity and cosmic radiation on biological processes:
- “Chix in Space” (1989): Fertilized chicken eggs were sent into orbit, though the experiment yielded mixed results.
- Frogs and Tadpoles (1992): Tadpoles born aboard the Space Shuttle Endeavour swam erratically in microgravity and struggled to find air bubbles.
- Cockroaches (2007): A cockroach named Nadezhda gave birth to 33 offspring in orbit, with some minor differences in their physical characteristics.
These experiments demonstrated that some phases of the reproductive cycle can occur in space, though not always successfully. However, transitioning from smaller organisms to mammals presents new challenges, particularly regarding the complex development of embryos and the role of gravity in organ formation.
Implications for Space Exploration
As space programs like NASA’s Artemis aim to establish a human presence on the Moon by 2026, and Elon Musk’s SpaceX eyes Mars missions within the next few years, understanding reproduction in space becomes critical for long-term survival.
Scientists already know that space travel impacts the human body significantly. Cosmic radiation increases DNA mutations, leading to higher cancer risks, while microgravity weakens muscles and bones. These factors raise concerns about the viability of reproduction in space, as damaged DNA in sperm and eggs could pass genetic abnormalities to the next generation.
“The formation of the nervous system and the development of limbs … we don’t know if this will happen properly in microgravity,” Wakayama notes. Understanding these processes will be crucial for ensuring normal development in space-borne offspring.
Beyond Humanity: Preserving Earth’s Genetic Legacy
Wakayama’s vision extends beyond humans. His work could serve as a model for preserving genetic material from other species, enabling the transport of animals like livestock for food and pets for companionship to other planets.
Using his pioneering freeze-drying method, Wakayama has demonstrated that mouse sperm can remain viable in space for up to 200 years. However, he acknowledges that this is insufficient for long-term survival. His current research involves developing a device to shield sperm from radiation, allowing for indefinite preservation in space.
Reproduction: The Final Frontier
While humans are still far from becoming a multi-planet species, Wakayama’s experiments represent a critical step in overcoming the reproductive barriers posed by space. His team is developing an in vitro fertilization (IVF) device that could allow astronauts to fertilize rodent embryos aboard 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 explains.
His research aims to answer fundamental questions: can humans and other mammals reproduce in space? If not, what steps can be taken to overcome these challenges?
A Glimpse into Humanity’s Future
The success of Wakayama’s experiments could provide humanity with a lifeline for survival beyond Earth. If reproduction in space proves feasible, it would ensure the continuity of life on other planets. If not, understanding the limitations will guide future innovations to address these challenges.
“Our aim is to establish a system for safely and permanently preserving Earth’s genetic resources somewhere in space,” Wakayama says. “So that life can be revived even if Earth faces catastrophic destruction.”
As humanity inches closer to becoming a multi-planet species, experiments like these could determine whether the sci-fi dream of thriving colonies on other worlds becomes a reality.
This experiment is not just about mice; it’s about the survival of life itself—ushering in a new era of possibilities where Earth’s legacy is preserved among the stars.
