Skip to main content

Healthy ‘space pup’ mice born from sperm stored on International Space Station

Healthy 'space pups' born from sperm which had been freeze-dried on the International Space Station.
These healthy “space pup” mice were born from sperm that had been freeze-dried and stored on the International Space Station. Teruhiko Wakayama/University of Yamanashi

Healthy mice — charmingly referred to as “space pups” — have been born from sperm that was freeze-dried before spending nearly six years on the International Space Station (ISS).

Questions remain about fertility in space, so the research on the frozen mouse sperm is important. It’s not clear whether humans can get pregnant in space, or if traveling to space while pregnant would harm a fetus. Since long-term plans call for humans to occupy bases far from Earth, fertility is a major concern.

There are two prominent problems with fertility in space: Microgravity causes sperm to behave strangely, and radiation present in space is potentially harmful. On Earth, we are protected from radiation from space by the planet’s magnetosphere, but as humans travel farther from Earth, the amount of radiation increases.

The mouse sperm experiment looked at the radiation hazard in particular. Researchers took the sperm from mice and sealed it in vials, which were then freeze-dried. Some of the material was sent to the ISS, while more stayed on Earth. The samples spent up to five years and 10 months on the ISS and were returned to Earth for testing.

The good news for those hoping for space colonies one day is that the sperm was able to be used to impregnate mice on Earth, and the pups born from the space sperm were healthy. Even the children of these pups were healthy, too. “These space pups did not show any differences compared to the ground-control pups, and their next generation also had no abnormalities,” the researchers wrote in a research paper.

In their paper, the researchers write that frozen cells intended for reproduction likely will head to space in the future, given the need to transport not only humans but also pets and domestic animals. Keeping a population healthy requires genetic diversity, so freezing and packing sperm and/or eggs would help to ensure enough genetic variety to sustain populations away from Earth.

The authors even speculate that freezing genetic material could be important for the preservation of life in the event of environmental destruction on Earth. Natural disasters also could threaten humans and other populations, and the researchers suggest that sending freeze-dried genetic material into space could be a way to preserve species for the future.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Amazing Earth photos shared by outgoing ISS astronaut
Earth as seen from the International Space Station.

Andreas Mogensen became the first Dane in orbit when he arrived at the International Space Station (ISS) as part of SpaceX’s Crew-7 in August 2023.

After just over six months aboard the orbital outpost, the astronaut is now preparing to head back to Earth with his three colleagues aboard a SpaceX Crew Dragon spacecraft.

Read more
How to watch Crew-8 arrive at the space station tonight
A SpaceX Crew Dragon carrying the Ax-3 crew departs from the space station in February 2024.

NASA Live: Official Stream of NASA TV

SpaceX’s Crew-8 members are about to arrive at the International Space Station after launching from the Kennedy Space Center on Monday.

Read more
Air is leaking from Russian module of the International Space Station
The International Space Station.

The International Space Station (ISS) is experiencing a leak from a Russian module, but NASA assures the public that it is no threat to the crew on board. While it is not usual for a small amount of air to leak from the ISS regularly, this leak has recently increased in volume, which is why it has been closely observed.

At a briefing regarding the upcoming launch of Crew-8 to the station, now rescheduled for late Saturday night, Joel Montalbano, manager of the International Space Station Program, spoke about the leak. Montalbano said the leak had been observed since before the launch of the Russian Progress resupply craft in February, when it was leaking at a rate of around 1 pound per day. But since the arrival of the Progress craft, it has increased to around 2 pounds per day.

Read more