Studying fertility in space can be difficult. At the moment, astronauts do not spend several years in a microgravity environment. But someday our descendants will travel to other planets – and, eventually, perhaps even deeper into the cosmos. Building a long-term space colony will require researchers to have a better understanding of the impact of microgravity on mammalian reproduction, as well as how DNA mutations due to increased radiation exposure might. be transmitted to the offspring.
That’s where mouse sperm comes in. For nearly six years, researchers kept a batch of freeze-dried mouse sperm aboard the International Space Station (ISS) to study how radiation and microgravity affect this key element of reproduction.
In one study published on June 11 in Scientists progress, a team of researchers examined how three different batches of mouse semen freeze-dried on the ISS have held up over time. The first set was stored for just nine months to make sure the experiment was working, while the second and third sets were in space for almost three and six years, respectively. The researchers found that despite years stored in space, once resuscitated, mouse sperm could still perform its primary task, resulting in the birth of a number of healthy, normal puppies.
In an additional experiment, additional X-radiation was applied to a few frozen and control test semen samples. Based on the results, the team predicts that sperm could potentially remain viable for more than 200 years on the ISS.
However, there is one caveat under consideration that should be noted: The ISS orbits Earth about 250 miles (400 kilometers), well within our planet’s protective magnetic field. This means that the sperm underwent less space radiation than it would encounter on a trip to, say, Mars. However, when NASA and its partners finish building Lunar Gateway, the proposed lunar space station, the team hopes to continue researching mammalian fertility in space.
Although this is only a mouse trial, it is a big step forward in studying the complex world of fertility in space.