Samantha Cristoforetti / Flickr
Parabolic flight
The experiment aimed to discover the effects of microgravity on human sperm. The results are not promising.
With climate change affecting the planet’s habitability, the focus on space exploration, the possibility of humans form colonies beyond Earth seems closer than ever.
This change could raise important questions about human reproduction in space, an area that remains largely unexplored, particularly in microgravity conditions. A recent published in the magazine Astronautical thread addressed this topic, exploring how microgravity affects human sperm.
The study states that while interest in long-duration space travel and tourism grows, research into the impact of microgravity in human reproduction has lagged behind due to technical and ethical restrictions.
Data collection is challenging: it is not feasible to collect sperm samples directly on the International Space Station (ISS) nor is it appropriate to involve astronauts in these studies. In a creative solution, the research team behind the study used parabolic flights, also known as “vomit comets””, to imitate microgravity for short periods.
Although parabolic flights introduce brief windows of weightlessness, they are followed by periods of “hypergravity” as the aircraft rises and falls. While these conditions are not ideal for a long-term microgravity simulation, they offer an economical and accessible method for preliminary investigation, writes the .
The team collected and analyzed sperm samples from 15 volunteers before the flight and divided them into two groups: one remained on the ground as a control, while the other experienced microgravity in flight. Airborne samples were securely attached to seats and monitored with sensitive accelerometers to ensure they were exposed to minimal interference during maneuvers.
After returning the samples to the laboratory for post-flight analysis, researchers observed a significant decrease in motility and the vitality of sperm exposed to microgravity. This decline could indicate potential problems for human reproduction in space, particularly on long-term space missions or in future colonies.
The team noted that the exact mechanism causing reduced motility remains unknown and suggests further studies to understand the effects of prolonged exposure to microgravity.
