In the late 1940s, humans began conducting experiments by sending various animal species into space to study the effects of microgravity on living organisms.
These “animal astronauts” have repeatedly undertaken various missions in space. Among them, one NASA mission achieved remarkable success: 2,487 jellyfish were bred in space.
As part of NASA’s first Spacelab Life Sciences mission (SLS-1), which launched in 1991, the 2,487 jellyfish were packed in bags of seawater and launched into space aboard the Space Shuttle Columbia.
The results were astonishing; after more than two weeks orbiting Earth, the 2,487 jellyfish had reproduced to over 60,000 individuals. It seemed that in space, the reproductive capabilities of jellyfish were significantly enhanced.
At that time, scientists were filled with new hope and prepared to use similar methods to test the reproductive capabilities of other seafood species in space. Furthermore, they aspired for humans to reproduce in space, potentially making the cosmos a long-term habitat.
Discovering the Anomaly
However, before they could realize this ambition, scientists involved in the project noticed something unusual.
All the jellyfish born in space became “disoriented” when returned to Earth; they swam with their heads down and moved unsteadily like drunken beings.
These jellyfish lost their ability to orient themselves, finding it much more challenging to move compared to their Earth-born relatives. In other words, the space jellyfish were completely unfamiliar with the magnetic field on this planet.
Space jellyfish were “blind” to the Earth’s magnetic field. (Photo: The Conversation).
Inside a normal jellyfish, there are many gravity-detecting receptors (graviceptors) in the form of calcium sulfate crystals, held within sensitive hair cell sacs. When a jellyfish changes direction, the calcium sulfate crystals sink to the bottom of the sacs and signal the hair cells which direction to follow.
Researchers noticed that the gravity-detecting receptors of the space jellyfish appeared normal but were not functioning. It is possible that these receptors were miscalibrated or improperly connected to the jellyfish’s nervous system.
Humans also possess a fluid in the inner ear that operates similarly to the gravity-detecting receptors of jellyfish. Therefore, it is highly likely that individuals raised in a microgravity environment would struggle to move normally upon returning to Earth.
Many other animal species bred in space have also shown similar phenomena. According to NASA, fish and tadpoles swim in circles instead of straight lines when brought into space.
In 2007, Jeffrey Alberts collaborated with NASA to investigate how a mother mouse’s final week of pregnancy in space might affect her newborns.
Alberts discovered that the mice born in space could not flip themselves over; they lay on their backs even while submerged in water. However, this condition did not persist indefinitely, as their normal sense of gravity gradually returned over time.
A study published in PLoS ONE in 2011 showed that snails living in space were very sensitive to gravity. When tilted or upside down, they attempted to right themselves faster than Earth-born snails, but they did not always turn in the correct direction.
Scientists will need to conduct further research before concluding how growing up in space affects humans. However, it is easy to recognize that growing up in a microgravity environment would undoubtedly be quite “peculiar.”
