These “animal astronauts” performed numerous missions in space, and one notable success came from a NASA mission that involved sending 2,487 jellyfish into space for reproduction.
As part of NASA’s Spacelab Life Sciences-1 (SLS-1) mission launched in 1991, the jellyfish were packed in seawater-filled bags and launched into space aboard the space shuttle Columbia.
Surprisingly, after orbiting the Earth for over a month, the 2,487 jellyfish reproduced and gave birth to more than 60,000 offspring. It seemed that in space, the reproductive capabilities of jellyfish were greatly enhanced.
The scientists involved in the project were filled with newfound hope and began preparing to use similar methods to test the reproductive abilities of other aquatic species in space. Furthermore, they envisioned the possibility of humans reproducing in space, transforming the universe into a long-term habitable place.
Unusual Discovery
However, before these aspirations could be realized, the scientists discovered something peculiar.
All the jellyfish born in space exhibited a strange behavior when brought back to Earth. They swam with their heads downward, moving unsteadily as if intoxicated.
These jellyfish lost their ability to orient themselves and moved much more clumsily compared to their counterparts born on Earth. In other words, space jellyfish were entirely unfamiliar with the magnetic field of this planet.
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Space jellyfish are “blind” to Earth’s magnetic field. (Image: The Conversation)
Inside a typical jellyfish, there are numerous gravity-sensing receptors in the form of calcium sulfate crystals held within sensitive hair cells. When a jellyfish changes its direction of movement, the calcium sulfate crystals sink to the bottom of the cells, signaling which direction the hair cells should follow.
The researchers noted that the gravity-sensing receptors in the space jellyfish appeared normal but failed to function properly. These receptors might have been incorrectly calibrated or improperly connected to the jellyfish’s nervous system.
Humans also have a fluid in their inner ear that operates similarly to the gravity-sensing receptors in jellyfish. Consequently, it is highly likely that humans nurtured in a microgravity environment would struggle to move normally upon returning to Earth.
Similar phenomena have been observed in the reproduction of other animal species in space. According to NASA, fish and tadpoles swim in a circular path instead of a straight line when taken into space.
In 2007, Jeffrey Alberts worked with NASA to study how the final week of pregnancy in mice in space would affect their newborns. Alberts discovered that the newborn mice born outside of Earth’s gravity were unable to flip themselves over and remained on their backs, even when submerged in water. However, this condition did not persist indefinitely, and their normal sense of gravity gradually returned over time.
A study published in PLoS ONE in 2011 revealed that snails living in space are highly sensitive to gravity. When tilted or turned upside down, they attempt to rotate faster than snails born on Earth, but they do not always rotate in the correct direction.
Further research is required before conclusive findings can be drawn regarding how growing up in space affects humans. However, it is evident that growing up in a microgravity environment would result in some truly “peculiar” experiences.