Why NASA Sent Thousands Of Jellyfish To Space In The Early 1990s

You've heard of monkeys traveling to space, but, uh, jellyfish?

Back in the 1990s, when we had space shuttles available to ferry things into orbit, we sent jellyfish into space. It seemed almost comically simple to come up with a science experiment. Choose an object or a living thing, launch it into orbit, see what happens. But it wasn't as easy as it seemed to be.

Since the early 1990s, NASA has sent thousands of jellyfish into Earth's orbit, apparently to test the effects of the microgravity environment on creature development and to see how they would adjust when they returned to Earth.

Around 2,500 jellyfish polyps were launched into space by the space shuttle Columbia in 1991, all contained in bags filled with artificial seawater. According to The Atlantic reports, the jellies multiplied in space, and by the end of the mission, as many as 60,000 jellyfish were orbiting Earth.

Researchers chose jellyfish for the experiment because, like the super-sensitive hair cells in human ears that help us detect gravity, jellyfish have special cell hairs around their bell that allow them to feel the way they're going.

Humans have similar structures to sense. We feel both gravity and acceleration by using otoliths, calcium crystals in our inner ears that move ultra-sensitive hair cells, informing our brains how gravity is pulling us. So if the space-raised jellyfish did not fully develop their version of the gravity-sensors, the thinking goes. Humans raised in microgravity would likely have similar problems.

The experimental results, Not to be encouraging. Researchers found that jellies raised in space had an impaired sense of gravity compared to their earthly relatives, even though they were "morphologically very similar" to those on Earth.

When they returned to Earth, "they lacked the proper gravity-sensing abilities and had difficulty figuring out how to swim around in normal gravity, resulting in abnormal pulsing and movement."

These results suggest that if we humans are to spend generations traveling to another system, we will have to figure out how human children can be raised in space. Otherwise, our colonization efforts may have stumbled before they even set foot on the planet.