Eight-legged water bear to travel to space: Here's why Shubhanshu Shukla is taking a tardigrade on a space mission

Eight-Legged Water Bear to Travel to Space: Here's Why Shubhanshu Shukla Is Taking a Tardigrade on a Space Mission

As Indian astronaut Shubhanshu Shukla prepares for his upcoming two-week journey aboard the International Space Station (ISS) as part of the Axiom-4 mission, he’s not going alone. Along with his scientific gear, he’ll carry one of the smallest yet most durable lifeforms on Earth—a tardigrade. This microscopic “water bear” is central to the Voyager Tardigrades mission, an experiment aimed at unravelling how life can thrive in space’s harsh conditions.

Meet the Tardigrade: Nature’s Tiny Survivor

Tardigrades, affectionately known as “water bears” or “moss piglets”, are microscopic creatures just 0.5 millimetres long. Despite their size, they are among Earth’s toughest organisms. These eight-legged animals have survived all five mass extinction events and can live in extreme places—from ocean trenches to mountaintops. Most are found in mosses and lichens, feeding on plant cells, algae, and tiny invertebrates.

Their superpower lies in a process called cryptobiosis, which allows them to shut down almost all biological functions when faced with environmental stress. In their tun state—a dry, shrivelled form—they can lose over 95% of their body water and still recover. Inside this state, they produce special proteins called CAHS, which form a glass-like gel to protect DNA and vital cell parts.

Why Tardigrades Are Going to Space

The Voyager Tardigrades mission will see these creatures launched into space in their dormant tun state. Once on the ISS, scientists will rehydrate them and observe how microgravity and radiation affect their biology. The goal is to identify the genes and molecular tricks that allow tardigrades to repair DNA, withstand radiation, and function in space.

These insights could change the future of human space exploration. If scientists can harness tardigrade biology, they could better protect astronauts from radiation, combat muscle and bone loss in zero gravity, and improve long-term preservation of biological material in space.

A History of Survival Beyond Earth

This won’t be the tardigrades’ first spaceflight. In 2007, about 3,000 were sent on the European Space Agency’s Foton-M3 mission. Some were exposed directly to space. Despite the brutal conditions, many returned alive—and even managed to reproduce—making them the first animals known to survive outer space without a suit or a spacecraft.

Now, with India stepping into advanced space biology, Shukla’s mission marks another step forward. By studying these creatures, Indian scientists could contribute to a future where human life thrives beyond Earth—and where tiny water bears help guide the way.