The Indian Space Research Organisation (ISRO) intends to send tardigrades, often referred to as water bears, to the International Space Station

Overview of the Axiom-4 Mission and Tardigrades: The Axiom-4 Mission is a 14-day crewed expedition to the International Space Station (ISS) as part of the Axiom Space initiative, focusing on research in microgravity biology, biotechnology, and sustainability.

This mission is a collaborative effort involving ISRO (India), NASA (USA), and ESA (Europe), with Indian astronaut Group Captain Shubhanshu Shukla participating. The mission aims to investigate life sciences, space agriculture, and human physiological responses, evaluate microbial resilience, muscle regeneration, and food cultivation in a zero-gravity environment, and contribute to India's Gaganyaan Mission and future long-duration spaceflights.

Tardigrades, also known as water bears or moss piglets, are micro-animals measuring between 0.3 to 0.5 mm, only visible under a microscope, and were first identified in 1773 by German zoologist Johann Goeze. These creatures are characterized by their presence in extreme environments, possessing eight legs with claws, segmented bodies, and a resilient outer skin.

They can endure extreme conditions such as the vacuum of space, radiation, dehydration, and extreme temperatures by entering a state of cryptobiosis, or suspended animation. The Voyager Tardigrades Experiment aims to investigate their revival and reproduction in microgravity and the differences in gene expression between those exposed to space and those on Earth.

This research is significant as it may reveal molecular mechanisms of resilience, inform biotechnological advancements and astronaut protection strategies, and enhance bio-preservation methods for extended missions.