Context: The Axiom Mission 4 will see India, Poland, and Hungary’s first government-sponsored human spaceflight in more than 40 years next month.

Meaning of the context: Among the studies set to be carried out in the mission is ISRO’s Voyager Tardigrades project, which will investigate the revival, survival, and reproduction of tardigrades – creatures that have long fascinated scientists.

Learning Zone:

Water Bears Or Tardigrades

• Tardigrades are microscopic, eight-legged animals measuring 0.1 to 0.5 millimetres, found across terrestrial, marine, and freshwater environments worldwide, and are renowned for surviving extreme conditions—from arid deserts to the heights of the Himalayas.
• They can also go without food or water for up to years, although their average lifespan is not more than a decade.
• Remarkable resilience has enabled tardigrades to survive on Earth for approximately 600 million years and makes them likely to endure significant climatic changes in the foreseeable future.
• Survival Mechanism – Cryptobiosis:
  • Enter a hibernation-like state by curling into a ball called a tun.
  • They retract legs and head into their cuticle (exoskeleton) and shut down almost all body processes.
  • Resume normal activity when favorable conditions return.

Why is ISRO taking Tardigrades to space?

• Tardigrades are the only known animals capable of surviving even in the cold vacuum of Space. 
• In 2007, a crewless Russian capsule on a European Space Agency (ESA) mission exposed some 3,000 tardigrades to the vacuum of space for 10 days, and they were left out there in low-Earth orbit. Over two-thirds of the animals survived the mission and even gave birth to offspring upon returning to Earth.
• The ISRO project will examine the revival of dormant tardigrades, count the number of eggs laid and hatched during a mission, and compare the gene expression patterns of spaceflown vs. ground control populations. 
• The research seeks to identify molecular mechanisms of resilience, potentially furthering understanding about the limits of life in extreme environments.

Source : Indian Express