Context:

Recently, two NASA astronauts returned to Earth from the International Space Station (ISS) after 9 months.

More on the news:

• United States astronauts Sunita Williams and Barry Wilmore went to space on board the Boeing Starliner Calypso on June 5, 2024.
• But after malfunctioning of their spacecraft, they had to remain in the ISS until their return could be arranged 

How does living in space harm the body?

Spending months in microgravity is tough on the body. 

Without Earth’s gravity, muscles shrink, bones weaken, and bodily fluids shift. 

Astronauts lose muscle mass quickly because they don't use their legs to support weight. 

Bones become fragile, and astronauts lose 1% of their bone mass each month, which is like ageing a year on Earth. 

Astronauts on missions over six months receive 10 times more radiation than on Earth. Prolonged radiation exposure is linked to higher cancer risks and possible cognitive decline.

The complete information on effects on human fertility, embryonic development and long-term space habitation spanning generations remains unknown.

• This is especially important as humankind considers future space colonization efforts.

How does the body recover back on Earth?

• Returning to Earth does not immediately undo months of strain on astronauts’ bodies. 
• As their bodies readjust to gravity, they experience balance issues, dizziness and weakened cardiovascular function.
• Even months after landing, not everything recovers. They face long-term health risks, including cancer, nerve damage and degenerative diseases.