The record time for a single trip to space is 437 days and it is held by a Russian astronaut. For the USA the record time is 371 days. The longest cumulative time for an astronaut is 1.111 days.
Research say that prolonged periods in space alter our muscles, brain and bacteria.
Astronauts after a long time in space need to acclimatize to Earth’s gravity.
- Muscle and bone mass diminish in space, especially the ones that maintain our posture. In 2 weeks their mass can reduce up to 20% and in 6 months, 30%.
- Bones lose strength. They loose 1-2% of their mass every month. And it takes up to 4 years to return to normal when back to Earth.
- Astronauts in space grow taller due to lack of gravity. This causes back problems.
- Eyesight reduces due to flashes of light causes by cosmic rays and solar particles. This is also because of altered blood circulation in their head due to lack of gravity.
- Neural shuffling due to altered connectivity in parts of the brain. This reduces the accuracy of their performance.
- DNA damage
Astronauts exercise up to 2.5 hours every day when in space to reduce these effects.
[Source: www.bbc.com]
