India, Feb. 18 -- Stranded astronauts Sunita Williams and Butch Wilmore are expected to return to Earth on March 19. However, after their return, the two astronauts could have a hard time readjusting to Earth's gravity. In fact, gravity could feel like a punishing force as Williams and Wilmore's bodies readapt to life on earth.

Williams and Wilmore have already spent more than eight months in microgravity in space. Wilmore revealed that gravity will be the biggest challenge for them after they return. "Gravity is really tough, and that's what we feel when we get back," he told CNN. "Gravity starts pulling everything to lower extremities; fluids will be pulled down, and even lifting a pencil will feel like a workout."

Williams has also e...