New Delhi, March 14 -- Sunita Williams' return to Earth: NASA astronauts Sunita Williams and Butch Wilmore have been 'stuck' in space for nearly nine months now.

SpaceX and the NASA, had planned on Wednesday, March 12, to launch from Florida a replacement crew of four astronauts, a mission called Crew-10, to help bring back Sunita Williams and Butch Wilmore. A last-minute issue with the rocket's ground systems, however, delayed the mission further.

When will Sunita Williams return to Earth then? Why is Crew 10 so important for the NASA astronauts return? When will the Crew 10 lift off? Here's what we know.

Sunita Williams and Butch Wilmore's space expedition, which was intended for eight days, expanded to nine months, following technic...