India, March 20 -- Astronauts Sunita Williams and Butch Wilmore should be handed plastic cups to drink instead of normal cutlery as they recover their muscle strength, astrophysicist Neil deGrasse Tyson has said.

In an interview with NDTV, Tyson said that the two astronauts, who returned to Earth from the International Space Station (ISS) after a nine-month delay, will need time to readjust to Earth's gravity.

"There is no reason to think their muscles will not be able to hold them up... on the ISS, they have many ways to exercise," Neil deGrasse Tyson told NDTV.

"The difference is... when you spend this much time being weightless, your ability to orient for what is 'up' and 'down' is compromised because you never had to use these tool...