The Space Shuttle Discovery is on its last mission ... and Colonel Eric Boe is on board the spacecraft making calls to his Nana in Florida!

The first time he called Gladys Roscoe was in 2008 during a separate mission aboard the Endeavor, but the 93-year old wasn't home because she was out square dancing!! 

This time her grandson called and Gladys was by the phone and ready to pick-up!  Click here to watch the video.