On Wednesday, NASA engineers were upgrading the space station's command and control software when communications collapsed as they made the transition from the main computer to a backup system to complete the software load.
When the orbiter flew over Russian ground stations, NASA was able to use the stations' antennas to connect with the crew and tell them to connect another computer to restore communications. NASA lost contact with the space station for nearly three hours.
Hadfield, said the astronauts -- orbiting 250 miles above the Earth - didn't panic.
"We trained for many, many years and we've been together as a crew for a while," he noted." We're ready for many things. We worked together as a crew following the procedures as to what to do. The people on the ground were scrambling and working hard... It wasn't panic. We were working together as a team. It's just things that happen in space."
Kevin Ford, a NASA astronaut and space station commander, fielded a question about what students should study if they want to become astronauts or work in the aeronautics field.
"It's almost overwhelming all the choices that are offered to you," he said. "I love math. And I love physics and I had very enthusiastic teachers... We have a life support system onboard that is very chemistry intensive. We talk chemistry every day. We use math every day. It's a lot of complicated science to make this all work."
Ford added that students should take all the classes they can. " You might need them all if you end up in the space business," he said.
Ford also noted that the first thing that inspired him to become an astronaut was reading the book Carrying the Fire: An Astronaut's Journeys, written by astronaut Michael Collins, who was on the Apollo 11 mission to the moon.
"I really just fell in love with that profession because of that book," he said. "What he did, the trip he took to the moon with Neil Armstrong and Buzz Aldrin, that really started it all off for me."
So which scientist would the astronauts like to take into space with them?
For Flight Engineer Tom Marshburn, the answer was simple -- physicist and mathematician Isaac Newton.
"We see what he could only imagine," said Marshburn said. "It's really hard to believe that he could imagine these things, and it would be great if he could see it."