On last day of shuttle launch, astronaut Leroy Chiao reflects on his time in space

As the shuttle Atlantis takes off for the very last time, we're looking back at the legacy of the space shuttle program and the importance of the shuttle program in U.S. history.

Especially for astronauts who have flown in the shuttle, today is a bittersweet day when NASA closes the first chapter in human spaceflight and prepares to start a new one.

Live from Kennedy Space Center this morning, CNN's Ali Velshi talks with Leroy Chiao, an astronaut who flew on three shuttle missions and spent more than six months on the International Space Station. Chiao explains what it feels like to see the last shuttle take off.