President thanks shuttle workers

In a phone conversation this afternoon with 10 astronauts and cosmonauts on the International Space Station, President Barack Obama thanked the workers who have helped fly 135 shuttle missions over the past 30 years and promised an exciting new era in human spaceflight.

"I know that there have been thousands who have poured their hearts and souls into America’s space shuttle program over the last three decades that are following this journey with special interest," Obama said. "To them and all the men and women of NASA, I want to say thank you. You helped our country lead the space age and you continue to inspire us."

Obama said he had watched Atlantis' launch last Friday on TV in the Oval Office. He referenced post-shuttle plans to develop the capability to explore the moon, asteroids or Mars and competition to develop commercial space taxis to transport astronauts to the station.

The Atlantis crew is leaving an American flag on the station that was flown on the first shuttle mission in April 1981. It will be turned over to members of the first crew to arrive at the station on a commercial spacecraft.

"I understand it’s going to be sort of like a capture the flag moment here for commercial spaceflight," the president said. "So good luck to whoever grabs that flag."

"That's an excellent point, sir," replied Atlantis commander Chris Ferguson. "We sure hope to see some of our commercial partners climbing on board really soon."

The call from the Oval Office -- Obama's fourth to a shuttle crew in orbit -- came on the 36th anniversary of the Apollo-Soyuz Test Project, the first cooperative space mission between the U.S. and Soviet Union.

"It’s pretty exciting to know that American astronauts and Russian cosmonauts aren’t just shaking hands 36 years later, but are working every day with partners from other nations to represent humankind coming together in space," he said.

"We are more than just representatives of each country," replied cosmonaut Sergei Volkov. "We are one big family."

Obama joked that the joint crews needed to behave like a family to handle tight quarters and limited bathroom availability, saying the First Lady and his two daughters often crowded him out of the way.

He opened the call by joking that he had been trying to order a pizza and was surprised to find his call answered in space.

"While this mission marks the final flight of the space shuttle program, it also ushers in an exciting new era to push the frontiers of space exploration and human spaceflight," Obama said in closing.

"Congratulations to NASA, to all our international partners and all of the personnel past and prsent who have spent countless hours and untold effort in making the space shuttle and the International Space Station a unique part of our history."