Flip-flop, or policy evolution? Presidential candidates Barack Obama and John McCain are under fire for changing their positions on Iraq, domestic spying, and offshore drilling. But when does a change in position constitute a "flip-flop?"9:06 a.m.
David Sirota: Political reporter and syndicated columnist, author of "The Uprising."
Allan Lichtman: Political historian at American University in Washington, DC and author of several books, including "The 13 Keys to the Presidency." His most recent book is "White Protestant Nation: The Rise of the American Conservative Movement."
NASA turns 50 Fifty years ago this summer, in response to the Russian launch of the Sputnik satellite, President Eisenhower created the National Aeronautics and Space Administration.
Midmorning looks back at NASA's 50 years, from the triumph of the moon landing to the tragedy of two space shuttle disasters.10:06 a.m.
John Logsdon: Director of the Space Policy Institute at George Washington University.
Rick Tumlinson: Co-founder of the Space Frontier Foundation and chairman of Orbital Outfitters.