Space Watchers Critique President Obama's Proposal for NASA's Future, PBS NewsHour

"Keith Cowing, editor, NASA Watch: It's a paradigm-shifting proposal. It has matured a little over the past few months and will continue to mature. But what it does overall is challenge the status quo as to how America explores space. And that involves making some difficult decisions. It's changing the policy begun by President Bush with the Constellation program, and it says we want to go further in terms of using private sector than ever before.

Tom Young, former Lockheed Martin executive vice president and former NASA official: I think it's a significant mistake. Not because I don't think the aerospace industry is enormously capable, but I think it's not capable of doing something as challenging as humans in space by itself. I think the probability of it being unsuccessful is very high."