NASA's Next Frontier

Forty years later, we have problems closer to home. But space still beckons. The US has competitors on the high frontier. And American space enthusiasts are debating where the next big push should be. Back to the Moon – maybe to build a giant solar energy station? Or straight on to Mars – maybe to create a second Earth.

This hour, On Point: Moon versus Mars, and what comes next in space.

You can join the conversation. Tell us what you think — here on this page, on Twitter, and on Facebook.Guests:

Robert Zubrin is president of Pioneer Astronautics, an aerospace research and design company. He previously worked as an engineer at Lockheed Martin. He is the author of “The Case for Mars: The Plan to Settle the Red Planet and Why We Must” and "How to Live on Mars: A Trusty Guidebook to Surviving and Thriving on the Red Planet."

David Kring is Senior Staff Scientist at Universities Space Research Association's Lunar and Planetary Institute in Houston, TX. He is the former director of the NASA Space Imagery Center at the University of Arizona.

Harrison Schmitt is a crewmember from the 1975 Apollo 17 lunar mission, and a former New Mexico Senator.

Listen to NPR's report on the missing Apollo 11 tapes and watch restored videos of Neil Armstrong and Buzz Aldrin walking on the moon and planting the U.S. flag.