The 50th anniversary of the moon landing has rekindled some of our collective wonder at putting actual human bodies on solid footing in space—but will that translate into action once the nostalgia fades? And if it does, what should our goal be? The moon? Mars? Beyond? What’s next?  There's something about putting real people in space that robots can't replace—even if for many missions they are far more effective. But without a Cold War to push a frantic space race, what will drive humanity's next ambitious adventure? GUEST: Michael Wall, senior writer, Space.com; Author of Out There