Our cover story this month started with what seemed like a simple question: Why is it so hard to get back to the moon? I mean, obviously rocket science is rocket science—complex, dangerous, pitiless. But we figured it out more than 50 years ago, which is eons ago in computer years. Scientific American contributing editor Sarah Scoles explores the surprising technological and social reasons that the Artemis II flight, scheduled to lift off next year (but don’t mark your calendar), seems so much more challenging than the Apollo missions.