For $150 billion, the National Aeronautics and Space Administrationcould have sent astronauts back to the Moon. The Obama administration judged that too expensive, and in September, Congress agreed to cancel the program.

For a fraction of that — less than $200 million, along with about $250 million for a rocket — NASA engineers at the Johnson Space Center in Houston say they can safely send a humanoid robot to the Moon. And they say they could accomplish that in a thousand days.