The commercial sector's interest comes as many anticipate support from the Trump administration, which is eager for a first-term triumph to rally the nation the way the Apollo flights did in the late 1960s and early 1970s.

The latest to offer a proposal is Jeffrey P. Bezos, whose space company Blue Origin has been circulating a seven-page white paper to NASA leadership and President Trump's transition team about the company's interest in developing a lunar spacecraft with a lander that would touch down near a crater at the south pole where there is water and nearly continuous sunlight for solar energy. The memo urges the space agency to back an Amazon-like shipment service for the moon that would deliver gear for experiments, cargo and habitats by mid-2020, helping to enable "future human settlement" of the moon. (Bezos, the founder of Amazon.com, owns The Washington Post.)

"It is time for America to return to the Moon — this time to stay," Bezos said in response to emailed questions from The Post. "A permanently inhabited lunar settlement is a difficult and worthy objective. I sense a lot of people are excited about this."