Commercial use of water ice in craters near the lunar poles could help open the moon to long-term human settlement.

The moon is back in vogue.

The United States aims to return astronauts to the lunar surface by 2024 , and then build up a long-term, sustainable presence on Earth's nearest neighbor. The European Space Agency has repeatedly stressed a desire to establish a "moon village" in the near future, and China has crewed lunar ambitions as well.

And then there's the private sector. Companies such as Blue Origin, Moon Express and Astrobotic are building landers to deliver payloads to the lunar surface. Before too much longer, such craft may carry mining robots that first test, and then exploit, lunar resources such as water ice, which appears to be plentiful on the floors of permanently shadowed polar craters.

Related: Home on the Moon: How to Build a Lunar Colony (Infographic)

And, in case you hadn't heard, SpaceX is building a giant spaceship to ferry people to and from the moon, Mars and other solar system destinations.

Author (and longtime Space.com contributor and columnist) Leonard David looks at these coming developments and much more in his new book " Moon Rush: The New Space Race ," which was published this week by National Geographic.

Space.com recently caught up with David to talk about the book and the future of lunar exploration.

Leonard David's book "Moon Rush" was published by National Geographic on May 7, 2019. (Image credit: National Geographic)

Space.com: People have talked about returning humans to the moon for decades now, since the end of the Apollo program in the early 1970s, but it still hasn't happened. Is there something different about this moment? Or do you think the momentum we see building will stall?

Leonard David: In some ways, I'm too old and cranky, and it reminds me of other things that have happened in my lifetime, when the moon was in vogue and the program got curtailed. I lived through all the Apollo landings, and, as you know, there were a lot of other plans beyond Apollo 17. We would've gotten a lot bolder — more pinpoint landings on a lot of different parts of the moon.

But I do give credit to the Trump Administration, particularly to the Space Council being re-established . I think that's the new twist in this story — that council and the people that are on it, trying to help guide the administration to make a space program that can be stood up and withstand the test of time instead of falling apart.

Again, I've seen this before, where you get a lot of momentum going and then the monies never arrive, and things start falling apart. Without constancy of purpose, we will relinquish our goal of returning humans to the moon, and other countries are going to fill that void.

Related: Moon Base Visions: How to Build a Lunar Colony (Photos)

Space.com: About those other countries: Apollo was driven largely by a space race with the Soviet Union . Do you see something similar happening today, even if it's not so overt, with China or other nations?

David: I've kind of convinced myself that it's a little bit of a low-latency Sputnik effect . We've got all the makings of a rivalry with other countries, China being on top of the list. And I do think they have a multifaceted program that we haven't focused on. They may actually have a quite capable space-station program, as well as a moon-landing program. They're on the far side of the moon with a probe , and they're going to perhaps launch a [lunar] sample-return mission at the end of the year, depending on how the next Long March 5 launch goes, coming up in July.

It does seem to me to have all the makings of some kind of space race that we're not really cognizant of. [U.S. Vice President Mike] Pence has said "space race," so it's becoming part of the terminology of why we're going back to the moon.

The other thing is, the idea that the European Space Agency is still involved with a "moon village" and opening that up to other nations is interesting, as well as us building the Lunar Gateway , if that becomes a real program. They try to subdivide that into international involvement — kind of a mini-International Space Station.

So, you put all those pieces together — I don't know. I smell space race.

Space.com: And you've also got all the private companies involved now.

David: Exactly. When we say "space race," there are these companies now, too, with private entrepreneurs. The Israeli lander [Beresheet] crashed , but it does show us what could be forthcoming from a lot of private companies and groups.

But I do think that with that come the lawyers. [There will be] different types of governance that are going to be involved on the moon, and the lawyers are already there, sniffing around the craters. I'm not sure we know yet what is really going to happen with the legal aspect of multiple nations going, particularly when the moon is becoming carved up into projected bases. There are certain points on the moon where you want to be, and you want to be there first, before anybody else.

Related: Who Owns the Moon? A Space Lawyer Answers

Space.com: Yeah, that's going to be tricky. There's a lot of talk about mining lunar resources — not just water ice, but also maybe minerals, and perhaps even helium-3. And if there really are billions and billions of dollars to be made there, then there are going to be lots of fights about who owns what. Is it going to be another land rush? We're going to see that play out.

David: That's what I think. You can see that there's going to be tension; it almost seems like "We're going to do whatever we want to do and then ask for forgiveness later."

We've seen this before — claim jumpers and whatever — when you go back in history.

Space.com: So, with all of this going on, do you see something big happening with lunar exploration in the next 10 to 20 years?

David: I do. I think some of it's going to depend on what we find there with the first sorties of humans and more robotic exploration. This lunar ice question is questionable; we're not sure what we're dealing with there. We're not sure what the consistency is, how hard it will be to drag out of the bottom of craters that are ultracold. Can you do that economically?

So, we need a lot more data. If you're trying to predicate the whole economic value of the moon, you better know what you're going to go and dig out.

And there's one thing that's lurking — I kind of touched on it, but I wish would've written more about it — and that's the military utility of the moon . I think that's a sleeper thing. You can see even the generals starting to talk about cislunar space. So, this is another higher ground than where we have been in the past, and now we're going to have cislunar things that the military is very interested in. I think that's another one that's coming that we'll have to keep an eye on.

And then you get into — let's say you do have an economic windfall on the moon. It's to a country's benefit to protect it — make sure nobody tampers with anything. That has all the makings of the conflicts we get down here on Earth.

Space.com: Can we take any lessons about this next giant leap from Apollo? Apollo was so long ago now, it's almost out of living memory. And what we want to do on the moon next is very different — go and stay, not just plant flags and leave footprints.

David: Unfortunately, as the astronauts die — and these ancient astronauts are dropping; there are only a handful left — the experience of actually being there is sort of getting lost.

A lot of people don't remember Apollo. So, there's an issue of recalling all the things that were actually accomplished. Not just planting flags — setting up instruments, and what kind of data was accumulated, and how hard that environment was to work in, particularly the dust. The dust issue is the one that's always held out as, "This is dangerous." There are ways to mitigate it; people have some ideas. I think new technologies will allow us to counter those kinds of issues.

[Apollo 17 astronaut Harrison] " Jack" Schmitt is a great example. He's trying to go back and document every footstep he took from a geological perspective. He's trying to document the entire benefit of him, as a geologist, going there. And memories are going to fade.

You look at some of the problems we're going to have in trying to establish an economic foothold on the moon; the drawings are cheap. People have a lot of PowerPoints [presentations], how it's going to look. But doing experiments here on Earth and then thinking that's the way it's going to work on the moon — it's probably not going to happen. You're going to have to go to the moon and figure out, "Well, that technique does not work." You have to go there and try out stuff.

Related: NASA's 17 Apollo Moon Missions in Pictures

Space.com: And lots of the tech we'll test out there will help us push even farther out. NASA stresses that the moon is a stepping-stone to the ultimate destination for people — Mars.

David: I'm big on the stepping-stone thing. The Mercury and Gemini missions were all stepping-stones to proving out Apollo technology. So, I do see this lunar outpost as something important to deep-space habitation.

To me, the stepping-stones are very critical in this. NASA needs a steppingstone program, because they're not ready. We've been in low-Earth orbit so long, we've lost that feeling, that moon feeling, how to pull off deep-space exploration. Testing the hardware. And we're still learning about the human body, thanks to the space station program.

But the idea that the moon is a "been there, done that" world is flat wrong. We haven't been to that many places on the moon.

I look at it like Seward's Folly, when we purchased Alaska. That was very contentious in Congress at the time, why we were spending that much money. But we didn't know what that wilderness was going to provide. The surprises came later, and that was a windfall for the country instead of some folly. So, maybe that's what the moon may represent — something like wilderness that we're not quite sure what's there yet, and we need to go there and find out, using humans and robots.

We're going to find things on the moon that will surprise us. I'm ready to be surprised.

Related: Moon Master: An Easy Quiz for Lunatics

Space.com: Is there anything else you'd like to mention?

David:I hope the book stirs up conversation. Anytime you write these things, you want people to walk away with maybe more questions than they had going in.

Another thing is the ethics of it all. You've got ethics at some level here on the law side, with who's going to be where and how we can operate together on the moon. Are we all going to hold hands, or will there be claim jumpers? That kind of stuff.

And then you've got some people — it didn't wind up in the book, but I wrote it all — some of the advertising people want to do things with the moon. I've seen some pretty wild ideas — you know, carving out parts of the moon to make a logo so everybody can see it on Earth. That's the kind of thing that makes people in the audience wince when you even bring it up.

And then there's the whole preservation of the moon sites. If you really think, and I do, that tourists will be going to the moon in the future, it'd be nice to visit the Apollo 11 or 17 [landing sites] or whatever, and use those as part of the tourist campaign. There's a pretty good amount of work going on about making the moon a historical site and trying to preserve that for future visitors.

You can learn more about "Moon Rush," and purchase the book, via National Geographic . The book is also available on Amazon.com .