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Tap into the experiences of NASA’s technical workforce as they develop missions to explore distant worlds—from the Moon to Mars, from Titan to Psyche. Learn how they advance technology to make aviation on Earth faster, quieter and more fuel efficient. Each biweekly episode celebrates program and project managers, engineers, scientists and thought leaders working on multiple fronts to advance aeronautics and space exploration in a bold new era of discovery. New episodes are released bi-weekly on Wednesdays. 

VIPER Project Manager Dan Andrews discusses the lunar rover’s upcoming mission to look for water ice on the Moon.

NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) is a golf-cart-sized, mobile robot that will go to one of the Moon’s poles to get a close-up view of the location and concentration of water ice that could eventually be harvested to sustain human exploration on the Moon, Mars and beyond. Planned for delivery to the lunar surface by 2023 under NASA’s Commercial Lunar Payload Services initiative, VIPER represents the first resource mapping mission on another celestial body.

In this episode of Small Steps, Giant Leaps, you’ll learn about:

  • How VIPER will help pave the way for a lunar outpost
  • VIPER’s science instruments and how they work
  • The VIPER execution model that could lead to commercially provided rovers


Related Resources



Commercial Lunar Payload Services


Lunar Prospector


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Creativity and Innovation (APPEL-C&I)

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Crucial Conversations (APPEL-CC)


Dan Andrews Credit: NASA

Dan Andrews
Credit: NASA

Dan Andrews is the Director of Engineering at NASA’s Ames Research Center and the Volatiles Investigating Polar Exploration Rover (VIPER) Project Manager. Andrews works closely with NASA Headquarters to develop the first U.S. robotic rover mission to the Moon. He also led the LCROSS mission that confirmed the presence of billions of gallons of water ice on the South Pole of the Moon. Andrews started his career at Ames as an automation and controls engineer working on many diverse robotic technology demonstration projects, including development of the Personal Satellite Assistant (PSA) Project — a free-flying robot astronaut assistant that was named one of the “50 Best Robots Ever” by Wired Magazine. Andrews earned a bachelor’s degree in electrical engineering from San Jose State University and a master’s in mechanical engineering from Stanford University.


Dan Andrews: If you think you understand what an off-world rover looks like, your mind is going to be blown a little bit.

There’s so much about VIPER that is innovative and a different approach.

It will ultimately, long after my time, be the pathfinding for a whole commercial ecosystem associated with the Moon, enabling humans to go further and further into the solar system more quickly and more cost effectively.

Deana Nunley (Host): Welcome back to Small Steps, Giant Leaps, a NASA APPEL Knowledge Services podcast that taps into project experiences to share best practices, lessons learned and novel ideas.

I’m Deana Nunley.

NASA’s Volatiles Investigating Polar Exploration Rover, or VIPER, is a mobile robot that will look for water ice on the Moon.

VIPER Project Manager Dan Andrews, who also serves as Director of Engineering at NASA’s Ames Research Center, is with us today to discuss the new lunar rover.

Dan, thank you for joining us on the podcast.

Andrews: Thank you very much. My pleasure.

Host: Could you give us an overview and background of the VIPER mission?

Andrews: Yeah. The VIPER mission is a really cool lunar mission. It’s following on the heels of some really interesting data that goes all the way back to the ’90s, believe it or not. There were two missions, the Clementine mission in ’94 and the Lunar Prospector mission in ’98. They were very different missions, different customers, different purposes, but they both saw some interesting things happening in the polar regions of the Moon.

As people started looking at that data and correlating it, they started wondering about this idea of there potentially being water ice in the polar regions of the Moon, which, of course, blew the minds of everybody because how could there possibly be. We have the whole Apollo mission series, and there was no indication at all that there would be water ice in the polar regions. These two missions couldn’t confirm that there was water ice there, but that would just be a potential explanation for what they were seeing with neutron counts and some other things that they were looking at.

So, we needed a mission to go and answer that. And in 2009 we had another mission called LCROSS, which was short for the Lunar Crater Observation and Sensing Satellite, and I was the project manager for that mission. What that mission was all about was trying to confirm was the strange signals that seemed to be indicating that there was elevated hydrogen in the polar regions of the Moon, was actually in the form of water ice. So we did that mission, and fast-forward to the end of it, we were able to confirm through witnessing actual water ice crystals and water vapor the presence of water ice there, which basically rewrote the books on the Moon.

So VIPER now enters the picture as the mission who is going to go there – it’s a rover-based mission – and actually attempt to determine the distribution and nature of the water ice. How is it distributed horizontally? How deep might it be? Is it chunky or sheets or ice? Is it frosty? Those types of things, now that we know that water ice is really there. So it’s a pretty exciting and super important mission.

Host: What will VIPER do that hasn’t been done before?

Andrews: VIPER is going to be basically answering the question of whether or not it’s practical to live off the land from the standpoint of water and water ice on the Moon. To help explain that a little bit, water, of course, building blocks of life and so forth. But we’re not so much interested in it from a detection of life point of view. There’s other activities like that within NASA. We’re interested in it as a resource because, of course, water is H2O. Water itself is useful to sustain humans, to grow crops.

If you were to have an outpost there, which is ultimately the plan with the Artemis Program, you could use it for manufacturing. You could take the lunar regolith, which is basically Moon dirt, and add water to that and add a kiln, an oven of some sort, and you could actually make lunar bricks for construction or other materials.

But even more interesting than those possibilities are, since water is of course hydrogen and oxygen, if you could break the water into hydrogen and oxygen, now you have oxygen to breathe, which, again, helps with the sustainment. But hydrogen acts as a rocket fuel. So when you think about it, the rocket that’s going to be taking VIPER to the Moon is probably going to be based on hydrogen and oxygen tanks put together within a rocket. That is a propellant.

So, think about the possibility, if you fast-forward in time, if VIPER is able to confirm where the water ice is and its nature, so that follow-on missions could go in and harvest that water, you have the possibility of, in effect, a gas station at the Moon, not just for lunar use, but you could imagine going to the Moon and gassing up on your way to Mars, or on your way to Saturn or Venus or any other number of locations within the solar system.

Host: So interesting. How significant is the VIPER mission in humanity’s return to the Moon and future Mars exploration?

Andrews: It’s pretty important. When we were taking an early look at VIPER and Resource Prospector, the mission activity that was preceding it, one of the things that senior leaders within the administration were looking for was understanding whether or not they should be planning around utilizing the resources of the Moon to go on to Mars in particular.

As most of your listeners are probably well aware, it’s a very expensive and daunting thing to go to Mars with humans. It’s hard enough to do it with robotics, even much, much harder to do it with humans. So if we have to bring everything that we need on Mars, which includes not only the stuff to sustain humans, but all the propellant, incredible amounts of propellant, if we have to bring all that from Earth, that’s not only challenging from a logistics point of view. It’s incredibly expensive. You’re having to leave Earth’s gravity well, which is six times stronger than the gravity on the Moon.

So, if there was any way that we could harvest water and turn it into propellant at the Moon and say – can you envision a necklace, say a satellite orbit of tanks that are sitting in orbit? Think of them as gas stations, and they’re being continuously filled from the surface of the Moon. The North Pole and the South Pole are continuously replenishing them. Then you can gas up, if you will, at the Moon. Then you only need to bring enough propellant from Earth to get you to the Moon, as opposed to all the way to Mars or to whatever your destination might be.

You can gas up at the Moon and go from there to your destination. You have a much smaller gravity well at the Moon. You have fuel that you didn’t have to take the effort to bring from Earth, which is costly, expensive, requires many, many launch vehicles. It’s just a win all the way around. So, understanding how practical that is begins with the VIPER mission.

Host: Could you describe the science instruments on the rover?

Andrews: Yeah. We have three basic instruments and then a drill. I’ll start with the drill, something called the TRIDENT drill. It is commercially provided by Honeybee Robotics, located in Southern California. They are a company who have come up with a number of different drills for uses on Mars, the Moon, other extraterrestrial locations. So, that looks like it’s a good fit, a solid drill and it’s just perfect for us.

Then, the VIPER mission has three different sensing instruments to help us with this. So let me back up a little bit and explain how VIPER works.

VIPER, of course, is a roving mission. It’s going to go to either the North or the South Pole. Both of those would work, because that’s where the volatiles and water resources are to be located. We’re going to be roving around using a neutron spectrometer that’s hanging off of the front of the rover. Think of that as our divining rod. It has the ability to look through about a meter, three feet or so of soil. It can basically see through the soil and look for water ice. Now it does that by counting neutrons that are coming out of the soil, but, in effect, we can relate that relative flux of neutrons coming out of the soil to water ice and hydrogen levels.

So as we’re driving along, we’re measuring, measuring, measuring as we go with this neutron spectrometer. When we hit a particularly wet location that it’s detecting somewhere down in that three feet of soil, that there’s water ice, then we can go ahead and position ourselves as a rover over that location, and put the drill down into the soil in 10 centimeter chunks. It can go as much as one meter deep, and bringing up the materials that are then looked at by two other instruments that we have to fill out the suite of three.

One is a near-infrared spectrometer and the other is a mass spectrometer. So you’re hearing spectrometer, spectrometer, spectrometer all over the place, and of course that’s with great purpose. Spectrometers are very good at detecting the chemical composition and the nature of what they’re looking at.

So the neutron spectrometer is just finding, “Okay, there’s ice somewhere in the three feet below me,” but it doesn’t really tell you the nature of it, its concentration. It doesn’t even tell you how deep it is. It just tells you that within that three feet there’s water ice there.

Then the drill comes in, actually pulls it up, and the mass spectrometer and near-infrared spectrometer are actually looking as the material is being drilled up. You can imagine a pile forming where the drill bit is going into the soil, and they are looking at exactly what I described, the chemical nature, the concentrations as a function of depth, so that we have a really good understanding of where that water ice is located, its nature. Is it chunky and very, very icy at a certain depth, or is it spread evenly like a cup full of salt and pepper, and it’s just spread evenly throughout? There are lots of theories about how it likely is. VIPER’s job is to verify what it really is.

Host: Then as you’re starting to get this data, how quickly can you react to that while the mission is actually happening? And what will the scientists on the ground be doing during the mission?

Andrews: Great question. We have a semiautonomous mode of operation. Now, your listeners will probably know that to communicate with Mars takes a decent amount of time delay, between the signal leaving Earth and going to Mars and then, of course, a reply coming back. Just the speed of light in that distance, it takes a while.

Over on the Moon, we’re much closer. There’s still a delay, but it’s faster. So it opens up the possibility that instead of driving like we do on Mars, which is we send a whole series of commands and then upload them, and then come back the next day and see if they’re executed and what was discovered, we can be more interactive with the Moon, but not joystick interactive. What I mean by that is this won’t be like playing a video game, because we still estimate there could be as much as 10 or 11 or 12 seconds of delay between the Earth and the Moon, by the time it gets through antennas and routed along the ground to the control system and so forth.

So, we’re going to do semiautonomous operations. What that means is the drivers on the ground, on Earth, are sending commands on where to go with the rover. But what they’re doing is sending waypoint commands. What that means is if I’m the rover here sitting at my desk, I might tell the rover to go across the room, 10 feet away, and go to that location, and then I’ll let the rover figure out how to get there. So there’s the autonomous part, but I’ll still treating it like I’m baiting it with a carrot, so, “Go over here. Okay. Now go over here. Okay. Now go over there.”

So in between each of those moves, you’re asking about what the scientists are doing. They’re looking at the neutron spectrometer data that’s flying back to Earth live over this movement of the rover, and they’re able to react live to what they find. So let’s say, back in my example of moving through my room, I told it to move 10 feet away, to the opposite side of my room, but along the way, we find that at the five-foot point there’s a really interesting set of measurements coming off the neutron spectrometer. We can go ahead and go back to that location and use the drill, and do whatever you’d like to do around that area to help us understand the nature of the water ice and its distribution. So it’s pretty interactive, but by way of a waypoint driving methodology.

Host: How will VIPER be delivered to the surface of the Moon?

Andrews: There’s so much about VIPER that is innovative and a different approach. The LCROSS mission, when we were managing that, was a very different approach, very streamlined and very cost-effective for NASA technicians. We’re bringing the same thing to this mission, and another interesting facet of VIPER is your question. How are we getting to the Moon?

Normally, the way NASA would do is it would acquire a launch vehicle, the rocket that helps it leave Earth. We would get our ride to the Moon and then our spacecraft would take over from there. We would do the landing. We would separate the rover from the lander, once it had landed, and off we go. Very traditional.

Instead, we’re actually going to be relying on the commercial world through what’s called the CLPS program. Now CLPS is C-L-P-S. It stands for Commercial Lunar Payload Services. What we’re doing is really innovative. We are going to have a group of candidate contractors, commercial contractors who are already preapproved. At this time, as I’m speaking with you, there are 14 different companies who are already approved on this contract.

Then we issue tasks. We, NASA, issue tasks to them. They could be very small tasks, delivering a small instrument to space, to the surface of the Moon, to orbit a Moon, whatever we want. Or it could be something much larger like VIPER. So we’re going to use this CLPS program to deliver VIPER to the surface of the Moon.

What’s really interesting, for those who are quite familiar with how this normally works, what we’re basically going to be doing is telling the commercial parties, and they’re proposing back to us how they would do it, “You’re going to get the VIPER rover on date X. Then I want to be rolling off the surface of the Moon at location XY on date Z.” Then they work out everything in between those two possibilities.

So they get to figure out when they’re going to launch. They get to figure out what launch vehicle they go on. They get to design the spacecraft that will carry us from the journey of launching from Earth to landing down on the surface. They could decide if they want to go into lunar orbit or directly head to the Moon and directly land when they get there.

We officially don’t care. We just know that we’re going to give you the rover on this date, and we want to be rolling off on the surface of the Moon on this other date. I really think of it as kind of like an Uber ride to the Moon.

Host: That’s very different than what we’ve been used to traditionally, right.

Andrews: Yep.

Host: Dan, what’s it like to be the project manager for VIPER?

Andrews: Well, pretty awesome, let me just say that. I’ve had a pretty blessed career here at NASA. This is my 33rd year. Like I said, I got to lead the LCROSS mission, which really rewrote the books on the nature of the Moon. Now, I’m having the opportunity to go and lead the VIPER mission, which is going to go and follow-up on the LCROSS and LRO and Chandrayaan missions, all who contributed to learning of the Moon and actually ground-truth that water ice question.

So to be able to have a really killer team like we have, multiple centers, the best of the best all working on this effort that will ultimately, long after my time, be the pathfinding for a whole commercial ecosystem associated with the Moon, enabling humans to go further and further into the solar system more quickly and more cost effectively. I mean what’s not to like about that. That’s pretty fantastic.

Host: It does sound fantastic. What have you learned as the project manager of VIPER and its predecessors that could helpful to other NASA PMs?

Andrews: I’m a pretty patient guy and this whole process has tried even my patience. What I mean by that is it’s no easy feat to get a mission green-lighted, approved, because there are so many interesting things that the agency could be doing with its money, and they’re all kind of competing with each other. So, it’s a tough environment to advocate for what you think makes really good sense in the best interest of the agency. That’s why even getting to the point that we are now, which is the beginning of a mission, an approved mission is quite an accomplishment.

From a team point of view though, project manager, I have always felt that having a completely open and candid environment in which the team works is your best elixir for success. I mean it’s really, really important that when you get this great group of people together that they feel like they’re getting all the information, what’s really going on. These are all grownups. Treat them as such. Give them as much information as you can. Try to decrease the noise. There’s always a lot of reporting noise and questions that come down. Try not to bother them with that. That’s your job.

Then create an environment where they can really be creative, because it really fits that old adage about the sum of the parts and the greatness of a team. If everyone on the team feels that they are indebted and willingly indebted to all the other parts of the team, really amazing things happen. Everyone feels that they’ve got to bring their A game, and that it will be worthwhile when the mission culminates. So I’m very pleased with all that.

Host: Are the collaborative efforts for the VIPER mission similar to other collaborations across the agency?

Andrews: I think so. What we’ve done is the VIPER mission is being led out of NASA Ames Research Center, but it’s in very close coupling with NASA Johnson. The rover is actually being built at NASA Johnson and the flight software for the rover is being done at NASA Ames, because we both have some good experience in those areas.

The instruments, two of them are being designed at NASA Ames, one of them at NASA Kennedy, the solo mass spectrometers at NASA Kennedy. Then I mentioned earlier that we’re actually buying a commercial drill. So NASA isn’t even developing that. It’s buying it off the shelf.

Then we have other relationships, for example, with NASA Glenn. NASA Glenn has a really good facility up there for testing mobility systems, rover systems, wheel designs and so forth. So we’re really using the best from around the agency, both the best people and the best infrastructure and capabilities, to try and buy down the risk of this super-interesting mission before we go to actually execute it.

Host: It has been super-interesting, and talking with you and hearing about it has really been interesting. I really do appreciate you taking time to join us today on the podcast.

Andrews: Absolutely, great fun.

Host: Do you have any closing thoughts?

Andrews: Well, I just want everyone to watch along as the VIPER mission proceeds through its design work. We’re going to have some really interesting videos during development. If you think you understand what an off-world rover looks like, your mind is going to be blown a little bit because this rover actually can do what we call a turtle swim. It rolls like rovers do. That’s its normal operation, but we actually came up with a way that if we find ourselves in really soft soil, where you could easily see a rover getting stuck just doing rolling, we actually have a way to kind of swim or crawl out of it. I hope we don’t have to use it, because that means things are challenging on the mission, but it’s nice that we have that and it’s like nothing anyone has ever seen before.

I think our execution model is also going to be very different. The agency is always looking for how it can be increasingly more relevant to current capabilities and technologies, and our team has already demonstrated the ability to push us forward, to kind of path-find that.

Frankly, this CLPS contract is yet another example of it. The moment NASA is able to acquire a capability from industry, it should not be competing with that and it has no interest in competing with that. I joke with people that whenever I go on travel, I don’t fly on a NASA jet. I fly in coach on a commercial airliner like everybody else. That’s because the commercial world has brought cost efficiencies, savings, and all that to it to make that the smart thing to do.

So, maybe the mission that will follow behind VIPER will be one that’s commercially provided. Maybe it will be a commercially provided rover. That’s great. If industry is ready to do that, then let’s path-find on that route, and we’ll spend our activities within NASA doing the really hard and very risky stuff that isn’t really possible by for-profit commercial industry. We’ll just always keep that as our divining rod as an agency going forward, and I think we’ll get great things done that way.

Host: Links to topics discussed during our conversation, along with Dan’s bio and a show transcript, are available at

Dan talked about the Commercial Lunar Payload Services initiative that will deliver VIPER to the Moon. We’ll get to learn more about CLPS during our next episode when Steve Clarke, the NASA Science Mission Directorate’s Deputy Associate Administrator for Exploration, joins us on the podcast.

If you have ideas for guests or interview topics, please let us know on Twitter at NASA APPEL and use the hashtag SmallStepsGiantLeaps.

As always, thanks for listening.