ASU KEDtalk: Hunting for hydrogen, a moonshot

Back to top

Craig Hardgrove tells us how the first self-propelled, shoebox-sized spacecraft could reveal the whereabouts of water on the moon and what that means to Earthlings. He also explains why small spacecraft allow us to take bigger risks.

Sep. 19, 2018

Video transcript

Hi, I’m Craig Hardgrove and I’m leading a team of researchers that’s sending this spacecraft to the Moon. This isn’t a scaled-down version. This is the actual size of our spacecraft. It’s called the Lunar Polar Hydrogen Mapper, LunaH-Map for short. LunaH-Map will launch on one of the most powerful rockets ever built by NASA and this tiny spacecraft will propel itself into lunar orbit using its own propulsion system, which is a first for a spacecraft this small. And as with any first, it’s also very risky. I want to tell you about this mission, why we’re going to the Moon, and why it's worth the risk.  

We're sending LunaH-Map to the Moon to sniff out just how much hydrogen is just beneath the surface. We’re looking for hydrogen because it’s a key component of water. Water on the Moon is geologically interesting… how did it get there? And it’s also important for future human exploration since it could be used as fuel. The Moon could be a jumping off point for the rest of the solar system. But, the Moon is a harsh place, it barely has any atmosphere at all, and the temperature can change by more than 100 degrees from day to night. In that type of environment, any ice or water that’s hit by sunlight would immediately be lost to space. But there’s a lot of scientific evidence that suggests water-ice could be present on the Moon within special, eternally dark crater floors at the south pole. These regions are in permanent shadow, and are some of the coldest places of the solar system. And that’s where LunaH-Map is headed.

LunaH-Map will carry a tiny instrument called a neutron detector, which is sensitive to the low energy neutrons leaking out of the top meter of the moon’s surface. We can use that total number of neutrons to determine how much hydrogen is trapped below, and that too is something that has never before attempted with a spacecraft this small.  
But in order to improve upon previous measurements of ice at the Moon’s poles, LunaH-Map needs to get close to the Moon’s surface, really really close. It turns out we need to be about 30,000ft above the surface, which is the typical cruising altitude of a commercial airplane – but we need to make our measurements while orbiting the Moon at over 4000 miles/hour—8 times faster than a typical airplane. All of this is, you guessed it, a first for a spacecraft this small.  

You might reasonably wonder where an audacious idea like a shoebox-sized spacecraft capable of doing all this came from?  

About 10 years ago, a university professor wanted to come up with class projects for his engineering students. The idea was to have them build small, functional benchtop components that might be used on a spacecraft, with the added engineering challenge of making them fit into a very tiny box. They were just student learning tools and demonstrations. When thinking about the dimensions of the tiny box he decided on a beanie-baby box, 10 x 10 x 10cm. He called them CubeSats. Surely, he thought, something this small would never fly into space and actually do anything useful. But as a student training exercise they were perfect, and the idea of CubeSats was a success. Universities across the country adopted CubeSats, and they became a successful teaching tool and development platform. Perhaps they were too successful… Piece by piece, over the last ten years, the components that make up LunaH-Map have been developed at, or in partnership with, universities, and their students, faculty and staff. Over the years, if the students were lucky their CubeSats would be launched into low-Earth orbit to test the student’s designs in space. They wound up not just testing designs, but developing new miniaturized technologies.  

Eventually, university students developed radios, instruments, reaction wheels, propulsion systems, and many other components until someone asked a really good question. Don’t all these components put together make an interplanetary spacecraft? And they do, as long as we accept the inherent risk of any new technology. 

Take a different industry from our own lives for example, smartphones. No one gives up on smart phones entirely if there are bugs in the first version. New technology always improves over time. 

But the first version is always a little risky and it’s a funny thing that happens when you start accepting risk. And accepting a lot of it. With a risky spacecraft, we can do risky things, things we wouldn’t normally do on a typical, big NASA mission that takes decades to design, build and fly. Would you risk your spacecraft after a decade of work? It’s not likely. But with shorter development times, smaller teams, and lower costs it allows you to actually embrace the risk, and hopefully reap the rewards. In fact, I’d argue that this is fundamental to what makes these tiny missions like these worth doing.  

You might remember probe droids from Star Wars, expendable robots deployed to capture unique, hard-to-get data about, say, the Rebel base. Imagine if we had a dozen or more tiny probes on each and every NASA mission. They could fly low over the icy surface of Europa, getting closer than any large spacecraft would ever think about. Or a tiny spacecraft could transmit valuable data from the atmosphere of Venus on descent, just before burning up or being crushed by the intense pressure. These probes could act as interplanetary scouts, deploying from the primary spacecraft, and maneuvering to intersect with asteroids that no spacecraft has ever visited. But these are just a few examples of the types of risky but highly rewarding missions that these tiny probes might take on as we venture further out into the solar system.  

Risk is a part of all of our lives, and it’s scary. But very few rewards come without risk. I chose to pursue this mission as a postdoc at ASU. It’s not common to give a moon mission to someone who is essentially fresh out from completing their PhD. But despite the risks, I put everything I had into it — I devoted many months to pulling together our team and working on the proposal. And our team, despite the risks, put everything they had into it too. I’ll be honest, we all knew the chances of success were low. And the risk of failing was high, but the reward was even higher. And that’s what kept, and keeps, us going. That sounds familiar, high risk – high reward. The concept of these tiny spacecraft is something I believe in, it represents a vision of a future world that I want to live in, where space is more accessible than ever, to many more people than ever before, and I know many others share that vision too. And that makes the risk of working on LunaH-Map worth it. I wouldn’t have done anything else. And the best part is that I get to lead this visionary team of people and work with colleagues every day who believe in it too.


Craig Hardgrove leads the LunaH-Map mission, one of the ASU NewSpace projects. ASU NewSpace is partially supported by Arizona’s Technology and Research Initiative Fund. TRIF investment has enabled hands-on training for tens of thousands of students across Arizona’s universities, thousands of scientific discoveries and patented technologies, and hundreds of new start-up companies. Publicly supported through voter approval, TRIF is an essential resource for growing Arizona’s economy and providing opportunities for Arizona residents to work, learn and thrive.