Discovery Space: Next Generation

Paving the Moon

A couple of years ago, I landed an internship at the Goddard Space Flight Center in Greenbelt, Md. with a mission: to help finish the design, construction and testing of a prototype "dust mitigation vehicle".

I couldn't wait to get started, but I had a few questions -- what exactly is a "dust mitigation vehicle," and why would we need one?

The "why" is pretty surprising. During the Apollo program, lunar dust (or "regolith" as the geologists like to call it) proved to be a significant challenge. Apollo 17 astronaut Gene Cernan even went as far as to say, "I think dust is probably one of our greatest inhibitors to a nominal operation on the moon. I think we can overcome other physiological or physical or mechanical problems except dust."

The fine-grained particles wore through the outer layer of astronauts' spacesuits, caused seals to leak, scratched visors and even affected astronauts' health with breathing issues. Whenever the regolith so much as touched a piece of equipment, astronauts found it nearly impossible to clean.

Those are a just a few reasons why lunar dust is so problematic.

As Ryan mentioned in his September 25th blog entry, it is extremely abrasive, meaning that it is able to scratch most things with which it comes into contact. I suppose I'd compare it to ground-up shards of glass. To make matters worse, the dust is statically charged. If you've ever rubbed a balloon on your head, you can wave the balloon over pepper grains to make them cling to it. Same concept with moon dust, except that instead of pepper the astronaut attracts microscopic, razor-sharp particles.

No surprise, then, that NASA spends a lot of time and resources to find ways to both prevent dust from getting on equipment and to remove it if necessary.

The Dust Mitigation Vehicle (or “DMV”) that I worked on is one of these methods. It's a prototype of a rover that would pave the surface of the Moon. It doesn't use asphalt or concrete, but rather sunlight -- something of which we have a nearly unlimited supply on the moon!

The DMV is essentially a rover with a giant converging lens mounted to it. Ever used a magnifying glass to burn leaves (or even poor, defenseless ants) during the summer? Again, same concept.

The vehicle's lens tightly focuses sunlight on area ahead of the vehicle, causing the regolith to reach temperatures well above 3,000 degrees Fahrenheit -- this heat melts the moon dust into a hard, dust-free surface. Run the DMV long enough, and you can create roads or even landing pads. When astronauts or other rovers travel on these hardened areas, they would no longer kick up dust.

I hope that some day vehicles similar to the DMV traverse the surface of the Moon and build roads as they go. If that doesn’t happen, I suppose I could open my own chemical-free ant extermination business. Either way, working on this project has been personally rewarding -- and a lot of fun.

Brandon Hall is an aerospace engineering undergraduate student at the University of Maryland, College Park. He has conducted research with NASA Goddard Space Flight Center focused primarily on In-Situ Resource Utilization.

Photos: Courtesy of Brandon Hall/NASA

Captions, top to bottom:

• Overseeing DMV operation. I'm using welding goggles to protect my eyes from the intense focused sunlight.
• The Dust Mitigation Vehicle with the large Fresnel lens clearly displayed
• Partially and fully “paved” samples.
• A profile shot of the DMV.

Strike a Pose, Gravity

What's the deal with gravity?

We don't know what causes it, but we do know it's a force that occurs when two objects -- such as the Earth and the moon -- attract to one another. We also know that if each object is treated as a perfect sphere, the math describing gravity is fairly simple.

But reality bites, and the Earth is not a perfect sphere. It has deep oceans and towering mountain peaks, and is thicker around the equator. Each little rock, pebble, grain of sand and molecule of water pulls on the moon, planets, the sun and everything else in the universe. Needless to say, accounting for these disturbances is a difficult problem.

Since before the first satellite launch, humanity has studied gravity anomalies, and those investigations have brought us to the Gravity Recovery and Climatology Experiment, aka "GRACE," which uses special satellites to measure this mysterious force.

See right for a 3-D map of these anomalies that the GRACE mission has teased out. The red indicates anomalies stronger than Earth's average pull of gravity (about 32.1740486 ft/s²), while the blue shows weaker-than-average anomalies.

Looks cool, but what do we do with this kind of information?

From modeling satellite orbits to monitoring the melting of glaciers and the polar ice caps, the benefits are numerous. To elaborate on the glacier example: If one is melting, the water drains away. That change in water means a change in mass -- and that translates to a small change in gravity around the glacier. So we can use gravity to study climate change.

Here's where I fit in: Scientists and engineers have used one type of gravity model for the past 100 years -- it's called spherical harmonics and is a bit dense to describe here (just look at the equation). My research looks at gravity from a totally different perspective, and to understand it, let's talk photography.

A photograph helps us preserve a memory, e.g. you as a kid. Years later, the picture reminds us of what we looked like when we were younger. That retrospective approach is similar to the gravity modeling I'm studying: Let's take our knowledge of the Earth's gravity, and store that information like a photograph so we can use it later. And instead of taking a picture of what the Earth visually looks like, we take a snapshot of what the Earth gravitationally looks like.

But one photograph doesn't show us the whole picture. If we take a picture of one side of the Earth, what does the other side look like? How do we know what gravity is like there? Even two pictures don't lend us a clear picture of the edges. We actually need six photographs to give us the Earth as a cube (see right).

So, why this new way versus the "old" way?

We've all sat there, waiting for a computer game or some piece of software to run... the more complex it is, the longer it takes for the computer to crunch the numbers. The "cubed sphere" model of gravity actually makes the software scientists use run faster -- so you get the speed of a rough test with the accuracy of an incredibly complex one. For people trying to model how their shiny new satellites will react to the Earth's anomalies while in orbit, that's a valuable improvement.

Modeling gravity is especially important for missions to the moon, since the spacecraft will be carrying people, and the moon's gravity is much more irregular than the Earth's. Better mapping of the moon's gravity not only improves simulations for planning trips there, but also helps astronauts figure out precisely where their spaceship is without asking for help from Earth.

It's also useful because, quite simply, someone can easily zoom in on a region they're interested in. Like looking at pictures of ourselves from when we were younger, we can use this cube-like model to easily see changes over time in things such as melting glaciers, mountains and more.

Brandon Jones is PhD student in aerospace engineering at the University of Colorado, Boulder.

Photos, top to bottom: Brandon Jones; NASA. Wikimedia Commons; Brandon Jones

Helping NASA Get a Raise

This May I went to Congress to help NASA get a raise. Perhaps surprisingly, I don't work for the space agency -- and I'm a student.

I've always supported NASA, but had never really made a good list of reasons why. That's when I joined the Citizens for Space Exploration -- a group of small and large businesses, teachers, students, local government employees, and others who believe investing is space exploration is a great idea.

Over the course of four days, 146 people from 29 states visited hundreds of congressional offices to make the case for NASA (my group met with North Carolina and Maryland representatives). When I first heard about their trip to speak with members of Congress, I expected everyone to be part of the space industry. I was wrong. No one in my group of five "citizen taxpayers" had ever worked for NASA.

Our meetings with representatives lasted anywhere from 15 to 45 minutes, during which time we explained the importance of NASA in the future of America and asked for a boost in the space agency's funding. How much, and by when? From 0.6 percent to 1 percent of the national budget by 2013. To get some perspective, look at NASA's funding during the Apollo era -- it received 4 percent of the national budget (almost seven times larger than today's funding situation).

I went on the trip because I've come to understand that NASA validates our role as explorers, has far-reaching educational benefits and creates new technology that ultimately brings us so many things we take for granted. By the end of my congressional visits, I felt like I could convince a total stranger why they should care about NASA.

We are an exploring species. Every elementary school student can tell you about Christopher Columbus' voyage, but few can tell you how the Norsemen found America in 1000 AD -- Columbus simply opened the floodgates to settling the Americas.

Like pre-Columbian explorers, we have visited the moon and now plan to settle it. NASA needs the proper funding to work towards permanent lunar colonies, but is a bit strapped. Imagine if Europeans had decided that it was too expensive to travel across the oceans and settle unknown lands. Now compare that to what future the other planets might hold for us.

To return to and colonize the moon, we need to develop new technologies. For example, moon settlers need to be able to generate their own food supplies and air to breathe on the moon. In the process of researching how to do such things, we push the technological barrier.

For example, the imaging technology used in some telescopes is now used to help detect cancer. My father is an orthodontist and uses brace wires derived from morphing materials researched by NASA. My mother is a physical therapist and uses a machine developed through research conducted on astronauts after they returned to Earth.

Maybe more important than technology spin-offs are the "people spin-offs." Teachers try to inspire students because they know it will help drive them to learn and succeed. A child who wants to be an astronaut knows they have to stay in school, stay out of trouble, attend college, etc. Although he or she may not become an astronaut, they're like to be inspired to go to college and stake out a career in science, technology, engineering, or math.

As a member of this new generation of explorers, I'm thrilled to help NASA return to the moon and colonize it, then head to Mars -- and beyond.

Laura Meyer is a University of Maryland senior in aerospace engineering at the James A. Clark School of Engineering.

Designing NASA's New Moon Crib

I never expected to find myself working on a project with NASA, mainly because I wasn't particularly gifted in math or science. The most I remember from high school chemistry class was the teacher shouting, "That was spontaneous!" every time he caught us rolling wooden molecules across the linoleum floor.

Now, as an industrial design student heading into a second year of grad school at the Rhode Island School of Design, NASA is exactly who I'm working with. 

The connection bewteen RISD and NASA started with Michael Lye, my dedicated professor, throughout a decade of coursework that brought the two institutions together. Thing is, design school can be short on real-world constraints, often drifting into conceptual and theoretical regions, while NASA has no shortage of constraints.

It was a wonderful match.

I was hired along with four other students for a summer to work on NASA's new lunar lander suitlock/airlock project for the lunar habitat -- a setup the agency plans to use for extended stays on the moon. The major challenge facing astronauts once they arrive? Moon dust.

Inside an astronaut's living space, moon dust can be a big hazard by causing allergic reactions and grinding away at small parts in equipment. So NASA asked for a habitat that could keep lunar dust out.

Other factors we had to consider included strong, protective storage places outside of the living quarters and space suits tough enough to handle the moon's unforgiving conditions. Also, the astronauts needed to be comfortable in their spacesuits, able to reach the suit storage containers, and go into and out of the habitat safely and easily.

With Michael at our side, we took a first crack at the habitat and improved NASA's "Mark III" space suit design. It was essentially a clean slate: Help astronauts get into new one-piece-style suit, get out of the habitat, then get back safely. The rest was up to us.

After weeks of conference calls with the Human Factors team in Houston, we quickly found our tasks snowballing, and were proposing designs for dozens of things: the hinging mechanisms on the door, way-finding signals, foot and hand supports, bulkhead formations, airlock space, and on and on. The complexity of each spacey challenge quickly became apparent to us as we worked.

Our mission, however, wasn't all work and no play. A particularly fun phase came when we built a one-sixth gravity harness in our studio, then put the suit through a number of physical tests to see if it would hold up in true moon-like conditions. (Also check out the video at the end of this post.)

In mechanical engineering humans needs often come last, but we had to put the body first. We started by comparing the body with the original Mark III design. Unfortunately, the prototype is a multi-million dollar piece of equipment, so we couldn't physically get our hands on one. Instead, we spent weeks researching and talking to the makers, then constructed our own rendition of the suit -- keeping in mind the capabilities and limitations it put on the wearer, of course.

For example, could he or she see over her shoulder?  (Nope.) Asking such simple questions created a domino effect of design needs: When astronauts bend their knees in the suit, at what angle of knee bend did the suit and body weight become too great to push up to standing position? And so on.

Unlike countries that put restrictions on their spaceflyer height, American astronauts are a wide range of heights -- so the suitlock and airlock needed to be adjustable (yet another aspect we had to take into consideration). And after studying a set of gorgeous, custom-built astronaut gloves, we got a sense of how limited astronaut dexterity and mobility would be. That's a big deal, because we knew the astronauts would need to use small pieces of hardware. 

By starting with the design approach, I think we were able to innovate in ways we might not have if we began with a focus on engineering. In the long run, I hope our work creates a more comfortable (and productive) experience for astronauts visiting the moon.

Julianne Gauron is a second-year industrial design student at the Rhode Island School of Design. For more information about the RISD NASA collaboration see, click here.