How would electric arc propulsion work?
Amelia Greig, Ph.D.: The arc mining concept was actually based in part on the Pulsed Plasma Thruster technology that has been in use since the 1960’s for spacecraft propulsion. The arc is created across the surface of a solid inert propellant material such as Teflon. The ablated Teflon comes off as charged particles that can then be accelerated away from the spacecraft using electromagnetism effects to produce thrust.
Would solar panels give enough energy?
Greig: If the vehicle was operating on a sunlit part of the Moon’s surface then solar panels would most likely be able to give enough energy. However, if water was something that was to be mined this would be happening in permanently shadowed regions of the moon — which means they never receive sunlight — and solar panels would not work. In this case the design would need to switch to an alternate power source such as RTG [radioisotope thermoelectric generator] or beamed energy.
How did you mine the moon and why? Why do you need to mine the moon?
Greig: There’s a few reasons why we might want to mine the moon. First of all the Earth is very big, so when we have to try to get things off the surface of the Earth it requires these huge rockets you may have seen, and it is very expensive. If we are trying to build up human capabilities to live and work in space it is much more effective for us to find the resources at the location where we are going rather than trying to take everything with us.
If we (humans) were able to colonize space and use space resources in manufacturing then we can move mining and manufacturing processes off the earth, creating less impact on the environment and reducing the demand on the limited Earth resources and energy supply.
Additionally, there are many manufacturing processes that would result in a better product if they were manufactured in space where there is microgravity. A great example of this is fiber optics and other similar glass products, which would result in significantly improved internet and networking capabilities on the surface of the Earth.
How long would [the ablative robot] last?
Greig: We are still in the early stages of the research and development for the ablative arc mining concept so this is not something we have looked extensively at yet. We would aim to have at least three to five years of operation to start with.
Will you be able to test out this technology in the polar regions of Earth?
Ethan Schaler, Ph.D.: Absolutely! We’ve chatted with a number of scientists who would love to deploy SWIM robots under glaciers or ice sheets, as well as in other interesting underwater locations like deep hyper-saline anoxic basins (DHABs). Before we can do that though, we need to build and test a number of prototypes, which we’ll be starting to do in our Phase II NIAC.
Science fiction has suggested that exploration of worlds like Europa could be harmful to any nascent life there. What steps do you take to ensure that your robots don’t interfere with early evolution?
Schaler: This is an incredibly tough problem to solve, and I think that there are actually two real issues to deal with:
- We don’t want to affect or harm any life already on an ocean world.
- We don’t want to bring any life with us from Earth that could accidentally contaminate or colonize an ocean world.
Regarding issue one, it’s difficult to explore without interacting with the environment in some manner, but by using miniature robots for SWIM, we do hope to limit our impact. For example, our robots have a very limited power supply, which reduces the chances they can act as a long-term source of energy or heat, and they don’t generate significant plumes of thrust.
Regarding issue two, we’re planning to work with planetary protection experts at JPL [NASA's Jet Propulsion Laboratory] to understand what design choices, material selection and cleaning steps can minimize the chances that we’ll bring Earth life with us to an ocean world. There are a whole combination of actions we can take, such as building the robots in a clean-room and then baking the robots in an oven for many hours.
What signifies a world that merits exploration? How will you choose your targets for these robots?
Schaler: To a large extent, we rely on the expertise of scientists to identify worlds of merit for us and what types of physical or chemical measurements we need to take to identify habitable environments (or discover signs of life). There are also extensive studies that are generated for NASA’s Decadal Surveys, which plan out important science goals for the next 10 years, worlds to visit and what specifically to explore. In our case, we look for worlds with some form of liquid (ideally water, although there are methane lakes on Titan that might also be interesting) and an energy or chemical gradient (which is needed to permit life as we know it to exist and grow).
Specific targets will be more challenging to identify, but we’ll likely rely on a variety of measurements to understand the physical (temperature, pressure, etc.) and chemical (salinity, redox potential, etc.) properties of the ocean near the ice-ocean interface and then look for abnormal signals within those measurements and swim to find where those abnormal signals come from. We may also look for “biomarkers” of interest — chemical compounds that likely wouldn’t exist without being produced by life as we know it. For example, on Earth you might look for chlorophyll in the water since it’s produced by algae, but we need additional guidance from scientists as to what might exist on an ocean world.
Would deployment of SWIM be included in a larger exploratory mission to an ocean world? Or is it designed to stand alone?
Schaler: SWIM is designed to be included in a larger exploratory mission, since our robots are only designed to explore an ocean (not drill through the tens of kilometers of ice to get there). There are also other NIAC ideas like the Enceladus Vent Explorer (EVE) that would involve robots crawling directly down vents/fissures in the icy crust to access the ocean.
What advice would you give to a young person who wants to work with NASA someday?
Schaler: There are so many ways to get involved with NASA, and I work regularly with people that have science, engineering, art, manufacturing, business and law backgrounds, and we’re all brought together through our shared interest in space exploration and the work NASA does. No matter what you study or are interested in, there are ways to follow those interests to NASA. For example, artists at JPL help me create pictures of my robot concepts to better communicate my ideas to others, contract managers with business backgrounds help me create budgets for my projects and lawyers help me patent new ideas and designs that we generate.
Looking at my own path to NASA/JPL as an engineer, I’ll just add that having a good foundation in STEM subjects — math, science, engineering, etc. — is quite important. There are also opportunities to intern at a NASA center (mostly in college), scholarships that NASA provides (mostly for graduate school) and often professors at universities that already work with NASA on research projects. I’ll end by just saying that everyone who comes to NASA (myself included) has a huge amount of information they learn on the job, so it’s normal to apply for an internship or job even if you’re not already a rocket scientist!
Greig: Anyone can work for NASA so go for it! If this is something you think you might want to do in the future then it is never too early to start building skills you might need. I don't mean just technical skills either, things like teamwork and leadership are vital skills to have. These can come from a huge variety of places, such as sports teams, youth clubs, performing arts troupes and so on. Also in my experiences, knowing people and having connections will always help. You don't have to be born with them — as a first generation immigrant I certainly wasn't — but you can make them easily by attending events and talking to people you don't know. You never know who you are going to meet and what opportunities might come out of it!
Katherine Reilly: If a young person is seriously interested in possibly working at NASA one day, they should contact the NASA Internship Office within the Office of STEM Engagement. They offer a variety of exciting jobs for students in high school and college across the country in many different scientific, technical and other disciplines. There are also “Pathways Interns” who are awarded paid internships that are direct pipelines to employment. It’s never been a more exciting time to be an intern at NASA!
How do you overcome failure when testing your projects?
Greig: Failure is one of the most important parts of testing, especially in early stage research and development. You can learn a lot more about a system when it fails than when it works. Pushing a system to failure identifies the points in the systems that are not yet well understood, or that need more design work (and why). So I would say failure is not something to be overcome, but something that is an integral part of the process that should be embraced!
Schaler: For the “iterative design” projects I work on, our entire workflow is focused on building a prototype, testing it early and often, identifying what breaks or doesn’t work right, understanding why that happens, fixing the issue, and testing some more. It can be incredibly frustrating when something you’ve worked hard on doesn’t work right the first, second or tenth time, but focus on what you’ve learned and eventually things start to succeed.
Reilly: In research, failure is very common, especially if you’re breaking barriers and expanding technologies to new horizons, which our Fellows do so well. It’s an essential part of technology development and is considered more of an “aha moment” versus something bad. Failure is perceived as a pivot point or a redirect that needs to be taken in order to get to the next level of advancement. The number one key to dealing with failure: learn from it, and persevere.