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BLAIR: Welcome… to be honest with you, I can’t tell you where we are. They won’t tell me. For some strange reason they don’t trust me. So we’ll just have to say we’re at an undisclosed location at NASA Kennedy Space Center. We were going to interview Tracy Gill, Deputy Project Manager for the Habitat Demonstration Unit. Due to circumstances beyond our control, we couldn’t conduct that interview. Tracy, however, came through big and delivered interviews with Dr. Carlos Calle of what I like to call the magic space dust removal program. And Dr. Ray Wheeler, who is a plant biologist who is learning all the great things you can do with plants in space. I’m going to try to find out exactly where we are.
BLAIR: We’re here with Dr. Carlos Calle. We’re talking about the dust mitigation system. I worked with your teammates out at Desert RATS where they explained the dust mitigation system but apparently there’s a lot more to this system that I didn’t know. Explain to me what you do here.
DR. CALLE: We’ve been working with this technology for seven years now. We started to develop a way to remove dust from solar panels on Mars. Mars, being a dusty planet, has a big problem with dust accumulating on solar panels. So, that was our first approach to this technology. Let me show you.
BLAIR: Yeah. What are some examples?
DR. CALLE: Some examples, yeah. The one we tested at Desert RATS, we have two panels here.
DR. CALLE: …to demonstrate that we could remove dust from the windows that we attached to the door, as you remember.
BLAIR: Right. Exactly.
DR. CALLE: To demonstrate that we could maintain the hatch clean so when the Rovers mate with the Habitat, before the doors are open you need to clean these things.
DR. CALLE: …so we don’t have dust in the Habitat. This particular type of panel contains two sets of electrodes, which are like sets of fingers interlaced. We apply a signal which is out of phase. So, we apply the signal to this electrode and then to that one and back to this and then to this. A one, two, one, two, one, two.
BLAIR: The reason you do that is if you sent the signal once it would lift the dust but the dust would settle.
DR. CALLE: Back.
BLAIR: …right back down.
DR. CALLE: Right back down. Exactly. So this is the way to make it “walk.”
BLAIR: I really expected this to be more like a “Little Shop of Horrors.” And there’s no dirt here. I was wondering what do you actually do in the lab with plants?
DR. WHEELER: In this case, we’re doing preliminary setups of some plant growth approaches that we think might work in space, like on the International Space Station. Then we’ll do follow-up tests in controlled environment chambers. Larger chambers where we can set the plants out and control the temperature and the light intensity. If you think about space, you have certain constraints. You have to contain water for example. How do you water a plant in weightlessness? It’s not a trivial issue. So you have to be able to contain that and come up with techniques to provide water to the roots.
BLAIR: I noticed earlier you were changing the color of the light.
DR. WHEELER: In this case, we’re using LEDs, light-emitting diodes. As you know light-emitting diodes, LEDs, usually have very discreet colors. That is just intrinsic to their nature. We have used combinations of them to make different spectral composition comparisons.
BLAIR: You, actually, can grow a plant with only one color, Red?
DR. WHEELER: Yes. You can. Red light is a good light source for photosynthesis. Chlorophyll absorbs it. So it drives the photosynthetic reactions but if you use red light only, the plants tend to be leggy and stretched out.
BLAIR: Leggy? [chuckling] I’ve never heard of a plant referred to as leggy.[whistle]
DR. WHEELER: But if you add some blue light, they behave much more normally in terms of their morphology. They stay more compact and normal looking. Another thing is you need blue light to orient the plants toward the direction of light. That’s important in space because you don’t have a gravitational clue anymore for the plants to grow against the gravity. So you have to orient them with light. And you need blue light to do that.
DR. CALLE: This is one that we developed to protect optical systems, camera lenses and so on.
BLAIR: Is this just a glass?
DR. CALLE: It’s a piece of glass but it has…
DR. CALLE: …transparent electrodes, which have a different configuration. We have three of those. In this particular case, when we wrap them around in a circle like that then we have an electric field that radiates out.
BLAIR: Got ya.
DR. CALLE: It’s like ripples on a pond.
BLAIR: Right. Otherwise, you could create pockets where the dust wouldn’t move.
DR. CALLE: Right.
BLAIR: So you have to work that way.
DR. CALLE: So, you can have the same panel that I showed you earlier down here in this box.
BLAIR: Oh. You have an example.
DR. CALLE: We have a brush we use to deliver the dust to simulate exploration activities on the moon that would kick up dust. I’m adding actually a lot of dust.
BLAIR: You are adding a lot of dust. I’m feeling uncomfortable, like you’re besmirching the test article. Have you ever added too much and been unsuccessful with your test?
DR. CALLE: Actually, yes.[Blair laughing]
DR. CALLE: If you pile it up. Actually, it works eventually.
BLAIR: Over time? It takes a little longer. You’re going to just throw a switch?
DR. CALLE: I’m going to throw a switch and activate the three electrodes.
BLAIR: Oh wow! Oh wow!
DR. CALLE: So it’s very free where the electrode system is.
BLAIR: It looks computer generated.
DR. CALLE: Right.
BLAIR: Oddly, it seems to work inward. So there’s not a lot of carryover. Once they get away from the electrodes.
DR. CALLE: That’s it.
BLAIR: …dust settles again.
DR. CALLE: Yeah.
BLAIR: What would happen if you dropped dust now?
DR. CALLE: We can do that.
DR. CALLE: We can do that.
BLAIR: Are you sure?
DR. CALLE: We keep it running and we can drop dust on it. We’ll see what happens. It actually deflects it.
BLAIR: Yeah, it won’t stay on.
DR. CALLE: It’s a shield. Even if you dump large amounts of it, it just deflects it.
BLAIR: Why do you need to do more testing? This looks 100% successful in my untrained eye.
DR. CALLE: It is very successful but it is a small scale still.
DR. CALLE: For Desert RATS, we scaled it up for this configuration, an 8x10, and a 9-inch diameter circular panel for the window. This year we’re going to try to see if we can cover the entire hatch, which is about a 2 ½ x 4-foot door.
DR. WHEELER: One of the factors we are trying to incorporate into our testing and our strategies is to choose plants that are high in antioxidants. Those are compounds that can repair damage in your cell tissue, your DNA. If there’s radiation damage, for example, can we add fresh foods to the diet that could serve as the radiation counter measure? It’s a high-radiation environment. So the astronauts are exposed to this. Can we augment the diet with something that would give them a measure of protection in living in that environment? As the missions go farther, and stay longer, then, of course, if you can begin to expand these systems, now you can generate oxygen. You can remove and reduce the carbon dioxide. And you could couple wastewater treatment systems with these plants as well. You could do multiple life support functions as you begin to scale these up.
BLAIR: It’s funny. As important as I think plants are to the aesthetics of living, it seems there are lots of ways that strategically they can be used to help the astronauts.
DR. WHEELER: All the oxygen we’re breathing right now on the surface of the earth was generated through photosynthesis.
BLAIR: If we play our cards right, maybe we’ll create an atmosphere on Mars.
DR. WHEELER: Maybe. Maybe the day will come.
BLAIR: Then maybe I can move there. I’m sure a lot of people would be happy about that.[clapping]
BLAIR: One other rumor. And you can either confirm or deny if this is true. One thought is you’d like to incorporate this technology even within clothing, i.e. a spacesuit.
DR. CALLE: Right.
BLAIR: Is that true?
DR. CALLE: Yeah. We have done some work.
BLAIR: Oh yeah, it’s very flexible.
DR. CALLE: It’s actually a piece of cotton. The electrodes are made of carbon nanotubing that was actually developed in our Polymers Lab here at KSC.
DR. CALLE: We tested these in air and a vacuum successfully.
DR. CALLE: The next step, of course, is to go from cotton to a more representative material for spacesuits, and that is the challenge.
BLAIR: If this technology works, maybe they can reconsider cotton Dockers up there in space. A hundred percent cotton Dockers. As a matter of fact, I’d like a pair of cotton Dockers…
DR. CALLE: There we go.
BLAIR: … with this on them. I’d be really hip and dust free. Very good. Thanks so much for your time.
DR. CALLE: My pleasure.
BLAIR: You’re watching NASA EDGE, an inside and outside look at all things NASA, completely dust free.
DR. CALLE: There you go.
BLAIR: Thank you very much. I appreciate it.
DR. CALLE: You are very welcome.
BLAIR: This is awesome. I can’t believe you can keep the dust off there perpetually. It’s great!