Who's Who at NASA

Dr. Drake Deming, Senior Scientist, Solar System Exploration Division, Goddard Space Flight Center

Dr. Drake Deming, former Chief of Goddard Space Flight Center’s Planetary Systems Laboratory, currently serves as Senior Scientist with NASA’s Solar System Exploration Division where he specializes in detecting and characterizing hot Jupiter extrasolar planets. Dr. Deming was named recipient of the 2007 John C. Lindsay Memorial Award, Goddard’s highest honor for outstanding contributions in space science, for his work in developing a way to detect light from extrasolar planets and use it to measure their temperatures. NASA Tech Briefs: What is the Solar System Exploration Division’s primary mission within NASA and what types of projects does it typically handle? Drake Deming: Our primary mission is to study planetary science in the context of NASA’s space mission program. In this case planetary science also includes planets orbiting other stars. NTB: You began your career in education teaching astronomy at the University of Maryland. What lured you away from academia to pursue a career with NASA? Deming: Research, and the opportunity to do cutting-edge space-based research. NTB: Had you always planned to move in that direction, or was it after you had started your career that NASA entered the picture? Deming: I had always planned to move into research. NTB: Much of your research over the years has focused on trying to detect and characterize so-called “hot Jupiter” extrasolar planets. What are “hot Jupiter planets, and what can we learn from them? Deming: Hot Jupiters are giant planets, like Jupiter in our own solar system, but they’re in much closer to their stars. Not only are they much closer than Jupiter in our solar system is, but they’re much closer even than our own Earth. What we can learn from them is quite a bit, because they’re in so close to the star they’re subject to strong irradiation from the star, so the dynamics of their atmosphere is very lively, the circulations are very strong, so we can learn about the physics of their atmospheres. Also, they are subject to tremendous forces from the star; they’re subject to tidal forces, which may play a role in inflating their sizes. So, we can learn about their internal structure, and we can learn a lot about planets from studying hot Jupiters because they’re an extreme case. NTB: Why are extrasolar planets so hard to detect? Deming: They’re so hard to detect because, so far, we cannot spatially resolve them from their parent stars, so we have to study them in the combined light of the planet and the star. That means it’s a small signal riding on top of a large noise source – in this case, the star. NTB: You are the principal investigator on a program called EPOCh, which stands for Extrasolar Planet Observations and Characterization. Tell us about that program and what you hop to accomplish with it. Deming: Well, we have just concluded our observing with EPOCh. We have over 170,000 images of planet-hosting stars, and when we get these images we don’t resolve the planet from the star. We use the images to do precise photometry. These are bright stars that have planets that transit in front of them, and the geometry of the transit tells us quite a bit about the planet. It tells us the radius. We can examine the data to see whether it has rings or moons. We can look for other, smaller planets in the system that may transit. And in favorable cases our sensitivity extends down to planets the size of the Earth, so we’re searching for smaller worlds in these systems. NTB: You’re also the Deputy Principal Investigator for a mission called EPOXI…Deming: Yes. That’s the same as EPOCh. EPOXI is a combination of EPOCh and DIXI (Deep Impact eXtended Investigation). DIXI is the component of EPOXI that goes to Comet Hartley 2, and that’s now ramping up because EPOCh is finished. NTB: What is that mission designed to accomplish? Deming: Well, I’m not involved in that, but it’s designed to image a comet nucleus. It will use the imaging capability of the Deep Impact flyby spacecraft to image another comet. The original Deep Impact mission released an impactor into a comet nucleus and actually blew a crater in it. Of course, the impactor is no longer available to us because it was used up, but still, a tremendous amount can be learned by imaging another comet nucleus for comparative purposes. NTB: That was the Temple 1 comet, right? Deming: That was the Temple 1 comet. NTB: EPOXI spent most of the month of May observing a red dwarf star called GJ436 that is located just 32 light years from Earth, and it has a Neptune-size planet orbiting it. What did you learn from those observations? Deming: We’re still very intensely analyzing those data, but what we hope to learn is whether there’s another planet in the system, and in this case our sensitivity extends down to Earth-sized planets, so we’re looking for another planet that may have left a small signature in the data as it transited the star. If we can find that, there’s a good chance that that planet might even be habitable. Because our period of observation extends for more than 20 days, and because this is a low-luminosity red dwarf star, the habitable zone in that system is in close to the star where the orbital periods are on the order of 20 days. So we have sensitivity to planets in the habitable zone in this case. Of course, those data have our highest priority and we’re inspecting them very intensely. However, the data analysis process is very involved. We have a lot of sources of spacecraft noise that we have to discriminate against. NTB: In July 2008, NASA’s Deep Impact spacecraft made a video of the Moon transiting – or passing in front of – the Earth from 31 million miles away. Why did that video generate so much excitement within the scientific community? Deming: Well, I think it generated a lot of excitement both in the scientific community and outside of the scientific community because it’s really, I think, the first time that we’ve seen the Earth/Moon system from that particular perspective, from that specific perspective, where you see the Moon transit in front of the Earth. And there’s also, as we analyze those data, some realization that although it would be a relatively low probability that, if that were to occur for a planet orbiting another star and its moon transited in front of it, we could learn about the topography of the planet. NTB: Do you think we’ll learn anything new about Earth from that video? Deming: I think we’ll learn new things about the Earth as a global object, as an astronomical object. For example, one of the things we should start prominently seeing in the data is the sun glint from the Earth’s oceans, and this has been hypothesized as a way to detect oceans on planets orbiting other stars because that glint would be polarized. Although we don’t have any polarization capability, we can see that the glint sometimes becomes dramatically brighter and we’re trying to understand why that is. It may be because the glint is a specular reflection, probably from the Earth’s oceans, so by correlating that glint, the brightening of that glint with, for example, winds across the oceans and wave heights, we may find that smooth patches of ocean give us a particularly strong glint. So, if the glint were observed on an extrasolar planet, we could then infer from a variable polarization signal the presence of the glint and the presence of oceans. NTB: It was discovered some time ago that Deep Impact’s high-resolution camera has a flaw in it that prevents it from focusing properly. This was a problem during its original mission when it was trying to study a crater made by an impactor on the comet Temple 1, but you were somehow able to use that to your advantage to study planets passing in front of their parent stars. Can you explain how that works?Deming: That’s a big advantage for us because we’re not trying to image the planet. We’re only measuring the total photometric signal, so when the planet passes in front of the star we see a dip in intensity. That dip in intensity is, like, one percent. We’re doing very precise photometry, so that one-percent dip is actually the largest signal we see. We’re actually looking for much smaller dips due to smaller planets. Well, in order to measure that dip very precisely, we have to get a very precise photometric measurement, which means we need to collect a lot of light from the star. If we didn’t have the defocus, all of that light would be falling on one or two small pixels of the detector and they would immediately saturate. We’d have to constantly be reading them out and it just wouldn’t be practical. But by having a defocused image, we can spread the light over many pixels and use them to collect more light in a given readout. For each readout we collect many more photons from the stars. NTB: Among your many accomplishments at NASA, you developed a way to detect light from extrasolar planets and use that light to measure their temperature. Can you explain how that technique works? Deming: This was an observation with Spitzer. And it was also done concurrently by Professor David Charbonneau at Harvard. The Spitzer Observatory wasn’t really developed for that purpose. We just found that that it was particularly capable of that application, and what we did was we observed the systems that had transiting planets in the infrared where the planet is a significant source of radiation and we waited until the planet passed behind the star – and we could calculate when that would be – and then we saw a dip in the total radiation of the system. Since we knew the planet was passing behind the star at that time, the magnitude of that dip tells us the magnitude of the light from that planet. So, in that way we were able to measure the light from extrasolar planets. This has become a big topic of research for Spitzer. Spitzer has done this for many planets over many wavelength bands. It has been able to reconstruct, in kind of a crude way – but even crude measurements of planets orbiting other stars are very revealing and important – it’s been able to reconstruct the emission spectrum of some of these worlds orbiting other stars. NTB: In 2007 you won the John C. Lindsay Memorial Award, Goddard’s highest honor for outstanding contributions in space science. What does it mean to you to have your name added to such a distinguished list of scientists? Deming: Well, of course, I was very honored to receive this award. I was also very surprised because I had no indication, no hint, that this was coming. NTB: Nobody tipped you off? Deming: Nobody tipped me off. It was a complete surprise. I think the award speaks not to my own personal accomplishment but to the success of the NASA missions that enabled the measurements and all the people who designed and built the Spitzer Observatory. It wouldn’t have been possible to make those measurements without that facility. For more information, contact Dr. Drake Deming at leo.d.deming@nasa.gov.  To download this interview as a podcast,

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Glenn Rakow, SpaceWire Development Lead, Goddard Space Flight Center

Glenn Rakow is the Development Lead for SpaceWire, a high-speed communications protocol for space-flight electronics originally developed in 1999 by the European Space Agency (ESA). Under Rakow’s leadership, the SpaceWire standard was developed into a network of nodes and routers interconnected through bi-directional, high-speed serial links, making the system more modular, flexible and reusable. In 2004 Rakow was named the recipient of Goddard’s James Kerley Award for his innovation and contributions to technology transfer.

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Dr. Woodrow Whitlow Jr., Director, John H. Glenn Research Center, Cleveland, OH

As Director of NASA’s John H. Glenn Research Center in Cleveland, Ohio, Dr. Woodrow Whitlow Jr. controls an annual budget of approximately $650 million and manages a labor force comprised of roughly 1,619 civil service employees who are supported by 1754 contractors working in more than 500 specialized research facilities.

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Garrett Reisman, Astronaut, NASA Johnson Space Center, Houston, TX

In March 2008, astronaut Garrett Reisman flew aboard the Space Shuttle Endeavour to the International Space Station, where he spent 95 days living and working in space. After performing his first spacewalk to help install the Space Station’s new robotic manipulator, called Dextre, he returned to Earth in June aboard the Space Shuttle Discovery. NASA Tech Briefs: You began your professional career at TRW as a spacecraft guidance navigation and control engineer. How did you go from there to becoming an astronaut? Did you approach NASA, or did they recruit you? Garrett Reisman: No, NASA doesn’t really do any recruiting. We have more people applying than we have spots available, so I definitely applied to them. It was something I always dreamed about doing, since I was a little kid, but I didn’t really get serious about applying or anything like that until I was almost finished with college and I realized that this was something that was within the realm of possibility. When I was in grad school at Cal Tech I put in my application, and there was a requirement for a couple of years of related work experience. So I thought, well, maybe a couple of years of being a graduate student would count for that. I sent in my application then and I didn’t get too far, but I got farther than I thought I would. I thought, NASA’s probably going to laugh at me for not having the field work requirements, but it worked out okay. The second time was when I was with TRW and that time I made it all the way through the application process, and through the interview, and I got selected. NTB: In June 2003 you participated in a two-week training exercise called NEEMO where you lived on the ocean floor 3.5 miles off the coast of Key Largo, Florida in an underwater laboratory called Aquarius. Describe for our readers what that experience was like and some of the challenges you faced. Reisman:That was amazing! That was one of the most remarkable things – probably the most remarkable thing – I got to do, up until I blasted off in the Space Shuttle. We moved down there for two weeks and we were going outside making scuba dives almost every day, and we had these giant windows in our habitat so we could see all the fish outside. It was a really healthy reef where we were, so it was remarkable how much sea life there was outside the window. It was very good preparation for spaceflight because we use the same types of tools and we do a lot of the experiments that we did down there. I ended up doing the same things up on the Space Station. The food was the same. We tried to make it as similar to flying in space as possible. I even had the same commander that I would later fly with as part of our mission, so it was great preparation and also a fantastic experience. NTB: You recently spent 95 days aboard the International Space Station, orbiting the Earth at a speed of 17,400 miles per hour. What is it like living in that environment?Reisman: It’s tremendous fun and probably, on a day-to-day basis, the most fun thing is being able to float. And you do float, but when you push off it’s more like flying. You kind of feel like a superhero. You can just jump off the floor, like Superman, and you keep going up and up and up until you hit something. It’s really a joy. Now, when I watch science-fiction movies and I see everybody walking around on spaceships, I wonder why they would deprive themselves of that joy of flying. NTB: How difficult is it adjusting to weightlessness over an extended period of time? Reisman: Over an extended period of time you get better and better at it. Initially you’re just flying about and you lose things and it can be kind of awkward. But over time you get much better at it. You get much more graceful with your motions and you get more efficient. You’re able to work more effectively and you just learn how to deal with it. Over time it actually gets better. NTB: What would you say are some of the more unique challenges faced by astronauts living aboard the Space Station, aside from broken toilets of course? Reisman: One of the things about working in zero gravity is you can’t put anything down. That’s really an issue. Just think about trying to work on your car, because when we’re doing maintenance work on the Space Station it’s kind of like working on a car. Every time you unscrew a bolt, you can’t just put it down; you have to put it into a zip lock bag, or tape it somewhere, or Velcro it to a wall. If you just let go of it, or you turn your back on it, it may be gone when you turn back around again and good luck finding it because it’s hard to find things up there. So that’s a unique challenge up there. It makes it very easy to lose stuff, and it takes a long time in the beginning until you get good at managing all the parts. NTB: As part of your mission aboard the Space Shuttle Endeavor, I understand you performed your first spacewalk. What was that like? Reisman: Well, it was the most extraordinary experience I had in the whole time I was there. At times I would describe it as a strange mix of the familiar and the outlandish. What I mean by that is, at times it felt just like training. We have this big pool here in Houston that we practice spacewalking in, and they do a great job of making it very realistic. So there were times I actually forgot that we were in space because it felt just like training. I’d be looking right in front of me at what I was doing, and it felt just like I was in the pool during one of our training exercises, and then you look over your shoulder and you see the entire east coast of the United States, and that is very different from training. So it was kind of a rollercoaster ride between things that felt normal and things that felt completely abnormal. NTB: A lot of people don’t realize that astronauts can’t simply don a spacesuit, exit the airlock, and go spacewalking. Preparations begin the night before with something called the “Campout Prebreathe Protocol” to prevent decompression sickness. Describe what that whole procedure entails.Reisman: You’re right in saying that you can’t just go right out the door because, just like in scuba diving, you have to be careful. There are certain maximum times you can spend at certain pressures, and with scuba diving if you come up to the surface too quickly, or after having stayed down for too long, you can get the bends. The same thing can happen to us. When we go outside it’s kind of like surfacing after a scuba dive, because you’re going from high pressure to low pressure, so to prepare for that you have to purge the nitrogen out of your bloodstream to make it safe. We kind of do it in stages. What we do is, we lock ourselves up in the airlock the night before and we reduce the pressure from 14.7 psi to 10.2 psi, and we stay at that overnight. As we do that, the nitrogen is slowly coming out of our blood. Then we get into our suits, and even before we put on the masks we breathe 100-percent oxygen. When we breathe 100-percent oxygen, we’re purging more and more nitrogen out of our blood. When you get in your suit, you’re breathing 100-percent oxygen in the suit, and when you finally get down to around 3 or 4 psi in the suit, you’re ready. At that point you’re not going to get the bends. NTB: One of the projects you worked on in space is a new Canadian-built robot called Dextre. Tell us about Dextre and what it’s designed to do. Reisman: Dextre is a really neat robot that is designed to do basically the same kind of things that we do during a spacewalk. It has two arms, and it has a body, and it can pivot about its waist, and it can grab a box of equipment outside of the Space Station. It can unbolt it; it can put it away; and it can take a new box to replace it and bolt that into place. Those are the kind of things it’s designed to do. It has its limitations as well, and we’re still working on exactly how we’re going to use it. I think in the future it’s going to be a very good helper. It will help make us more efficient during spacewalks and we might be able to to get the workspace set up before we get there. It can help us in that way. NTB: There were some problems assembling Dextre, namely some stuck bolts and a power feed problem that could’ve prevented the robot’s heaters from operating properly. How serious were those problems, and how did the crew overcome them? Reisman: Oh, they were very serious. First off, we had to figure out why it wasn’t getting power when we expected it to. Then we had to figure out how to work around that. The solution for the power problem was all worked out on the ground; we have some very smart people down here that figured out what to do. We just managed to use the other robot’s arm to attach to it and connect cables to it, and through that it was able to get power through the other robot. Of course, once it got power we didn’t know…it might have been dead. We didn’t know if it could’ve stayed healthy in that cold space without any power, but as it turned out it’s a true Canadian and it did just fine with the cold. When we got power to it, it worked just like it was supposed to. When you have problems like that and you find ways to work around them, and you’re ultimately successful, that’s one of the most fulfilling things that can happen to you as an astronaut. NTB: While in space you had the honor of throwing out a ceremonial first pitch for your beloved New York Yankees when they played the Boston Red Sox on April 16. On August 26 you again threw out the first pitch, this time in person at Yankee Stadium when the Bombers faced the Sox. Which pitch was the bigger thrill for you? Reisman: Well, I’ve got to say I was certainly a lot more nervous about being there, because it was easy to throw that pitch in space. I didn’t have to worry about bouncing it. It was pretty easy to throw a strike. But now, coming back down to Earth and dealing with gravity again, I was worried that my arm might not quite be in shape to throw a good strike. But being present at the stadium, in person, with all the fans, that was overwhelming. That was a dream come true for me. For more information, contact Katherine Trinidad, NASA Public Affairs at Katherine.trinidad@nasa.gov.To download this interview as a podcast,  

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Robert W. Moorehead, Director of Space Flight Systems, John H. Glenn Research Center

Robert W. Moorehead served as NASA’s chief investigator for the Space Shuttle Challenger accident in 1986 and managed the Space Station Freedom program from 1989 to 1993. He has also held the title of NASA’s Chief Engineer, developing system architectures for the Space Shuttle’s replacement. He is currently Director of Space Flight Systems at the John H. Glenn Research Center in Cleveland, Ohio.

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Dr. Jonathan Trent, Bioengineering Research Scientist, Ames Research Center

Dr. Jonathan Trent is an expert in the use of extremophile proteins to create nanoscale electronic devices. An extremophile is a life form capable of surviving in the harshest conditions on earth including severe heat, bitter cold, and extremely acidic or alkaline environments. The recipient of a 2006 Nano 50 Award as one of the leading innovators in the field of nanotechnology, Dr. Trent also leads the GREEN (Global Research into Energy and the Environment at NASA) Team at Ames Research Center.

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Dr. Anthony Colaprete, LCROSS Principal Investigator, Ames Research Center

LCROSS (Lunar Crater Observation and Sensing Satellite), which will travel to the moon aboard the launch vehicle for the Lunar Reconnaissance Orbiter (LRO), will test for the presence of water beneath the lunar surface by crashing a pair of heavy impactors into one of the permanently shadowed craters at the Moon’s South Pole. The impact will create a plume of debris that can be analyzed for the presence of water using specialized instruments. Dr. Anthony Colaprete, who is an expert on the Martian climate system, is principal investigator for the LCROSS mission.

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