Profile: Henry Helvajian, Senior Scientist, Micro/Nano Technology Department
Research That Leads to Innovation
For nearly 20 years, Henry Helvajian has been touting the virtues of using tiny components—or miniature satellites—to achieve big results in space.
“I have always been curious. I’ve never done the same dance step twice, which means I am always looking for ways to make things a little bit different, hopefully a little bit better,” said Henry Helvajian, senior scientist in The Aerospace Corporation’s Physical Sciences Laboratory. Helvajian develops new research areas, conducts experiments, mentors members of the technical staff and graduate students, and writes proposals to secure funding. He believes in the power of research and regrets that it is not given recognition in proportion to its use and importance. “People forget very quickly where the original ideas came from. Those original ideas—the things we do routinely here in the lab—came from somebody’s research. Somebody spent a lot of time getting an idea to work out.”
For example, Helvajian’s push to build and fly nanosatellites (spacecraft with mass between 1 and 10 kilograms) and to incorporate MEMS (microelectromechanical systems) took many years, even with the help of his research colleagues. He and other scientists in the lab first had to convince Aerospace management and then convince those with research funds to provide them for the necessary development. In the first five to eight years, they received a lot of pushback, “with jokes,” as they tried to convince anyone who would listen of the potentials of microengineering space systems. They presented their ideas many times to several government agencies, from the Air Force Office of Scientific Research (AFOSR) to DARPA (the Defense Advanced Research Projects Agency) to NASA. They started new conferences that would bring the MEMS research community together to focus on the aerospace industry, and they developed technology.
The persistence of Helvajian and his colleagues started to pay off in the 1990s, when Aerospace launched a box of MEMS experiments that flew on the space shuttle. “I remember pitching this idea to NASA, saying you need to look at making a small box that would fly inside the shuttle, with all these tests you can do. It wasn’t very complicated, and NASA bought it.” An Aerospace MEMS team put together 15 devices that flew and yielded phenomenal results. Tiny devices such as chemical sensors and accelerometers yielded data that compared with data from the shuttle’s own sensors. That was a big step. “How far all of this has come over the past 20 years! All the worldwide efforts in developing very small satellites, with major companies involved, with our traditional customers involved! Some of the success must be pointed to the phenomenal success MEMS has had in terrestrial applications. The microengineering of space systems is now inevitable because it offers intelligence, ‘volition,’ and motility to space systems on a miniature scale—and it has been shown to work. The remaining question is microengineering, yes, but to what extent?”
The amazing success of small satellites and their possible future applications was compellingly portrayed in Small Satellites: Past, Present, and Future, a book that Helvajian edited with his colleague, Siegfried Janson. “Small satellites started the Space Age, and applications for small and ultrasmall spacecraft will continue to expand to include a surprising array of missions—Earth observation, lunar and near-Earth exploration, interplanetary probes, and communications,” the authors wrote. More than 860 microsatellites, 680 nanosatellites, and 38 picosatellites had been launched at the time of the book’s publication in 2008. If all goes well, next year will be a boon in the launching of “CubeSats,” satellites measuring 10 × 10 × 10 centimeters and weighing a few kilograms. The CubeSat standard was proposed by Robert Twiggs of Stanford University after seeing the first Aerospace picosatellite (less than 1 kilogram) conduct a successful mission in space.
A Dual Focus
“For the past ten years,” Helvajian said, “my thoughts have been split between two different communities: microengineering space systems on the one hand, and laser material processing and photophysics on the other—two different areas I’ve been pushing.” Helvajian is looking at developing materials and processing techniques that will enable the construction of a spacecraft as an assembly of mass-producible functional modules.
More specifically, he is adapting biological systems architecture to satellite manufacturing. In biology, the cell is a self-organism with its own energy source. The cell replicates, and all biology has to do is make sure the cell replicates in the right way. Helvajian is trying to find out if anything remotely similar can be done with the way satellites are made: “You have a bunch of blocks, modules that are all the same. They have their own energy source, they communicate among themselves, they do not replicate but can be mass produced and are nearly identical, and they can be interconnected to provide higher functionalities. Because the modules can interconnect to form larger structures, I don’t have to build a complete space system on the ground, but I do have to make that module very reliable and very sophisticated.”
The modules are launched into orbit with enough internal propulsion to move to their destinations. At first, they behave as tiny independent satellites—until they find other modules or assemblies and connect to them. Once there, they serve as a component of the larger system, performing whatever their function is—data transfer, energy exchange, fuel supply, etc.—to help carry out the primary mission. “So that CubeSat goes up there and actually has its wherewithal, it moves—but imagine it just moves to the next one and bolts itself. If I can do that, if I can throw 10 of them up and bolt them up…. You don’t even have to bolt them because there are missions where they can fly together in close proximity and do something else. These ‘dances’ are all being directed by information that is flowing up from the ground,” Helvajian explained.
Moreover, the modules could be assembled to form nearly any shape. “We can keep throwing up a bunch of ‘smart tiles,’ park them in orbit, and when we have enough, send the commands to start assembling them. I just have to make each module very reliable and be able to produce it in large quantities—very much like how computer laptops are produced now. One develops a reliable manufacturing plant that makes these modules. In space, I can make something small by assembling four modules or something that’s a kilometer by integrating a million of them. Furthermore, after assembly, if a module fails, we just replace the module in space, which means there can be a continuous upgrade path. In biology, we learn that the cells you start with as a child are not the exact cells that you die with as an adult. There are many technical challenges, of course, but no violation of basic physics laws.”
Helvajian (right) and colleague Siegfried Janson (senior scientist) discuss the properties of an Aerospace CubeSat and how such a spacecraft would be realized in a glass-ceramic material.
The question becomes what structural material to use to make this module. Metal, silicon, and polymers have high lifecycle energy costs (i.e., mining, refining, and disposing). Helvajian and “a lot of very smart people” in his lab have been looking at glass ceramics, a versatile and inexpensive material, whose chemical and physical properties are particularly well suited for aerospace engineering (high strength-to-weight ratio) and photonics (transmitting, controlling, and detecting light). Photostructurable glass ceramics can be shaped and functionalized using laser lithography. “It’s all about functionalizing the material properties where necessary by controllably exposing it to laser light; making changes where you want things to happen. You can do that with light-sensitive glass ceramics. For example, one kind of exposure densifies the glass so visible light can propagate, another kind reduces the loss to radio-frequency propagation, another kind makes it chemically soluble so that patterned material can be removed. Recently, the Air Force released an announcement looking for glass ceramics that under laser light exposure become an electric conductor.”
The laser wavelength, the amount of photons applied, and the means by which they are applied all affect the material differently. Under the right conditions, the material is locally transformed to allow the growth and dissolution of different crystalline phases. AFOSR is now asking the question, “Can you take something like a doped glass that is still an electrical insulator, and locally convert it to have metallic properties?” Helvajian said that is going to be the test.
“We’ve demonstrated in our laboratories (along with other labs now joining worldwide) that material properties can be locally controlled with very high finesse using lasers. We have experimented with a commercially available photostructurable glass to vary its properties controllably—for example, to locally make it mechanically stronger or weaker—and have used this to fabricate glass MEMS. We can alter the radio-frequency transmission properties to enable fabrication of miniature antennas. We can locally alter the optical infrared transmission properties that make it useful as an optical filter. We can alter the chemical solubility such that the exposed material dissolves in acid at just the right rate or transform the material to make it high-temperature compatible. And as people begin to realize what can be done with controlled laser light exposure, it will open the opportunities of many different material transformations.”
Helvajian’s lab is developing the research on what needs to be done to make this happen. “A major step is getting manufacturers to start making these novel glasses so we can prove that what we say and we’ve done in our laboratories (albeit on a small scale) is possible on a larger scale. We’ve published on this—quite a bit, actually.”
Indeed, Helvajian’s publication record is extensive. “Research must be developed without micromanagement, but it also must be shared. If you don’t put your work out there for review, you will not know if you are walking down the right path.” His overall publications include more than 100 papers and 10 book chapters (he stopped counting a while back). He has also edited four books in microengineering aerospace systems and has more than 10 patents, two of which are licensed to companies that have so far resulted in royalties to Aerospace worth nearly half a million dollars.
Helvajian worries that research is not being given enough support today and is particularly lacking in the United States with regard to laser processing. “What is not done today will be felt 20 years from now. I work on ideas that can potentially take us into the future, 25 to 30 years down the line.” But he says it is not enough to do just the research. The modern scientist has to push the idea, get the right people excited about it. Scientists should also mentor students, he said. Over the years, Helvajian has mentored numerous graduate students from local universities. The last Ph.D. student, just two years ago, received her degree while doing all her research at Aerospace.
A Rising Star
Of Armenian descent, Helvajian was born in Egypt, where his grandparents had migrated during the Armenian genocide of 1915. When he was nine years old, his parents left Egypt, which was beset with class and religious tensions in the late 1950s, and emigrated to Southern California. Until that time, his mother had been his teacher. His formal schooling began in Los Angeles.
“We got here in 1963. Coming to the United States was wonderful, and it was a wonderful time. I was trying to assimilate myself, my background; I was trying to be something American, whatever that is. I was and still am multilingual. And I was enamored by what was going on in the space area—Mercury, Gemini, Apollo—I was following them all.” His fascination with the stars (“as in astrophysics”) grew. He also became interested in lasers and built one that actually worked and then developed a broadcaster that sent radio music on the optical wave. “My family had no college graduates on either side. There was no guidance for my future, but I knew I was interested in space and laser light.” The laser had just been invented and “used in a James Bond movie to ensnare another devotee.”
Two life-changing events happened during his years at Hollywood High. In his freshman year when he was 16, his father died, and as is Armenian tradition, he became “head of the family”—his mother, younger brother, and himself. In his junior year, he won a National Science Foundation summer program grant in lasers at the University of Southern California (USC). It was there that USC graduate students and faculty showed him his possibilities.
“They opened my eyes, and I am thankful for that. I honestly think we at Aerospace should do more of that here, especially at the Physical Sciences Laboratories. We do. We have students all the time in our building. I have them in my lab. But I think lots more of that should happen, because you do have an influence, you do have an impact on students of that age. My summer at USC affected me quite a bit.” Helvajian eventually won a scholarship to Stanford, where he earned his B.S. and M.S. in electrical engineering and quantum electronics. He earned his Ph.D. at USC in the same field but working in photochemistry. He joined Aerospace in 1984 following two years as a National Academy of Sciences postdoctoral fellow doing chemistry at the Naval Research Laboratory. Rick Heidner III (Aerospace Distinguished Scientist) “found” him looking for a job at a laser photochemistry conference, and offered him a position in his section that had both lasers and space. “A ‘no’ answer would surely have been tempting fate.”
—Donna J. Born
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