So, to be more specific, we are going to work on technologies such as revolutionary new configurations, meaning that the configuration of the aircraft now will look different – completely different – from the tube and wing configuration that mostly all large transport aircraft adhere to now. We envision aircraft configurations something like a flying wing, looking somewhat similar to a flying wing. We call it a hybrid wing body, but that is a configuration that is very promising to reduce emissions and noise dramatically from the current configurations. So we’re going to work on that kind of revolutionary configuration.
We’re also working on ultra-high bypass ratio engines and even unducted fan engines, so those engines also will be very much advanced and different from today’s aircraft engine systems. Also fuel efficient and ultra-low emissions combustors to, again, reduce emissions. And lighter materials and structures to reduce fuel consumption, which will directly contribute to a reduction in CO2 emissions.
So, we have a number of promising technologies, but sometimes these promising technologies compete against each other. As an example, if you want to reduce noise, you want to do some treatment to the inlet and nozzles of the engine, but then the measures you are taking to reduce noise may actually hamper the performance of the engine. So, the key point is to simultaneously reduce emissions and noise while maintaining the performance of the aircraft. That’s why we need to put the most promising technologies from various parts of the aircraft, integrate them, and assess the intended integrated benefits, how much is feasible, and what areas need to be adjusted, and so on and so forth. That’s kind of, in a nutshell, what we are trying to do.
NTB: Another program high on your directorate’s priority list is the Next generation Air Transportation System, or NextGen for short. Tell us about NextGen.
Dr. Shin: Yes, that is another hugely challenging area for the country. I’m sure I don’t need to belabor this point to you, and most of your readers will recognize this as a national challenge.
NTB: Anyone who travels by air will recognize it, correct?
Dr. Shin: Yes, that’s it exactly. Currently our national air space system and the way to handle the traffic is almost at the choking point, based on the current surveillance system and air traffic management procedures and processes. That’s why during the holiday seasons or during the summertime when a lot of disruptive weather happens around the country, you end up getting a lot of delays and cancellations of flights.
So, a kind of interesting outlook is the community thinks that air traffic volume will grow two to three times the present volume in the next twenty or twenty-five years. By the 2025 timeframe, it is not out of the realm of possibility that air traffic volume could be doubled from, perhaps, the level of 2000, right before 9-11. How to handle this capacity is a huge issue, but at the same time environmental impact consideration is growing rapidly. In view of that, concern is getting even bigger so some countries, European countries, are starting to regulate the aviation industry simply because of emissions and noise considerations. And safety is also going to be a big challenge because currently the aviation industry has been enjoying almost a mind-boggling level of safety. At least in the U.S. and developed countries worldwide, air transportation is the safest mode of transportation.
But when future systems become more and more automated and highly diverse, we envision that new aircraft capabilities will come in like UAVs – unmanned aerial vehicles – and perhaps even supersonic airplanes. Also, perhaps, a large civil tilt rotor, like a V-22 Osprey aircraft, but for civil use. So, some of these new capabilities may be introduced and a lot of automation will happen, both on the aircraft systems and also ground tracking systems, and navigation surveillance technologies will advance.
So when you put all these potentials together, the incremental improvement will not be able to address the future challenges. So NextGen was conceived to create a revolutionary change, a transformation in air transportation systems, and technology is a big piece of it. Certainly policy and procedures and all those things are still required to support new systems, but technology is the centerpiece of this revolution. That’s why NASA is heavily involved in developing next-generation technologies.
NTB: In 2009 you testified before members of congress regarding NASA’s research efforts in the area of powering future aircraft with second and third generation biofuels. How is that research going and how far off in the future do you envision achieving that goal?
Dr. Shin: I certainly believe biofuels hold a lot of promise. Several airlines have already flown using conventional jet fuel mixed with some type of biofuels, so it’s already been demonstrated that biofuels are very legitimate and viable alternatives to the fossil fuels that are propelling aircraft at the moment.
The challenges, actually, are numerous for biofuels, as you might expect. Really cost-effective manufacturing is a huge challenge. I don’t want to go into all of the details, but the land mass required to grow enough quantity…you’ve heard all the stories including the grain and stuff that we need, and water resources, and so on and so forth. But cost-effective manufacturing and enough quantity and all that are the important challenges.