How Earth-Friendly Will the Skies Be in Twenty Years?

Ready or not, the future is being created now, partly by deliberate planning and partly by colliding circumstances. Some of that deliberate planning, particularly with regard to aviation, just got a jumpstart thanks to the folks at NASA’s Aeronautics Research Mission Directorate in Washington. The agency's Fundamental Aeronautics Program is focused on developing technology that will enable aircraft to meet national goals for reduced fuel consumption, emissions and noise. They have just awarded a total of $16.5 million to four industry and academic teams in a program that is known internally as N+3 which means that the technologies being developed are targeted three generations of aircraft into the future, in the 2030-35 timeframe. This is far more futuristic than the $125 million in research funded by FAA last year.

The four NASA contract winners are:

• Boeing Research & Technology, Huntington Beach, CA $8.8 million


• Massachusetts Institute of Technology, Cambridge, MA $4.6 million


• Cessna Aircraft Company, Wichita, KS. $1.9 million


• Northrop Grumman Systems Inc., El Segundo, CA $1.2 million

Boeing will be continuing work on their Subsonic Ultra Green Aircraft Research (SUGAR) Project, which is looking at truss-based wing aircraft designs and hybrid electric engine technology. Under the contract, the team, which also includes GE and Georgia Tech, will design, construct and test wind tunnel mockups and computer models of the airplane. They will also evaluate lightweight materials and engine concepts for even more futuristic planes targeted between 2040 and 2045.

The MIT team is moving forward with work on its "double bubble" airplane design, a a dual fuselage concept with two partial cylinders placed side by side, that would create a wider structure than the traditional tube-and-wing airliner. The team will also explore the challenges of high-efficiency, small-core engine technology - the idea that it is not necessary to increase an engine's size to increase efficiency in delivering power. MIT’s green plane is estimated to use 70% less fuel that today’s aircraft while reducing NOx emissions at the same time and requiring shorter runways. MIT will be partnering with Aurora Flight Sciences Corporation and Pratt & Whitney on this project.

Cessna will be investigating a new “magic skin” which has the intriguing acronym of STAR-2, which stands for Smoothing, Thermal, Absorbing, Reflective, Conductive, Cosmetic. That pretty much says it all doesn’t it? The smoothing makes it quieter and more slippery, thermal, absorbing and reflective all work to keep it comfortable inside (which could reduce the need for additional heating and cooling). The conductive part helps protect from both lightning strikes and radio interference, and I think the cosmetic part speaks for itself. An additional feature of this skin is that it is self-healing, which means that rips and tears automatically seal themselves up. That’s particularly interesting in the light of last week’s Southwest Airlines incident.

The Northrop Grumman team will focus specifically on looking for a breakthrough in the design of the leading edge of the wing. If engineers can design a smooth edge without the current standard slats, airplanes would be quieter and consume less fuel at cruise altitudes because of the smoother flow of air over the wings.

Some analysts have suggested that heavier-than aircrafts are a luxury we might not be able to afford if we are going to rein in our carbon emissions to a level sufficient to stabilize the climate. Indeed, some including the American Institute of Aeronautics and Astronautics, are suggesting that lighter-than-air craft (i.e. blimps) will be making a comeback.

So how bad are the carbon footprints of today’s jetliners? The answer is it depends on a number of factors, including which airplane, how full it is, and how far it is travelling. On long haul flights, like NY to LA, the numbers range from 1924 to 6732 pounds of CO2 per person. That is equivalent to anywhere between 9 and 31 miles per gallon in a car, with the higher numbers generally coming from the newer designs. If we take the average of 20 mpg and add a 70% improvement, that gets us up to 66 mpg, which sounds pretty impressive. Unfortunately, it’s a little more complicated than that because of something called Radiative forcing. This is an amplifying effect that comes from putting the emissions out at high altitudes. Unfortunately, this has not been well quantified, though it is expected to increase the impact by anywhere from 50-500%.

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RP Siegel is the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water.  Like airplanes, we all leave behind a vapor trail. And though we can easily see others’, we rarely see our own.

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