Are We Close to Supersonic Air Travel?
Jun 19, 2022
By Ambrose Li
We have gone from the historic Wright Flyer to the present-day Boeing 737. What’s next? You have to admit, although traveling is fun, the ride in the sky is not always so desirable. For example, traveling from Asia to Europe usually takes around 12 hours in the air. And during those 12 hours, you have to sit in an uncomfortable seat and do nothing. How boring is that! But do not blame the aeronautical engineers so quickly. We have been trying to increase flying speed for years now. For example, back in the 1970s, the Concorde was invented as the first supersonic passenger-carrying airplane. However, it was later canceled due to various reasons, including pollution to the environment as well as the loud noises it produces when traveling at supersonic speeds. After Concorde’s retirement in 2003, there appears to be no progress in the development of supersonic travel. What happened in the meantime? Not so “super” after all
While we could crack the way to travel at sound-breaking speeds, we could not do that in an environmentally-friendly manner. The first problem the aeronautical engineers encountered was the sonic boom. A sonic boom is a sound that is similar to that of thunder. When the aircraft breaks the sound barrier and flies at supersonic speeds, it will continuously produce sonic booms, which may be terrifying if it travels through a populated area. In fact, this is a problem Concorde encountered on its way to commercialization, as Europe, the U.S. and some other places have disallowed aircraft from traveling over land at supersonic speeds. Supersonic flights also consume a tremendous amount of fuel. For example, Concorde consumed twice the amount of fuel , yet carried only 1/4th of the passengers as compared to a Boeing 747. The energy efficiency was simply not good enough. Besides, supersonic aircraft release pollutants that worsen climate change. However, unlike regular planes, supersonic aircraft have to fly at a much higher altitude where the air density is lower. This contributes to a non-carbon dioxide warming effect . At high altitudes, supersonic aircraft release various chemicals , such as nitrogen oxides, soot (tiny carbon particles) and water vapor, into the upper atmosphere and produce contrails (the white line-shaped clouds that sometimes follow the plane). The emissions create a warming effect that is different from traditional greenhouse gas pollution by increasing the cloudiness of our atmosphere , though the result is the same – both deteriorate global warming. What’s more? The higher you fly , the more serious the problem becomes, since water vapor at a higher altitude has a longer lifespan, therefore prolonging the warming effect. Still, the crux of the problem remains fuel consumption. In fact, taking one return long-haul flight can result in more pollution than any other polluting activity in one year . In an era when people are paying more attention to environmental protection, you can easily tell why the project was banned afterward. Such factors have deterred many from taking part in supersonic projects. But after all these years, has there been any progress? We are working on it
In recent years, the topic of supersonic flights seems to have resurfaced. More and more industry leaders in the technology or aerial industries have been reportedly developing models that can address the concerns above. For example, NASA has been developing the project X-59 QueSST . The aircraft is said to be able to mitigate the loud noise of the sonic boom, one of the major issues with supersonic flights. In detail, the shape of the aircraft could spread out the supersonic shockwaves (where the loud noise comes from) in a particular way that the loud noise would not be present anymore. In fact, the company claims that the design would only hear a quiet “ sonic thump ”. The placement of the engine is also part of the consideration. It is located at the top of the aircraft so that the noise will be directed away from the ground. Right now, the project is still in the experimental stages. But if it works out, perhaps the ban from Western countries will be lifted, and we will see supersonic aircraft flying over us in no time. Additionally, the American company Boom has also been developing supersonic flights, and they are getting pretty close. Sustainability is one major issue Boom focuses on. For example, the company has been working with Prometheus Fuels . The fuel they supply can efficiently convert atmospheric carbon dioxide (CO2) into jet fuel. This undoubtedly mitigates the environmental impact of the fuels. In fact, on their website, they claim that they would be running on 100% sustainable aviation fuels. Similar to X-59 QueSST, they are also designing their aircraft so that it will address the current concern on noise levels. It appears that we are on the right track. When do we take off? Although the projects are still in the development stage, it will not be long before they are completed. The founder and CEO of Boom Supersonic, Blake School, estimates that their aircraft will be able to operate in 2030 . NASA, on the other hand, plans to fly the X-59 QueSST over certain areas to gather more data about its performance in mitigating the sonic boom in early 2024 . They would then deliver the results to the International Civil Aviation Organization and Federal Aviation Administration in 2027 to decide whether they would change the rules prohibiting supersonic flights over land. The results would come out as early as 2028 . It seems like we have a high chance of trying out supersonic flights ourselves within this decade. The development of supersonic flights marks another significant step for humanity. Not only is it a sign of our intelligence but also proof that technological advancement can co-exist with environmental conservation. Also read: