Wow! NASA Building ‘Quiet’ Supersonic Transport
NASA is best known for landing men on the moon, operating the International Space Station, and sending robotic probes to every planet in the solar system. Less known to the public, NASA also engages in aeronautical research and development, building and testing experimental aircraft to advance the technology of flight.
It is in that spirit that NASA has given the green light to build and test the X-59, a prototype of a supersonic transport, but one that does not create the noisy sonic boom the other aircraft create when they fly faster than sound. The prototype, due to start flying in 2021, may revive the idea of supersonic airlines that were first attempted in the early 1970s. The last of the supersonic transports, the Anglo-French Concorde, was retired from service in 2003.
According to Fox News:
“The plane, designed and put together by Lockheed Martin, has a long, pointed nose and is built so that the sonic boom sound is reduced to a ‘gentle thump’ or possibly no sound at all, NASA added. The new plane’s sound when passing by will register around 75 Perceived Level decibel, much lower than a Sonic boom, which comes in at 90.”
The X-59 will be flown over various communities where sensors and human observers will be able to note how loud its passage will be. Earlier supersonic transports were banned from flying over land because of the loud noise they cause as a result of a sonic boom.
In the 1960s, the United States subsidized a program to develop a supersonic transport or SST. However, the sonic boom problem, the idea that its exhaust would damage the ozone layer, and its immense cost finally caused Congress to cancel the program in 1971. The Soviet Union developed its own SST, but it was relegated to cargo flights inside the USSR.
The Anglo-French Concorde began service in the mid-1970s, flying the transatlantic route between London and New York and Washington. However, the economics of air travel had changed since the project was first conceived. Large airliners such as the Boeing 747 competed successfully with the Concorde because of the sheer number of people they could fly between Europe and North America. The Concorde was never profitable during its service. The air travel slump after 9/11 finally killed the supersonic airliner.
The X-59 will be able to gather data that will help regulators establish new rules for supersonic travel over land. If a commercial supersonic transport can be built that can fly over land without bothering people on the ground, then the economics of supersonic air travel might change.
According to Flight Sphere, a person riding an airliner between New York and Los Angeles can expect to spend about five and a half hours in the air, traveling 2475 miles. If he or she were riding in a supersonic transport that flies at the same airspeed as the X-59, 940 miles an hour, that time is reduced to 2.6 hours.
One of the other factors that made 20th Century SSTs uneconomical was the fact that they tended to be fuel hogs compared to conventional, subsonic airliners. The French and the British initially subsidized the Concorde to make it more attractive to passengers. However, the Concorde remained a plane that only business travelers with fat expense accounts and the very wealthy could afford. The few extra hours spent over the Atlantic were worth avoiding the price of a seat on the Concorde.
However, air travel analysts have noted that if an SST can be developed that can travel over land as well as the water, it might serve the same niche market as the Concorde did at a premium that is still low enough to turn a profit.
On the other hand, some airliners might prefer to compete on the basis of cost and service rather than speed. Air travel is uncomfortable because of post-911 security concerns and the tendency of airlines to cut space for passengers. Airlines that can mitigate these factors could get a better competitive advantage than those going for speed.
Finally, SSTs may run into opposition from environmentalists. The carbon footprint of supersonic transports would be immense. In an era when people are trying to cut co2 emissions, adding to them to gain a little speed in the air may be considered problematic.