Can you imagine an aeroplane travelling faster than the speed of light? Well, that is definitely not possible, for nothing can travel faster than the speed of light. But, it will come as a surprise to many that an aircraft may travel faster than the speed of sound, which is 343 metres per second. The speed of sound is also called Mach 1, and anything faster than this, up to Mach 5, is said to be supersonic. An interesting example of a supersonic aeroplane is NASA’s X-59 quiet supersonic aircraft.
On January 12, 2024, NASA and Maryland-based aerospace firm Lockheed Martin formally unveiled X-59, an experimental quiet supersonic aircraft, outside Lockheed Martin’s Skunk Works Facility in California. This one-of-a-kind research aeroplane holds immense significance in aerospace because it is expected to lead to an era of commercial aircraft that can travel faster than the speed of sound.
Now, a few questions arise: can we hear supersonic objects, and why do we need a quiet supersonic aeroplane? Well, if one looks up at a supersonic aircraft from the ground, they will not hear anything initially because the plane is travelling faster than the speed of sound. But they can hear a sonic boom a few seconds after the plane has passed.
Coming to why the world needs quiet supersonic aircraft, the answer is that they will help reduce noise pollution. This is the aim of X-59, which is an important part of NASA’s Quesst mission.
The objective of Quesst is to address a primary challenge to supersonic flight over land by showing how the X-59 can fly supersonic without generating loud, sonic booms, and then analyse what people hear when the aircraft flies overhead. In other words, Quesst aims to make sonic booms quieter.
This is because for years, aviation regulators from the United States and other countries have prohibited commercial supersonic flight over land due to the disturbance caused by loud, perturbing sonic booms to the people living below.
Therefore, a supersonic aircraft with quieter sonic booms will ensure that noise pollution is avoided, and people will not be disturbed. NASA aims to analyse such data by experimenting with X-59, so that the space agency can share people’s reaction to the quieter sonic thumps with regulators who, in turn, can consider devising new sound-based rules to revoke the prohibition on supersonic flight over land.
