A future where hypersonic transport routinely carries passengers across continents is on the cusp of becoming a reality. Imagine a four-hour flight to Japan from North America, one that ferries an executive for a client meeting and brings him back home in time for dinner with his family. Or picture an influencer jetting off to Asia to feature a region’s distinct cuisine, then off to Europe to create a story about Antoni Gaudí and his architectural style–all in a day. Why not? Recently, the U.K. and the Australian Space Agency announced a collaboration dubbed as the world’s first “Space Bridge”. Remember the Concord and its supersonic speeds? The Space Bridge would be hypersonic, and that’s much, much faster.
Launched at the U.K. Space Conference, the project is aimed at making hypersonic transport the future of commercial aviation. The project will leverage on the SABRE (Synergetic Air-Breathing Rocket Engine) technology created by U.K.-based company, Reaction Engines Limited. If all things proceed as planned, travel time from the U.K. to Australia will be reduced to just 4 hours by the year 2030. With hypersonic speed travel, grueling transcontinental flight time can be cut by as much as 80 percent. For frequent business travelers, tourists and jet setters, this case is exciting news.
Breaking the Sound Barrier: Shockwaves and Melting Points
The fascination for flights at hypersonic speed began during the space race of the 1960s. In 1961, Russian and U.S. Space Missions achieved flights at a hypersonic speed of Mach 5. Notably, that record was surpassed in November of the same year when Air Force Major Robert White flew the X-15 research airplane at speeds over Mach 6. And the same aircraft, X-15, broke the record in 1967, with a speed of 6.7 Mach.
Despite these records, developments around hypersonic transport were sluggish. Sustained flights in hypersonic speed present a number of material problems. Essentially, traveling below the speed of sound keeps the temperature around the aircraft close to ambient air. However, aircrafts zooming at a speed of Mach 1 or above 1,236 km/h at sea level generate shockwaves. The shockwaves leave behind compressed gas molecules, which makes the temperature around the aircraft extremely hot. In the case of traveling at a speed of Mach 5 (3,800 mph), the temperature around the aircraft can reach 2,200 degrees Celsius.
The intense temperature associated with shockwaves will damage and melt the engine. With this material limitation, rockets carry their own liquid oxygen to cool the aircraft’s engine during combustion. However, the added weight of the liquid oxygen makes rocket propulsion engines impractical for sustained hypersonic speed flights.
Is Hypersonic Transport Ready for Take-Off?
Experiments around high-speed engines continued through the decades, and various technologies were developed. One of these technologies is called the Scramjet or Supersonic Combustion Ramjet. The idea was to harness atmospheric oxygen instead of carrying liquid oxygen on flight. By using high-velocity forward motion, air is compressed into the engine, mixed with fuel, and expelled on the other side of the engine to create thrust. Test flights were conducted since 1960s. However, significant progress was only accomplished around the 2000s. The first successful test flight at hypersonic speed was achieved in May 2010. NASA and U.S. Air force’s X-51A Waverider flew at the speed of Mach 5.
Fast-forward to 2019. Building upon the Scramjet technology, Reaction Engine’s SABRE engine aims to improve hypersonic transport by utilizing hydrogen and oxygen in the atmosphere. With backing and investment from government space agencies, Boeing, Rolls-Royce, and BAE Systems, the company is eyeing test flights by the year 2020 and commercial flights in the year 2030.
Another company joining the hypersonic transport race is Airbus. The Europe-based manufacturer of the now-defunct Concorde is hard at work designing a “Zero Emission Hypersonic Transport (ZEHST)”. Airbus expects to deploy its ZEHST by the year 2050.
Hypersonic Transport with Hypersonic Speed: Safe, Efficient, and Fast Travels Around the World
The technology that can support hypersonic transport is finally beginning to take shape. Moreover, air travel is soaring, and its growth is expected to double in the next decades. Commercial aviation must be prepared to keep with the demand. Additionally, safe, efficient, and reasonably-priced hypersonic transport is the goal. Hopefully, commercial aviation will be able to keep up with the demand and find ways to better serve the growing population of enplaning passengers.
It’s true that the Concorde Supersonic was grounded for good in 2003. From then on, commercial aviation had to park its dream of high-speed flights. But with the recent developments in hypersonic transport, there might be another reason to look up in the sky.