Mach 6 aircraft: US vs Russia vs China, which country will get there first?
Companies, countries developing 'hypersonic' travel – more than 6x the speed of sound
The race is on to develop the world's first “hypersonic” aircraft.
The Mach 6-capable planes, using rockets instead of jet engines, are being developed in various places by startups with support from big powers — the US, China and Russia.
At about Mach 1, or “transonic”, a vehicle flies at the speed of sound (761 mph or 1,234.8 km/h). Mach 6 is six times faster than sound, powered by next-generation rockets propulsion technology.
Banned
For over 50 years, commercial supersonic (flying at speeds faster than 1,234.8 km/h) flight over land has been banned in the US (and about 20 years in the UK), because of the noise of “sonic booms”.
As such, since the Concorde (max cruising speed: 2,179 km/h) was retired, there have been no commercial aircraft even capable of supersonic flight.
Now, several manufacturers are actively developing new hypersonic aircraft. Hypersonic specifically means at least five times faster than the speed of sound.
Faster than Concorde
This new generation, faster-than-Corcorde type of hyper-speed aircraft are essentially missiles that could carry people, propelled by next-generation rockets.
Some of these futuristic planes will eventually be able to reach jaw-dropping speeds of up to Mach 6 (3,600mph/ 5,795km/h), according to project proponents.
What we know so far...
While it remains unclear if the bans on commercial hypersonic aircraft would be reviewed, these are the five organisations developing hypersonic planes and the countries where they are being developed.
Top 5 hypersonic aircraft under development:
#1. Venus Stargazer M4
- Speed: Mach 6 (approximately 3,600 mph)
- Proponents: Venus Aerospace and Velontra
- Country: United States
#2. XB-1
- Speed: Mach 1.5 (approximately 1,000 mph)
- Proponents: Boom Supersonic
- Country: United States
#3. SR-72
- Speed: Mach 20 (based on HTV-2 prototype)
- Proponents: Lockheed Martin Skunk Works and the US Air Force
- Country: United States
#4. Tu-2000
- Speed: Mach 10+
- Proponents: Tupolov Design Bureau
- Country: Russia
#5. Nanqiang No.1
- Speed: Mach 5 (approximately 3,000 mph)
- Proponents: Xiamen University
- Country: China
While this list is not exhaustive and there may be other hypersonic aircraft under development not publicly known, the speeds listed are estimates and may change as development progresses.
Interesting Engineering has reported that engineers at NASA’s Glenn Research Center in Cleveland and researchers at Venus Aerospace of Houston, Texas, are working with Nasa Marshall to identify how to scale the technology for higher performance.
On September 26, Venus Aerospace reported that it had successfully completed the first long-duration, high-thrust hot fire test of a Rotating Detonation Rocket Engine (RDRE), marking a significant milestone in our RDRE development.
“This achievement brings us closer to flying an RDRE in the near future, as the engine’s thrust-to-weight ratio is now on par with leading rocket engines in the industry.”
Challenges
Currently, supersonic flight over land is currently banned in many countries due to noise concerns. Researchers are working to develop quieter sonic booms.
The development of hypersonic aircraft could revolutionise air travel, offering faster and more efficient transportation options. The technology could also change wars.
• Venus Aerospace was selected for a Nasa Small Business Innovation Research (SBIR) continuing work on Rotating Detonation Rocket Engines (RDREs).
• In this project, Venus will work with Nasa to develop optimised nozzle contours by leveraging the RDRE hardware.
• The company said it will first transition its flight-proven model into a “reusable hypersonic flight system” to meet US Department of Defence needs for high-speed flight tests.
• The Venus Detonation Ramjet is a 2000-lb thrust engine.
Rotating detonation rocket engines (RDREs)
The technology behind the upcoming hypersonic travel is known as RDRE, which has rapidly evolved through contributions from various researchers.
Various companies and research labs have contributed to the development of RDREs, including Nasa as well as Russian and Chinese academic institutions.
• The model (prototype) being developed by Xiamen University will probably serve as a technology demonstrator for a hypersonic airliner. The model has undergone testing in a lab in the Chinese province of Fujian.
• In 2025, China will flight test a small drone, and construction of a 72-tonne hypersonic plane is expected to begin.
• They are targeting 2028 for flight tests of a hypersonic plane that could seat 10 passengers and are targeting 2035 for the start of commercial service for the hypersonic plane.
While the development of RDREs continues to be an ongoing process, researchers are working to overcome challenges and improve their performance.
In 2007, unconfirmed reports surfaced suggesting that Lockheed Martin was developing an aircraft for the U.S. Air Force capable of reaching speeds of Mach 6.
• Its primary goal was to function as a single-stage-to-orbit (SSTO) craft, capable of reaching orbit without the need for booster stages, similar to space shuttle concepts.
• The Tu-2000 was intended to utilise scramjet (supersonic combustion ramjet) technology, with potential top speeds exceeding Mach 10 (12,000 km/h or 7,456 mph).
• Though the project never flew, the design and technological insights gained from the programme continue to influence Russian hypersonic research and aerospace development.
Studies on RDREs
Improved Efficiency: RDREs have the potential to achieve higher specific impulse than traditional liquid rocket engines, meaning they can produce more thrust per unit of propellant. This can lead to increased payload capacity and reduced fuel consumption for space missions.
Enhanced performance: RDREs can operate at higher combustion temperatures and pressures, resulting in increased thrust and power output. This could enable faster and more efficient space travel.
• Lockheed Martin is also known to be collaborating with Aerojet Rocketdyne on the project, whose progress is crucial to developing the Hypersonic Missile project.
• In April 2010, Lockheed’s Hypersonic Technology Vehicle 2 (HTV-2), an uncrewed, rocket-launched aircraft, took its first flight as part of the Defense Advanced Research Projects Agency (DARPA’s) “Falcon” project. Its second was in August 2011. HTV-2 is designed to maneuver through the Earth’s atmosphere at hypersonic speeds.
• Airforce Technology also reported that the SR-72 aircraft is designed as a hypersonic aircraft capable of hitting targets on any continent within an hour. In this role, the aircraft’s high speed will theoretically enable it to penetrate protected airspace relatively easily.
Reduced emissions: Some studies suggest that RDREs may produce fewer harmful emissions compared to traditional rocket engines, potentially reducing their environmental impact.
Technological challenges: Despite their promise, RDREs still face significant technological challenges, such as maintaining stable detonation waves, ensuring efficient fuel injection, and managing heat transfer. Researchers are actively working to address these issues.
Takeaways
- Hypersonic vehicles represent a breakthrough, with the potential to revolutionise travels.
- RDRE propulsion systems have the potential to application in areas including space launch vehicles, hypersonic missiles, and power generation.
- If standing bans on commercial supersonic or hypersonic travel are lifted, RDREs may play a crucial role in future of travel.