Liners capable of flying several times faster than the speed of sound have appeared before. For example, NASA's X-43 experimental unmanned aerial vehicle accelerated to Mach 9.6 in 2004, and the North American X-15A-2 reached Mach 6.7, setting a record for a manned jet aircraft that remains to this day.< /p>
Recently, the field of hypersonic technology has attracted more attention from the military, to the point that it has become the newest arena of competition.
While the US, China and Russia are vying to develop their own hypersonic missiles, start-ups around the world are seeking civilian applications for these disruptive technologies that can cross the Atlantic in less than 90 minutes.
On March 10, Atlanta-based Hermeus announced that it has invested another $100 million to continue development of the hypersonic civil aircraft.
Among those participating in this funding round, — Silicon Valley insider Sam Altman, the Peter Thiel Founders Foundation, and tech venture capital firm In-Q-Tel. NASA is participating as a technology partner in the project.
Hermeus will equip its first prototype, called the Quarterhorse, with a so-called turbine-based combined cycle engine. Based on the proven GE J85 jet engine. This is a conventional power plant, which has long been installed on fighters such as the Northrop F-5 Tiger II. It will be combined with a ramjet engine.
Straight-through engine — it is a special type of engine that pushes air through a very simplistic shaft-like internal structure, devoid of moving parts or any air compression mechanism. The ramjet motors cannot be started from a static starting point, but are capable of very high speeds once they have reached a certain degree of forward motion.
In this regard, Hermeus assumes that the takeoff and landing phases will be the same as those of a conventional jet aircraft. It is only when the aircraft reaches cruise over the ocean that the ramjet engine kicks in and demonstrates its hypersonic power.
There is no public data yet on what costs this mode of travel will entail, and even less is clear about the expected ticket prices or expected earnings.
Given that the aircraft will carry no more than 20 passengers, and current regulations make it almost impossible to break the sound barrier when flying over land, there are only a few suitable markets left. For example, one of the richest and most popular routes in the world is London — New York.
The founders of Hermeus emphasize that prices are expected to be at the same level as in the usual business class.
Hermeus — is not the only startup working on commercial hypersonic models.
The Swiss startup Destinus, the brainchild of Russian physicist and entrepreneur Mikhail Kokorich, is developing an unmanned aerial vehicle capable of reaching astonishing speeds of up to Mach 15.
At this speed, a trip from Frankfurt, Germany to Seoul, South Korea, for example, takes only about 1 hour 15 minutes and Australia can be reached from Europe in less than 2 hours.
Destinus aims to do this by taking off into the mesosphere, one of the highest layers of the atmosphere, located at an altitude of 50 to 80 km. The aircraft takes off in the normal manner, then during the cruising phase of the flight it will traverse the low gravity mesosphere to eventually glide down to its final destination for a normal landing.
Destinus' original business is the express delivery of high value cargo. The prospect of capturing a slice of the $60 billion global express market was enough for the startup to recently receive $29 million in new investment from a number of venture capital funds and other private investors. If successful, the passenger transportation market could be next.
In November 2021, a few months after launch, Destinus flight-tested its first 1-tonne subsonic prototype near Munich.
Company plans to gradually scale it up: it wants to fly a 10-ton vehicle in 2027-2028 and a 100-ton vehicle by 2030. Moreover, it is planned to use liquid hydrogen, an experimental fuel, to reach zero emissions.