Imagine a 10-seater private jet that uses rocket boosters to take off, detaches these at an altitude of 12km, fires its supersonic engines to hit speeds of Mach 24 (20,000 km/h), and gets you from New York to London in 11 minutes.
That’s the idea behind the Antipode, a next-level concept jet by Canadian inventor and engineer, Charles Bombardier. The concept comes just months after Bombardier unveiled his designs for the Skreemr, a four-winged scramjet that could carry 75 passengers at speeds of up to Mach 10 - so, 10 times the speed of sound and five times faster than today’s Concorde jets.
As Fiona MacDonald reported for us back in October, scramjet systems are powered by combusting liquid oxygen, and instead of carrying that liquid oxygen on board like traditional propulsion systems, they use oxygen extracted from the atmosphere passing through the aircraft. This means that the whole plane becomes a lot lighter, and therefore faster.
"But in order to work properly and compress the incoming oxygen without the need for moving parts, scramjets need to be travelling faster than the speed of sound, at around Mach 4, which is something that no passenger plane has ever achieved - Concorde maxed out at Mach 2.0," says MacDonald.
Let’s just put it out there right now that not even NASA has managed to develop a reliable scramjet system. And not to mention how uncomfortable it’s going to be for all those billionaire passengers zipping through the sky at 20,000 km/h.
But all of that aside, there is a problem with the system that Bombardier thinks he can actually solve: figuring out how to ensure that the wings and nose of the plane don’t overheat when travelling faster than the speed of sound. "I am not sure the materials able to withstand the heat, pressure, and structural stress for this application have been invented yet," he said last year.
Now he says he might just have the solution, and showcases it in his even more ridiculous 'Antipode' hypersonic concept jet. "I was contacted by [Wyle engineer and former Department of Defense RIAC director] Joseph Hazeltine, who proposed using a novel aerodynamic phenomenon called ‘long penetration mode (LPM)'," he told Kristin Tablang at Forbes.
If all of that just sounded like a bunch of words strung together with no meaning, don’t worry. What Bombardier is describing is actually pretty simple.
Firstly, unlike the Skreemr - which would use a magnetic railgun system to take off - the Antipode would launch into the air using twin rocket boosters attached to its wings. Once the jet reaches an altitude of 12 km and speeds of Mach 5 (which is well beyond the speed of sound), the rocket boosters drop off and zoom back to the base.
So far so good. Then the supersonic combustion ramjet engine would be fired by the onboard computer and the plane accelerate up to Mach 24. Enter the serious overheating problems.
Bombardier says his new plane would combat this by cooling everything down with strategically placed jets of air. "It would channel some of the air, flowing at supersonic speed, through a nozzle located on the nose of the aircraft, producing a counter-flowing jet of air that would induce LPM, which would in turn lead to a drop in surface temperature due to aeroheating and a reduction of the shockwave and noise caused by breaking the sound barrier," Tablang reports for Forbes.
Unfortunately for the Antipode, LPM works best on spacecraft that are designed like rockets - with as little exposed surface area as possible. Those huge wings it’s got? Yeah, they’re not exactly ideal, and Bombardier knows it. "The Antipode’s current configuration does not reflect an optimal shape in that regard," he admitted to Forbes.
So nope, this thing isn't coming to a billionaire bachelor party landing strip near you any time soon, but hey, at least someone’s throwing these crazy ideas around. Because a) maybe someone more qualified will actually end up doing something with them, and b) it’s important to dream big.