This Russian Scramjet Capable Of Mach 6.5 Is for Sale
What you are looking at is called a Kholod. In 1991, this Russian/NASA joint project smashed every record when it reached a sustained speed of mach 6.47, or just a tick over 4,300 mph, using a type of propulsion—called a scramjet—so ridiculously simple to understand that it’s amazing it’s still considered hyper-advanced, even by today’s standards.
The Kholod uses traditional rockets to get up to supersonic speed before switching to the scramjet. The air at supersonic speeds is greatly compressed as it enters the scramjet, then cryogenically cooled hydrogen is added, and when everything combusts, the force is enough to theoretically go up to and beyond mach 15...though if any vehicle has hit those speeds in the atmosphere, it hasn’t yet been publicly disclosed.
It was a strange journey to get as far as it did. The Russian Institute for New Propellants (CIAM) initially worked to transform the jet from a theoretical concept into a reality. Its first launch was in the waning weeks of the Soviet Union’s existence, and in the years that followed, CIAM worked with engineers from both France and NASA. This is when the fun began.
Today, it’s best suited as a museum piece. The Kholod might be one of mankind’s most amazing feats of engineering, but it’s anything but practical. It’s estimated that the French engineers spent over $200,000 just on one launch, and that was 23 years ago. Plus, it’s designed to fly incredibly fast across a given trajectory, at which point it simply falls back to Earth at a horrifying rate. Still. Mach 6.5, you know?