Hypersonic platforms, or aircraft and weapons that can travel at speeds in excess of Mach 5, have become a significant concern for the American defense apparatus over the past year or so. With the recent revelation that both China and Russia are quickly moving toward deploying operational hypersonic missile platforms, the U.S. has been forced to not only acknowledge that no existing missile defense system is capable of intercepting such fast-moving weapons, but worse, that America is currently years behind the competition when it comes to fielding hypersonic weapons of its own.

In 2018, Lockheed Martin was awarded more than a billion dollars to try to expedite a hypersonic weapon than can fill the capability gap represented by this apparent strategic blunder. But as one peruses weapons programs from the past few decades, one can’t help but wonder–where did this capability gap come from?

In 2004, NASA’s hypersonic flight research program made an incredible announcement: its purpose-built X-43A, a 12-foot long unmanned scramjet technology demonstrator, had done the seemingly impossible. It had reached an astonishing Mach 9.6 in a test flight fired from the wing of a B-52 Stratofortress.

Once again we made aviation history,” said Vince Rausch, Hyper-X program manager from NASA’s Langley Research Center in Virginia. “We did that in March when we went seven times the speed of sound and now we’ve done it right around 10 times the speed of sound.”

It was the culmination of the X-43A program, and at the time, broke the record for velocity from any flight vehicle set by the very same program a few years prior. The success was heralded as a leap forward in aviation technology, undoubtedly leading to breakthroughs that would allow for increased payload capacity and far greater speeds out of American military and even civilian aerospace endeavors in the years to come.

Then in 2010, the Boeing X-51 Waverider, another unmanned scramjet technology demonstrator, completed a successful flight test that reached Mach 5 at an altitude of around 70,000 feet. The engine did not fire for as long as the test intended, but surpassed the X-43 in the duration its scramjet functioned. Subsequent tests were conducted in 2011, 2012, and culminated with a flight that was considered an overall success in May of 2013–achieving a speed of Mach 5.1 and firing its scramjet for 210 seconds before the running out of fuel and crashing into the Pacific Ocean.

It was a full mission success,” Charlie Brink, X-51A program manager for the Air Force Research Laboratory Aerospace Systems Directorate, said in a statement.

In August of 2011, DARPA’s Falcon Project culminated with a flight test of the HTV-2, an unmanned glide vehicle that achieved the mind-boggling speed of Mach 20. The vehicle transmitted data back to the DARPA team for nine full minutes of continued flight. At those velocities, the HTV-2 could feasibly travel from New York City to Los Angeles in less than 12 minutes.

The initial shockwave disturbances experienced during second flight, from which the vehicle was able to recover and continue controlled flight, exceeded by more than 100 times what the vehicle was designed to withstand,” DARPA Acting Director Kaigham J. Gabriel said in a statement at the time. “That’s a major validation that we’re advancing our understanding of aerodynamic control for hypersonic flight.”

As recently as 2017, a joint American and Australian weapons initiative called HIFiRE conducted a successful test of a scramjet missile platform that reportedly achieved speeds greater than Mach 8.

This flight trial is a significant step forward in proving this technology and enhancing our collective understanding of how it could be employed across a range of applications,” Boeing, one of the program partners, said at the time.

All of these programs point toward a broad and robust approach to hypersonic technology, particularly in regard to the use of scramjets, which operate like traditional ramjets but, instead of reducing the speed of in-flowing air to subsonic velocities, utilizes the high speed to compress the in-flow of air, making for a highly-efficient engine platform for attaining and maintaining such high speeds.

However, in May of last year, Air Force Materiel Command commander, Gen. Ellen Pawlikowski, told reporters that the branch was developing plans for hypersonic platform testing, but warned that such tests would feasibly only be conducted “within the next couple of years.” The following month, Lockheed Martin was given multiple contracts adding up to more than a billion dollars intent on doing just that: fielding hypersonic weapons as quickly as they could to ensure America’s enemies aren’t fielding a weapon for which we have no response.

Lockheed Martin seems like a logical choice for the effort, after all, with a vast array of defense initiatives under its wing already, one of which is already expected to rely on scramjet propulsion to reach hypersonic speeds once it takes to the skies: the SR-72. What makes things a bit stranger, however, were remarks made by Lockheed’s Vice President Jack O’Banion about the SR-72 at the American Institute of Aeronautics and Astronautics in January of last year.

“Without the digital transformation, the aircraft you see there could not have been made,” O’Banion said while showing an artist’s rendering of the SR-72. As he continued to speak, however, his remarks seemed indicative of an aircraft that already exists, rather than one that remains squarely on the drawing board.

“We couldn’t have made the engine itself—it would have melted down into slag if we had tried to produce it five years ago,” O’Banion went on. “But now, we can digitally print that engine with an incredibly-sophisticated cooling system integral into the material of the engine itself, and have that engine survive for multiple firings for routine operation.”

He went on to say, “The aircraft is also agile at hypersonic speeds, with reliable engine starts.”

That doesn’t sound like a hypothetical replacement for the legendary Mach 3-capable SR-71 Blackbird so much as proud boasting about the testing of a platform that physically exists. Not simply an engine as is widely believed, but rather an entire airframe capable of being “agile” at hypersonic velocities.

The United States military has been at the forefront of hypersonic technology since its very inception–and yet somehow, within the past two decades, the official story is that America has not only lost the lead in this new realm of tech, but has seemingly lost the research and development already on the books. After nearly two decades of focus on counter-terror and anti-insurgency warfare, it stands to reason that these endeavors were simply placed on the back burner in favor of America’s short-lived belief that the days of near-peer warfare were over.

However, it seems equally feasible that America’s hard-earned expertise in hypersonic technologies has granted the nation an edge in this new realm of warfare: an edge Uncle Sam isn’t in a hurry to reveal.