Summary and Key Points: The X-51 Waverider, an experimental hypersonic aircraft, reached speeds up to Mach 5.1 (3,400 mph). Launched in 2005 by Boeing Phantom Works with DARPA and Air Force Research Laboratory support, it tested air-breathing scramjet propulsion.

-Launched from a B-52, it used a solid rocket booster before switching to a scramjet engine, flying over six minutes and covering 230 nautical miles. Despite successful tests, the U.S. ended the program in 2013, lagging behind Russia and China in hypersonic weapons.

-U.S. overemphasis on research and dual-use technology transfer to Russia hindered progress, leaving the nation vulnerable to emerging hypersonic threats.

The X-51 Waverider: Pioneering Hypersonic Flight and America’s Missed Opportunity

The X-51 Waverider was an unmanned, experimental hypersonic aircraft that was designed to reach speeds of up to Mach 5.1. (That’s 3,400 miles per hour for all you folks who get around the place at conventional speeds.) 

The X-51 was first launched in 2005. 

This insanely fast bird was built by the legendary Boeing Phantom Works. America’s X-51 program was augmented by contributions from DARPA and the Air Force Research Laboratory.

The Waverider was developed to test the feasibility of air-breathing, high-speed scramjet propulsion. This was a proof-of-concept plane that was meant to both push the limits of what were then advanced weapons and delivery systems, as well as to develop a more cost-effective way to access space. 

Mind you, this was before the advent of Elon Musk’s SpaceX and their reusable rocket system. 

The Process of Launching This Bird

Launched from a B-52 Stratofortress bomber, the X-51 Waverider would accelerate to hypersonic speeds using a solid rocket booster and then switch to its scramjet engine, which would burn a mixture of ethylene and JP-7 jet fuel to maintain its absurdly fast speeds. 

The X-51 could then fly for over six minutes and cover a distance of more than 230 nautical miles (or 264.7 miles). 

There were few other hypersonic aircraft programs out there. NASA had the X-43 that could reach speeds of up to Mach 9.6. The Russians built their GLL-8, which could hit Mach 6. But the X-51 was unique in its use of a scramjet engine, which allowed it to sustain hypersonic flight for longer periods of time than any of those other systems mentioned. 

America’s experimental X-51 Waverider made its final flight on May 1, 2013. The unmanned scramjet-powered vehicle flew over six minutes, reaching a top speed of Mach 5.1 as it was designed to do. With that successful final flight, the program was terminated, and the technology was folded into future hypersonic flight research for the United States. 

Despite this, the United States today lags its strategic rivals – notably Russia and China – in the development and deployment of reliable hypersonic weapons.

America Missed the Mark on Hypersonic Capabilities

There are a number of reasons for this. 

For starters, despite having an early lead over its rivals, the United States spent more time in the research and testing phase of hypersonic systems than it did in developing workable, real-world weapons based on the experiments they were conducting. There was also a lack of need. Back when the U.S. military was investing in experiments with such systems, it seemed like a stretch that they would ever be used. 

The primary threats to the United States at the time came from non-state actors, such as al Qaeda, and rogue regimes, such as Iran or North Korea. None of these rivals had hypersonic weapons, nor did they express much of an interest in acquiring such capabilities. America took its leading position for granted.

Sadly, there are darker reasons as well. 

Here’s Why America Missed the Mark

Not only were U.S. leaders ambivalent about the need to build reliable hypersonic systems in the near term, but they allowed for dual-use hypersonic technologies to be passed on to Russia during the Obama administration. In fact Russia today, unlike the United States, has an arsenal of functioning hypersonic weapons that it has already deployed in the killing fields of Ukraine.

Meanwhile, the Chinese went about building some of the world’s most advanced infrastructure to support long-term, expensive, and radical R&D projects for hypersonic technology development. What’s more, China has built one of the most sophisticated hypersonic glide vehicles in the world, whereas the United States is struggling to build its own reliable systems.

And because the United States never fully prioritized the development of hypersonic capabilities while it enjoyed a decisive lead over potential rivals, with those rivals now in possession of working arsenals of hypersonic weapons, the United States lacks any serious defense against them. 

This poses a particular problem as hostilities between the great powers seem likelier than ever. Any potential great power war will not only be relegated to distant shores. It will be fought there as well as here. Such a fight will see scores of hypersonic weapons coming our way.

The Americans missed the opportunity to outpace their rivals in this critical technological domain. The X-51 Waverider was a true marvel of engineering that pushed the boundaries of what we thought was possible in the world of hypersonic flight. When that program ended, another bigger and more comprehensive program should have replaced it. That never happened, and it may prove to be a critical mistake. 

About the Author 

Brandon J. Weichert, a National Interest national security analyst, is a former Congressional staffer and geopolitical analyst who is a contributor at The Washington Times, the Asia Times, and The-Pipeline. He is the author of Winning Space: How America Remains a Superpower, Biohacked: China’s Race to Control Life, and The Shadow War: Iran’s Quest for Supremacy. His next book, A Disaster of Our Own Making: How the West Lost Ukraine, is due October 22 from Encounter Books. Weichert can be followed via Twitter @WeTheBrandon.

All images are Creative Commons. 

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