U.S. Must Remain Committed to Hypersonics

X-43A

NASA photo

On Oct. 1, 2019, the People’s Republic of China celebrated its 70th anniversary with full authoritarian pomp and circumstance. Amongst the pageantry of the massive military parade, China publicly flaunted the Dongfeng-17, a medium-range missile system equipped with a hypersonic glide vehicle.

Although the U.S. was aware of the existence of the DF-17, the parade highlighted two significant questions: first, why do hypersonic weapons matter, and second, how did China beat the United States in fielding a hypersonic capability? The answers are complicated and include over 60 years of boom-and-bust cycles in America.

Hypersonic weapons, including maneuvering missiles flying at least five times the speed of sound, or Mach 5, within the Earth’s atmosphere, can deliver long-range lethal effects on short time scales. In other words, if an adversary is launching missiles that take minutes to reach their target while U.S. missiles take hours, we will be at a significant disadvantage. Similarly, speed limits the decision time for adversaries, thus getting inside their decision-making process or “OODA” loop.

Speed is not the only advantage of hypersonics. Their value also lies in maneuverability and the altitudes at which they fly, which, when combined with speed, make them very challenging to detect and therefore defend against.

The United States once had a significant advantage in its stealth technology, but our adversaries have learned over the years how to counter stealth and have developed their own capabilities. Hypersonics have been called the next thing after stealth; but if hypersonic weapons are critical to national defense, why has the U.S. not already fielded the technology?

Traveling at hypersonic speeds is nothing new. Every intercontinental ballistic missile or civilian space probe reaches hypersonic speeds upon reentry. However, developing a successful maneuverable vehicle that can travel at sustained Mach 5-plus is a significant challenge. In the early 1960s, the U.S. Air Force developed the concept of a “spaceplane.” By the 1980s, the concept had morphed into the National Aerospace Plane Program. NASP was a $3.3 billion joint Defense Department-NASA program to build an affordable plane that could travel up to Mach 25-plus from the Earth’s surface into space, taking off and landing from conventional airfields.

The program was ultimately canceled when Congress ended the funding in 1994, with only a few test articles and modeling tools to show for it.

NASA built on the NASP work with its X-43 subscale aircraft, one of which flew to Mach 7, and another to Mach 10, in 2004. Although the X-43 was considered a technical success, politics and personalities got in the way and there was no follow-on to the program.

The Air Force later pursued its own hypersonic flight test program, the jet-powered X-51, which flew successfully in 2010 and 2013, but was also not continued after those first flights.

Following X-51, the majority of the Pentagon’s hypersonics efforts were managed by the Defense Advanced Research Projects Agency.

Instead of expanding on the previous proven designs, DARPA opted for entirely new programs. The agency had also been pursuing a rocket-boost glide approach with its Hypersonic Technology Vehicle 2, originally designed to fly in the Mach 20 range and reach transcontinental distances. After several failed tests in 2010 and 2011, DARPA discontinued the HTV-2. Instead, a joint DARPA-Air Force initiative called the Tactical Boost Glide program began, building on the research derived from the HTV-2 but scaling back the speed and distance.

China took note of U.S work in the field, including several open policy documents that explained the value of hypersonic weapons, and dramatically increased the pace of its own hypersonics program by stealing information and using legal and illegal means of acquiring U.S. research and technology. These efforts culminated in some of the successful hypersonic missiles China displayed in 2019.

With Chinese capabilities surpassing those of the United States, it is imperative that the Defense Department prioritize hypersonic weapons.

The past few years have shown positive developments in this area.

First, the United States needed a clear path forward. The “hypersonics roadmap” released by the Defense Department last year is an important first step. Now we need to stay the course.

Second, in a time of fiscal constraints, hypersonics are a vulnerable big-budget item. The funding has weathered the first test, as shown by the Pentagon’s fiscal year 2022 budget request that included $3.8 billion to field hypersonic weapons on air, land and sea platforms.

However, Congress will have the final say. That funding must be sustained for the long run.

Next, the United States needs more hypersonics infrastructure — including testing and evaluation facilities.

Finally, the government needs to be less risk-averse when it comes to flight testing. Noble failures — where we learn lessons — are simply part of testing. The Defense Department and Congress must be willing to accept risk of failure if we are to finally transition hypersonic weapons from prototyping and development to a fully fielded capability. Our national security depends on it.

Rebecca Wostenberg is a research fellow at NDIA’s Emerging Technologies Institute.

Topics: Emerging Technologies, Defense Department