U.S. Must Remain Committed to Hypersonics.

• Author: Wostenberg, Rebecca
• Position: Emerging Technology Horizons

* 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 boomand-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...